Hey Michael, I saw your update. But I didn't understand how we can apply the philosophy of Dave Rat (sub on separate send) without using an aux. Maybe using a group feeding a matrix dedicate to the sub. That seems very similar. Thanks for sharing your knowledge.
Thanks for this article. I have been constantly wondering about this since working in live sound and tend to be of the same opinion. I've done it each way, but it really does seem to me (coming from the studio, and thinking from a translation perspective - be it for streaming/broadcast or for a feed to another room) that it's better dealing with the PA as if it were a single full-range playback system. I can understand the business with the transfer function, but even working in a 1000 person capacity room where visiting engineers often use SMAART, I really haven't seen them monitoring it during the show. They're just using their ears then and working the mix, or EQ'ing the master GEQ a bit to compensate for what they're hearing.
It's like a lot of things in audio: it's one way of doing it. I've found over the years that it's better to stay away from holding an opinion that states someone should never do something. Some of the reasons I love using aux fed subs is that I don't have to HPF nearly everything. I don't want acoustic going to the subs and I don't want a HPF on it. I also love having the ability to give the subs more level at lower volume to compensate or giving them a bit of a boost to emphasize some moments. Yes, the acoustic crossover changes, but while system design is linear and analytical, running sound is not. There is room for some of the artistic opinions and if no one gets hurt, then go for it.
Thanks for weighing in here, Steve. You're totally right. It's one way of doing it and you're more than welcome to run your shows how you see fit. And you probably get great results for how you put together a mix.
@@steve01010 Thank you very much! I appreciate you being able to hold the tension of "sure, we don't agree on everything", but still appreciate what else I have to say. Glad it's been helpful to you.
@@__Nata_he’s saying he doesn’t want a HPF on the acoustic instrument (and many other inputs), which usually cuts off most content going to the subs (though the HPF on most digital consoles is adjustable).
08:30 Sure you can send group to an aux on x32: 1. take 2 free channels, link them to be stereo 2. choose the input of those channels - the buses of the group 3. send the channels to an aux as usual
I have been a concert engineer for over 20 years now, so I live by the motto of not telling another engineer how he should do things, just like I wouldn't tell a musician how to play HIS instrument. That said, I feel that some of the things you mentioned were made for the wrong reasons. I am neither an electrical engineer nor a comp programmer, so I don't know the exact physics of what is going on under the hood. But, there is a stereo summation from Main LR, that gets decorrelated when moving to Matrics. When I was first shown the difference, I had to go back to my shop and experiment for myself. With a 2 tops over 2 subs a side, stacks, I wired 1 top to 1 sub on each side with one amp system, while hooking up the second speaker set to a like amp system. Being able to A/B the two set-ups with one being fed main bus and the other from matrics. There is a noticeable fidelity change from one output to the other. As for the lack of full range on your main L/R bus, when using subs on an aux, your left/right outputs are still seeing full range, and anything that you matrix off of your L/R is still full range. Your sub is only affected after your system crosses over at its designed frequency, With that being said, your sub send will also send a full range signal to the sub channel of your amp, where at that point, your system will cross over, filtering all other frequencies from that full bandwidth signal. With proper "system" gain structure, there should be no audible change from a full range system to a 'subs on aux' system with channel aux send at unity. You shouldn't have to treat your channel equing any differently than mixing in full range. It isn't about having more steps to do. It is about having less to do! In most "Band" set-ups and sound, it is easier, and quicker to dial that sub aux when you only have a few instruments that you want to go to your subs vs. having to run a high-pass on 20 other channels to get them out of the sub bandwidth. This also has added benefit to your amps, being that they have to work less when you don't have all the summated noise floor that every channel ads to your outputs. The sub drivers will also become tighter if freed up from having to try to reproduce sounds from the entire mix, just like the example of the pre-fader aux send that is missed on your source music channel, you will still be able to recognize a song due to the whole stereo mix of the source channel. "if you send it there, it will try to produce it", best option is to only send what you want to exploit that frequency band, i.e. kick drum, floor tom/low tom, Bass guit, keys, and other instruments that live in that bandwidth, your overheads, for example, should be as far away from your sub bandwidth as possible, even if high-passed. I also do that to front-fills when we are playing a smaller venue. It is only the channels that get lost over the stage volume, i.e. vocals, acoustic instruments, etc, that I feed into front fills. This only a cursory explanation of why I use subs on aux and not matrix or mono. I am happy to get more in-depth on this, if interested, but this comment is already turning into a book.
For me I run aux fed subs. I set the subs up so they are roughly the same volume as my tops and so I can have as much of an even frequency response across my PA. Once i've done that I only send things to the sub at unity and then forget about it (and also link the PA master LR with aux/mono. I use the aux feed as more of an on / off switch rather than a 'how loud I want the bass' switch. I like this as it acts as an immediate high pass and saves more energy for things that are routed to the subs. I do agree you can get caught up in thinking about routing more than actually mixing the channel but for me its a 'set and forget'.
I think it all comes down to approach, coming from a sound engineer background a LR mix makes more sense. It's how I've always mixed at venues and it's worked fine to date. If people prefer aux fed subs, all the power to them. I don't believe there's one better way over another, if you can make it work, you made it work. The crowd don't know, they're not sitting there like "can you hear this A1 isnt using aux fed subs!!".
Great thoughts. Related to #4 I would also add that when designing systems for permanent installs like churches, schools, community theater and similar venues where you will have a wide range of mix engineers, including volunteers, using the matrix approach and a single fader will be much more user friendly and keep them from getting lost. You set the system up properly and turn over the system with confidence.
I try to maintain an open mind. I do typically run my subs aux style. However, I do like the concept of this approach and the benefits that could come out of it with regard to tonality, TF translation and stream balance. I might have to try it out at my venue! Can't knock it till ya try it! If it doesn't seem to work, it's easy enough to switch back. Keeps ya fresh!
This is what I'm thingking too. If a reference music can go to a PA without mudding the vocals that means we can do it in live also, its only the matter on how to use your eq on your channel.
Question here. I've been learning about aux subs and watched this to combat what I've been learning. Mixing at a smaller church. 50x80 room with overflow rooms open to main room (zone 2) I have a external PA processor with only 2 inputs. How do I control different zones levels and subs on the console but still use the EV DC-one processor. You use 1&2. Left/Right. 3. front fills (in my case overflow zone 2) 4. subs. with matrices, but i only have 2 inputs on my processor. Would I bypass the processor to do this and just go straight to amps? Or the processing on the matrices would output the stereo bus to the processor post fader with the sub fader affecting the stereo output? I have new gear on the way and i want to understand this stuff before i route the new console.
this makes perfect sense to me. never stop challenging norms . it's how we grow. there will always be people who say outside ideas are invalid. even f they eventually are, trying new ideas is how we grow. i love this channel. one of the most eloquent educators out there. i wish i had your savvy at your age but i'm a late bloomer. by the time you are my age you will be top notch, no doubt.
I use the main L/R output for my subs. I can take R for the tops and L for the subs after coming out of crossover with the high and low. I use the PAN knob on the channel strip to assign each things at channel level to the subs. For example, for kickdrum I PAN hard left and also compliment with the EQ low knob on the channel strip. For vocals , I PAN right and also use the EQ on the Channel strip to achieve a balance for the low ends and high properties of vocals . It works perfectly for me in house of worship and all applications
I think there's a general misunderstanding as to the intention of aux fed subs. It was never intended to use as a volume control for the sub freqs of an input. All the sends & the aux master should be set to nominal. It was intended to simply keep the subs as clean as possible by not assigning channels that you don't want in the subs which also reduces ambient low end on stage from leaking back through those mics into the subs. With digital consoles these days you have a lot more at your disposal to control the low end on an input as needed. That was not always the case. It's arguable as to which method get's you there quicker. One thing for sure, there's a lot of misunderstanding & therefore bad use. Anytime you adjust these faders off nominal you're changing the crossover point...
Great point here, Tim. Yes, before I switched to either feeding just my LR mix or running subs on a matrix I ran my aux fed subs that same way. Everything sent at unity. If you do end up running into feedback issues with certain sources in your subs, that is certainly helpful.
Thanks for your thoughts. I see one issue with sending a copy of your entire mix to the subs and that is that in the case of vocals you are right in that a recording doesn't have the big bottom on the vocals that many people seem to leave in them in live situations but I think we need to explore why that is a little more. Yes, some folks have not quite understood why we commonly don't use much bottom end in vocals on recordings. That is true but the thing that some people don't understand is that the best way to achieve any specific sound especially in a recording is at the source. In the best recordings the vocalists are a good distance from the mic thereby creating far less proximity effect than with mics on a stage. Heck more often than not even lectern mics are closer to the face of an orator than a common studio vocal set up. Also something to note is that lectern mics are commonly hyper or super cardioid designs because they need the off axis rejection but with that the trade off is that they suffer from excessive proximity effect. Some consoles offer a -24db/oct cut but with that if you look at the curve you will note that above the cut frequency they also ten to boost information which is most commonly not a desirable effect either. While using the crossover as a low cut is not going to fix your recording it can at least make the house mix more usable when using substandard quality mics (we commonly record with mics costing in excess of $5K. Stage vocal mics are commonly some of the cheapest mics in the box. While the cost of a given technology is not a direct correlation to sonic quality it does in fact factor in.) An alternate to correct for the record feed which I mostly do from stereo matrixes also is to run the vocal through a buss that is doing some of the global corrections for the vocals/ for example commonly engineers spec the same mic for all of the vocalists who are performing together. There are some good reasons for that for those who don't understand but that is another topic altogether. Suffice it to say that undoing the "58 curve" is something you can do as a global setting on a subgroup while using your channel eq to fix specific issues for the various singers as well as some consoles allow you to low cut in both sections or at least "low shelf" the bottom. Also inserted eq can be your friend there as well.
Great thoughts here! Thank you for sharing. That all makes a lot of sense and I totally agree that the proximity effect becomes much more of a bear in live sound. Yes, I a great "compromise" approach is to have a Band subgroup that passes through to the LR unaffected then a Vocals subgroup that has any needed low end shaping so you don't have too much rumble. I can see how that's especially effective if you're mixing monitors from FOH and the lead vocalist doesn't want to hear their voice too kneecapped on the low end if you don't want any excess rumble in the PA.
Aux fed subs are appropriate for hiphop and DJ-centric venues. In those situations you often ride the gain on the subs to suit each particular track or performer, as well as punch up the energy in the room. For live bands, however, it's better to use FOH speaker management via well-tuned external crossovers. That way your master fader controls everything as it should, and there's no need to complicate things with a layer of matrix outputs.
@Bogdan Chepurny - For a parallel livestream mix, I run a separate stereo submix that is routed post-fader, and set all faders in the active channels in the livestream at 0db. That way, I can choose which FOH channels are also routed to the livestream, and the livestream channels track the FOH channel faders. I don't use compression on FOH, but have found that livestreams need extra compression to maintain a more consistent volume level.
Try a multi-band comp (Like C6) or a Dynamic EQ (F6). I do this for every show with pre-recorded source tracks as the main source of music. Most of the time, the source material is mixed over emphasizing the lows and highs. If no multi-comp or dynamic eq is available to you, you can use an analog compressor with a sweepable key frequency. If you insert it onto you sub bus, it should give you the control that you are trying to achieve.
I’ve run subs in an aux for so long. I’m used to some of the “oddities” like walk in music and things that are hitting those subs differently. BUT. I have been watching your stuff and I am trying the LR to Matrix mixing for some clients to see how it works. I’ve got a room to test soon and I’m rebuilding their X32 for matrix feed and I will try the subs this way and A/B it to see how it works. I also see the benefit from a mixing standpoint. You just mix faders at the end of the day. All those tweaks should represent a whole system that sounds good. Plus it cleans up your LR mix for reference and review. When I think about training new people to mix, I can totally see this being a great choice. It’s more wholistic!
Michael, I have done this both ways. On very large shows I have done the Left/Right to 4 matrixes, Left/Right/Sub/Fill. We always do it in that order. We do get the request to set it up Left/Right/Sub/Fill for many of the artist we support where we are doing a Aux for sub and Matrix for fill. I myself prefer the way that you suggest and as you said if we need to do a live feed for recording, we can just simply pick another Matrix and send it to the live record feed. We did this at a corp show last week. As I said, I prefer to do my feeds as you suggest, however I have clients who prefer the aux method and when they are paying the bills we do as they wish. Nice video.
Thanks for sharing, Bill! Yes, totally agree that your system setup must be flexible enough to accommodate other engineers who run their mixes with an aux send as well as fills.
I'm the engineer at a relatively well known venue and the only touring engineers who show up and fiddle with some alternative to aux fed subs are younger than 40 and haven't been doing it for very long. On the flip side, every single 40+ engineer uses aux fed subs. The only real difference at the end of the day is that the younger engineers are all stressed out and having a bad time because they've inevitably overcomplicated things in an attempt to... not do it the way that's worked for decades? All the routing tomfoolery in the world won't make up for a fundamentally bad mix, and typically these engineers end up wasting valuable time when I hand them Left + Right + Sub drive lines that just go straight to the amp rack and it doesn't jive with their Proprietary Mix Magic. Of course, to each their own and there are myriad ways to run sound, but the older guys aren't doing it because they're luddites, they're doing it because it's simple and effective.
I'm 1000% with you that this pervasively overcomplicated mix trend, especially with young engineers, is debilitating and unhelpful. I've seen too many talented young folks get so bogged down in miles long Waves channel strips on the hi hat that they forget to ride the lead guitar for the solo. Rant over : ) A good mix is a good mix, full stop. I'm not trying to stir the pot and say that these veteran engineers can't get great results out of an aux fed rig, I'm just saying with my workflow I prefer using matrices and here's why. That's all. If I'm system engineering for a FOH mixer who wants to send LR+Sub, they're more than welcome to.
@@jakestanbro959 I just ran sound for a band at a large festival and several of the other touring engineers kept complaining about how the sound system wasn't tuned properly and there was too much low end. Turns out, they were all using subs on a matrix. They were complaining about an L'Acoustics line array sounding bad while making an active choice to remove their ability to simply turn down the subs with one fader.
There are a lot of considerations when it comes to routing signal through your console. It not only depends on the capabilities of the console (some can't route groups to auxes and some can't route inputs direct to a matrix, or some don't have matrices), it also depends on what the PA is, how it is setup physically, and what system processing is in place. My first preference is to use group-fed subs so I don't have to worry about getting pre-post incorrect. The channel processing is still full range so my LR buss is still getting all the same low-end information which is getting recorded. It's up to my external system processor to handle the crossover between subs and mains. In some cases, if you have flown mains and ground subs, you may not wish to high-pass the mains anyway. In that case, the subs are definitely just icing on the cake and need to be treated more alike an LFE. If I really need the subs to carry the whole PA, then maybe the approach changes. I strongly agree that variable sends to subs is a straight up terrible idea. I'd still use an aux in a pinch but it would only ever be unity sends and let the system tech do his thing (I'm also primarily a system tech, so there's that). On an M7CL, you can't have groups, only "fixed auxes" which is the same thing anyway. I sort of don't care about the transfer function reasoning - I think you should mix with your ears, not your eyes. I've never mixed live with a constant TF and don't feel the need to. I still argue that with group-fed subs, the TF won't be completely wonky, it'll just appear to have a low-shelf boost because, again, your LR buss still has a copy of the same information as the subwoofer group. Lastly, I strongly believe that high-pass alone is insufficient for low-end management. The HPF frequency is the 3dB down-point and the roll off is still a curve. A 4th order LR filter at 100 Hz is only 6dB down at around 80Hz. For every non-high-passed mic on stage, you're gaining 3dB. If every mic on stage is only high-passed at 100Hz, you've now added enough low-end energy back into the system to fight your crossover or high-pass frequency set points. It's still totally possible to get an 80Hz or 100Hz ring in this setup. You got the point about a studio track through a PA incorrect. Once a 2-track is printed, the high-pass filters used on each channel become printed and there are no open mics. Microphones feed back, not speakers. Everything in the track will go to your subs, yes, but that's only if the information is in the track and that's why we use a system processor to low-pass the subs.
All great points here. Like you've mentioned, the routing and processing available to you on each gig will dictate how flexible the system can be. I've personally found the high pass filter alone on my live music gigs to be sufficient, but on this most recent corporate gig of mine when I ran my LR Bus as the source for all speaker destinations I had to do more LF ring out on my lav group than I usually do since the PA tilt had a significant LF tilt in the PA because there was also a live band. So there the HPF alone didn't work, which proves your point. All things considered, a variable aux alone I don't think is a good idea, but I'm starting to change my tune a bit about strictly sending the LR mix into the processor and having the processor ONLY manage the LF. I'm actually in the middle of rebuilding some of my corporate console file templates and will likely be sticking with LRSF and taking my lavs, handhelds, and podium groups out of the subs. I appreciate your feedback.
watch Dave Rats video on Aux and sub sends, you'll see why its a better method of mixing live audio and keeping unwanted frequencies that filters will not completely remove. I've done both depending on who's system Im using and will always use an aux send for subs if I have the choice. I politely disagre with what you are saying.
6:17 If you Hi-Pass the Mains and Low Pass the Auxiliary Send that feeds the Sub at an appropriate frequency, 80Hz for example, and then send your reference track to the Sub on that Aux, no vocals should be reaching the subwoofer.
That's correct, but that's assuming that the subwoofer downstream of the aux send has no other processing after your console. If it's an active subwoofer, putting a high and low pass on the aux will double up on the crossover processing and narrow the sub's bandwidth unnecessarily.
@@MichaelCurtisAudio Hi pass the Mains, low pass the Aux that feeds the Sub. If the Sub is already being low passed at the sub itself? Then, don't low pass it at the Sub Aux, or vice versa... Or choose which low pass you think sounds better. Easy work around if that concerns you..
Then we're right back at square one - running no LPF on the aux send means we're still sending a full range music track to the sub, then letting the sub itself do the processing.
@@nodaysback1 That would still double up the low pass filter on the subs. I promise I'm not trying to be confrontational, just having a hard time following the logic.
When I first heard of the subs on aux idea, I had the same thoughts as you are expressing here. Thanks for confirming what I've been thinking about this for some time. Good video.
I still just use a crossover lol. I will explore this method for sure. I've tried aux fed subs and just went back to an external crossover because I was constantly "balancing" the system. This would eliminate that👍 Oh, and I always MUTE the walk-in music channels right after I fade them out now. I had the same thing happen lol Great video! Cheers
If you have a multi-speaker system, you will still need to use a crossover, whether it is passive or active. Now-a-days, it is mostly programmable amps that take care of crossover functions. If you are still running analog "dumb" amplifiers, you will need an active crossover to run your speakers correctly. You said "I've tried aux fed subs and just went back to an external crossover because I was constantly "balancing" the system." This is kinda confusing. Without the external crossover, subs on aux doesn't work in the first place. Unless you are saying that you do something like low-passing the buhjesus out of your sub bus, and then send that signal straight to your amps. That is the only other way that I can see this happening, and that is just silly talk, lol. Shout back if I confused you, that ability seems to come naturally to me, lol.
For me, it boils down to several things: 1. What console am I working with? 2. How many outputs do I need and how many are left? 3. What type of event am I mixing for? 4. So I have any external processing control for the PA? All of that is going to influence whether I use aux-fed subs or not.
Thanks for the video but how to propertly fed subs when I don't have any matrix possiblity right on the mixing console? Is there any other way than aux fed subs or using external crosover processor?
people seem to miss the point of aux fed subs ..the point is you send only sound sources that has sub frequencies you want to the aux .so like plufs on vocals is not a problem .don't need subs for snares , rides ,crashes ,hi toms splash Banjos and ,Vocals ..there mics will only pick up wind and handling noises hi pass filter do not stop every thing
I might be wrong, but I don't think @MichaelCurtisAudio misunderstood the idea, he just said that modern consoles offer variable HPF and low shelf/peak cuts on every channel, and therefore this point is moot. IMO, if you are used to mixing in the studio on full-range speakers, the idea of mixing full-range on a PA just makes sense.
1A/3/4. I would best describe as make your life easy by not doubling the mental load of keeping track of where your decisions are. Similar to using a compressor - volume = volume out with the make up gain. 1B. I don't really buy the broadcast limitations. If you are using the FOH mix to feed broadcast you are already making a sub par compromise & most of the playback devices won't really produce the low end anyway. If you want to include the sub in broadcast then you can use a matrix to combine it with the LR. Ideally it should be a complete separate mix & if you have the budge a passive split (or like the Pro 2 with completely separate pres in the remote i/o). 1C. Yep shelf that low end away on everything that hasn't got bottom end you need.
I hate aux fed subs. I learned on 4 way live mono. With a crossover. Club system I work on mostly we have two systems prosessers Yed into the amps. One for the DJ on for bands. I get sent out on many systems with aux fed subs and it is one more thing to think about. I prefer a system proscessor or X over. I am not that savvy on smmart. I would like to hear about your setup on the mono bus for smmart. These days you can’t burn an aux for subs when everyone wants stereo in ears or 10 separated mixes. I found what you said very interesting
I’ve seen some recordings missing kick drums because the mix engineer simply decided to run the kick only to the sub aux. Most churches and bands have volunteers, and probably someone from the band is doing the mix. Having less aux to worry about is great. A good and leveled PA is much better than mixing a separate aux.
Two things: first is something I discovered recently, second is something you confirmed. 1. Adding low end shelf to the sub channel isn’t necessarily a good idea, due to affecting the crossover on the parametric eq (so far this is an observation) 2. Continuing 1, eq from input channels instead of thinking it’s a global issue. That changed the way tracks sound, as well as overall mix. I use the Center channel on M32, factoring in what I do or don’t need in the mains. This works 99.9% of the time, especially since there’s a dedicated rotary knob in on the penthouse section. Even the TF series suggests a center channel via Sub out, yet I do like having the option of stereo subs depending. I’ve since then summed both sides to mono at my Sunday setup, but hasn’t caused any issues so far.
What about Headroom . . . Sub Frequencies eat up a lot of Headroom on your Stereo Bus/MixL/R ? Also thought you would mention how Aux fed Subs change the X Over Frequency due to variable levels. Lastly there is the question of Low End Contour on your whole system. Aux fed sub seems to give you control of that easier than with L/R and EQ. When a gr8 Mix Engineer is Mixing A Good Band , L/R Stereo all good . . . . When the source is varied between different styles of music , especially playback / edm , how do you get around to control your Sub , considering different genres require different LFE contours ie. +3 , +6 , +9 dB. Thank You for sharing your knowledge and videos. They are amazing. Learning a lot.
Hey, Mandla. Great questions. A subwoofer will filter out unnecessary frequency content before trying to reproduce the waveform. So, the difference between a mix that only has kick and bass guitar in vs a full mix once bandlimited to the sub range is incredibly similar. I'm not too concerned with the crossover changing unless the mains and subs are coupled together. A mix engineer should just worry about the quality of their mix leaving the desk. The systems engineer can then give them the desired response of the system easily with a low shelf on the rig, no problem. Most large format mains speakers, like L-Acoustics K1 for example, go down to 31Hz themselves. So, if subs are on an aux and the engineer asks for less sub, you're taking out the subwoofer, but there's still PLENTY of low end coming from the mains. So, feeding the entire rig LR means you can apply a low shelf across the whole thing and shape the tonality in one simple place.
Good points, well made. But how do you respond to those who would say that a typical mixer channel strip HPF doesn't have sufficient rejection to keep microphone handling noise and other unmusical LF content out of your subs? (I've heard it argued that you would need an ultra-steep HPF slope to properly eliminate the unwanted microphone LF, but even if you had such a sharp HPF available, you would risk excessive group delay distortion near the passband edge.)
Aux fed subs makes a lot of sense to me. Other than kick drum bass guitar keyboards maybe floor Tom you don't need anything else in your subwoofers. I cross over my subwoofers at 90 Hz. And actually I do not feed them off and auxiliary. I use the Center channel out of my M32. so if I want to ride up the master well that Center channel is right there next to it so I can ride them up and down together which I never do anyway. I started my Sound reinforcement company in 1980 and I forget when I started feeding the subwoofers off the auxiliary, but it was a game changer for me. As far as streaming feeds or other feeds, it's really not a big deal as you make it sound.
To your first example… Reason I use subs in separate bus is because vocals in studio or instruments are in a perfect environment. Vibration and wind free. A HPF won’t fix that in a chaotic live set.
At my regular gig, I use an m32 and the gain on my PA never changes, so I run everything to main L/R then use 3 matrix, one for L, one for R and a mono sub through out 14, 15 and 16, and 9 times out of 10, my sub matrix will be at -20 and rarely ever moves
Re X32 Buss to Aux (8:32): Yes you can route a Buss to an Aux, or any other channel, (and therefore also route a Bus to another Bus, via a Channel) I agree with the Subs (indeed all the PA) on Matrix after the LR, for simplicity of control and trouble shooting. After all, having spent the time (and money if you have bought Smart) to get a good even frequency response in the venue, would you mess with the PA balance (subs level) during the show rather than ‘tuning’ the band sound with Ch or Group Eq. Thanks for all your brilliant tutorials, especially on cardiod Subs, going to be experimenting with this next time I can get into the venue on a non show day.
Ah yes, totally forgot I can put a bus on a channel and do routing that way. Thanks for the reminder there. I'm glad you've found my videos helpful! Let me know how the cardioid setup goes for you.
Holy cow thank you for addressing the elephant in the room. I keep seeing these posts from big name mix engineers (Dave Rat and others) talking about using aux fed subs. Im not gonna say these guys arent mixing killer shows. But i dont think that way. I come more from a studio mixing background, and you NAILED almost all the concerns ive had with aux fed subs for live show mixing. I will add one here- processing done on your master LR buss is weird and skewed when the low end is on a separate bus. I like to mix with a multiband compressor and limiter on my master buss. If my low end isnt hitting that, what am I supposed to do create another compressor just for the sub aux???? Its just way too much to have to think about. I want my PA sounding like I want it to sound, then mix INTO it. If you have to be adjusting overall low end levels on the fly, you havent got your PA tuned well. If my kick drum isnt hitting at 50 hz the way I expect, I know the mic has either been bumped and is off kilter, or something else is going on. Heres another example- last church I mixed at for a while had aux fed subs and it was a constant hassle. I could NEVER get the top end bite i needed from the kick drum. Same mic ive used for years. Kit was tuned well. It had to do with the way they tuned the PA, the crossovers and DSP happening inside the amps. I was boosting 8db at 3.5khz and still didnt have the top end I needed. After a little while i realized the kick wasnt patched to the top AT ALL. Sigh..... got that patched, things got a bit better but it was still a constant battle to get a simple kick sounding the way I wanted. If your PA is tuned well, you should be able to get dynamite results without aux fed subs. Use high pass filters as needed to prevent unneeded low end from hitting your subs. After all this time I just still dont understand the need for aux fed subs.
Thanks for your feedback here and I'm glad the points resonate! One thing you mentioned that I wished I had thrown in as well as how it prevents any master bus processing. The only time I find myself using aux fed subs is on corporate gigs if the subs are very close to the stage and I have a lot of lav mics. If someone hits their chest I don't want the "BOOM" to be so accentuated. Other than that, matrix fed or just letting the processor handle it all is the way to go : )
Great video! I would suggest to handle the proximity effect of the vocals in a more "elegant" way, to use a dynamic EQ or multiband compressor on your vocal group. This way you only trim down those muddy frequencies when proximity effect comes in play. (I do understand this tool is not always available in every mixer)
When I encounter a system that's set up with aux-fed subs, I leave it that way, but I set the levels "at unity", so the system is still flat, I'm just taking advantage of the "tighter" high pass filtration. (Boosting the sub level on a channel seldom gives me the result I want, so I don't bother if I am configuring the system.)
I run my my subs in aux for flexibility. I think it is very possible to set up aux fed subs in a way that negate pretty much all of the downsides you talk about. But it is good to be aware of the drawbacks of any mixing practices you use. I personally believe that if you are intentional, careful and understand the limitations aux fed is fine. I don't think your take is particularly convincing. The audio isn't ever really a coherent field for the average listener. Having discreet control as a mixer is important, there's no reason to limit us to just using EQ, compression, ect. Not having certain instruments go to your subs at all creates more headroom than just using high pass filter.
Hi Michael, First of all, thanks for your awesome videos. They share a wealth of information and straightforward approaches. Wished I found your channel way before!. I pretty much agree on your aux for subs philosophy. Especially when you have system processors that make all the division and parameters from within by just simply feeding a LR signal (like old 2-5 ways analog x-overs). Just wanted to share that I use a Yamaha TF5 which has a Sub fader. It conveniently fits to the system processor which has L+R+ Sub inputs. Depending on the gig, I use the mixer Sub fader unprocessed or LPF it around 90Hz. In addition, when needed, I can bring it up or down to get an instant tonal balance at the FOH if any sudden environmental/unforeseen issues might happen. Streaming or recording are via Stereo Matrix fed from the L+R (all low end instruments like kick, bass, an others are always routed to LR main). Thanks! Abdel
Thanks for the input here, Abdel. Glad you've found my videos helpful! Yes, having your subs on a Matrix or its use Master bus is super helpful, especially it's a new rig or your environment might change. The TF5 is a neat little desk.
While the SQ series can send groups to aux, it doesn't make sense with regard to the arguments pro aux-fed subs. Because would not send the drum group to aux, but only the kick drum. However, especially on small venues, you might want to delay the drum group to align PA drum output with direct acoustic drum sound. Which would work with aux-fed subs, however at a much higher level of complexity. You'd have at least two places to visit in the console to change the delay.
I like to run aux fed subs because, i use 2x dual 18 subs in the middle of the stage, then i have 2x single 15/18 subs on the side with my Array tops ontop for my LR mix. Then i send the outside mic (for low-end only) of the kickdrum to the dual subs(aux fed) and the inside of kickdrum mic with a low cut of 100hz so i get mostly attack to the LR system. then bass guitar and the rest of the mix also to the LR speakers. Is this an effective way to get separation of kick and bass guitar, low-end spread and a cleaner sound? what issues may occur?
Although I like your creativity, I think this overcomplicates things a little bit. Your technique borrows some elements from mixing on a front-field immersive rig. Although immersive mixing let's you physically separate out where audio sources are coming from, every major manufacturer I'm aware of with an immersive platform still recommends all low frequency heavy sources come from the same center sub cluster. You've probably heard of Dave Rat double micing sources and panning them out left/right to get separation. I know you're not double micing EVERY source, but it is common to have an In and Out mic on the kick like you're doing. What I think is worth investigating is how much actual correlation is occurring between those two mics. You can only mitigate comb filtering when two sources arriving at the same point are either decorrelated OR greater than 10dB in level from each other. Given that, I'd run some tests to see if the kick In and kick Out mic are actually all that "different". Hopefully that makes sense!
@@MichaelCurtisAudio Thank you Michael. your content is epic. I still have some questions, Is it not preferable to separate the kick and bass guitar's with frequency like this, kick drum focus is 50hz to 100hz Bass guitar low cut till 90hz with focus on 90hz to 400hz. This way you don't need the bass guitar going to the centre subs because you have made space for it in the LR mix just above the kickdrum frequency, even better separation? Thank you for your feedback
That's definitely a school of thought when it comes to "carving out space" in your mix. Although this makes intuitive sense, I as a bass player wouldn't want the bottom octave of my instrument to be missing : ) I think there are other ways to make sure both the kick and bass can live in the same space without clouding the other. That largely comes down to the arrangement and players first, though.
For me, it’s all about the situation I’m mixing for. When I’m doing talking heads, I prefer aux sent subs because I don’t want to roll off at 160. I want to roll off at ~100 because for intelligibility for talking heads, 100-160 has a very small sliver of frequency that helps make voice fuller. It’s nuanced, but it matters. If I’m rolling off at 160, I can’t get that nuanced frequency in my voice. I use a K-Array system at one venue and if you don’t separate the subs from the top, the proximity effect on the podium is uncontrollable unless you start rolling off and using multi-band compression on the sub to take it. Instead, I simply don’t sent the voice to the subs but send everything else to the full system. This eliminates many of the headaches but the pre-function music to subs…oof. Been there. Not fun. But still, at the end of the day, does it sound good and is the client happy? That all that matters. For me doing corporate talking heads with a system where I can delineate what goes to subs vs tops, my talking heads need to stay separate in order to tame the low end beast.
i think this is a matter of "simple but limited" or "advanced but cumbersome". i run our subs aux-fed and i like to run our bass guitar exclusively to the subs. ive found that it gives a MUCH better spatial separation between the instruments, and it gives me _more_ room to mix the other instruments. i'd heard from Dave Rat's philosophy that sound comes from different places, so thats what im doing. (i let tops handle sub frequencies with an EQ. theres not a lot if theres no bass guitar) i will admit though, like you said in the video, eliminating variables helps me have a clearer head for mixing. i run a bit of kick drum to the subs, and it bothers me a lot having to juggle that with the bass, and with the whole PA. not to mention that whatever channel i run to the subs is always a different configuration to a purely FOH out channel which causes a hectic confusion sometimes. i will try a linked-sub system again this sunday, no aux and see how it goes. i think theres a lot to say on this topic, very interesting. and very interesting video too!
I am running in the next 18 for local shows since it does not have any matrixes. How would you suggest that I control the lower end not using aux fed subs?
Mono to sub fan here. I like your theory as it forces you to make good EQ decisions, however it does not account for most consoles having only one HP filter slope on individual channels that might be less steep than what you’d want going to your subs.
Great video. I don’t disagree, but do have a counterpoint. With live PAs, we generally have an exaggerated sub to main ratio. Some level of a haystack in the bass frequencies. With aux fed subs, the mix engineer is able to prevent vocal mics from going to the subs at all. Without aux fed subs, the only tool is the high pass filter. Do you find yourself high passing at a higher frequency to be more effective in the sub region, when the subs are boosted 6-10db above the mains? If more aggressive on the HPF, that would affect other mixes for streams, etc. Would love to hear your thoughts…
Hi Phillip that's a good point. I had a vocal with 85hz high pass filter. But I noticed it was still sending a bit of low frequency energy to the subs even though my xover freq was 80hz. I thought it had to do with a slope of the high pass filter. Anyway, that made me almost force me to use aux fed subs. Yes, I'd too like to hear your thoughts on this.
Great counterpoint here, Phillip! Glad you liked the video. As much as it feels like vocals in the subs is the issue, in my own systems (without floor wedges) I have trouble with vocal feedback in the 200-600Hz range, which sits squarely in the custody of the mains. The highest crossover frequency I use for subs for most rigs is 100Hz, which would be a low G for a bass singer (and the open G string on a bass guitar). There's of course a slope downwards in level or frequency for the subs after that, but they're usually more than 10dB down by 200Hz. I feel like the bigger issue is too big of a tilt in the LF on the MAINS. If I'm running a show that has both a big dialogue component AND a big a band component, I'll have the pink shift/LF shaping on the PA geared to sound great for the band, then use a low shelf to shape low end for my Lav/HH bus. My system target curve shoots for a flat PA from 1kHz to 10kHz, then some tapered HF dropoff after that as you move from front row to back row. For LF shaping, there's a +9dB rise from 1kHz down to 100Hz, then it's flat from 100Hz down to 31Hz. So, it's PA systems that have a much bigger LF lift down towards the subs that I think pose a bigger issue. Also, on BIG big PA systems the mains easily get to 60Hz. So, even if you did take your vocals out of the subs there, you've still got a significant amount of LF power coming from just your mains. If you still want to make sure vocals never hit the subs, I'd run a Band and Vox subgroup, then route accordingly to matrices. That just makes it harder to do any overall PA tonal shaping without duplicating processing. As far as vocal processing and EQ, these days I'm running HPF at 160Hz to start, then having a low shelf at 500Hz and a high shelf at 2kHz. These high and low shelves act as a "tilt EQ" together. If too much proximity effect, bring down the low shelf. If not enough top end to cut through, boost the high shelf. Then I have one parametric filter sitting at 400Hz to cut any mud. Hope this helps!
@@MichaelCurtisAudioAlso, think of the harmonic's the subs unavoidable are creating ... there is actually more distortion in a "punchy" sub, so even if you have a 4th order crossover at 90 hz vill 120 hz and 180 hz come creeping in as byproducts.
There is another point to be made about the cumulative effekt of having a wast number of inputs lowcutted at the same frequency, the ripple or bump just at cut off - is pronounced
I engineer large corporate shows mainly. I usually run subs off a fixed bus, not an aux for corporate. The system is tuned full range, with the mains HPF to match the subs. The difference is that I only put things in the sub bus that I want there, and these are mainly video rolls/walkups/VOG/Playback. The channel counts on these shows are usually a whole bunch of RF lav/headset/handheld mics and fewer playback sources. I do still HPF these microphones but I only have to worry about that in regard to the main PA, because they do not go to the subs at all. With this format I can't add more/less sub per channel, either something is full range or in the mains only. If I am mixing music I will probably make the sub group into a variable [aux], but I will still tune the room with the aux at 0db so that is the absolute and 'correct' starting point for anything being fed into the subs. This just adds a little more freedom on something like a kick drum, to add that 'live thump' that is not going to translate well in a record mix anyway. I do like to use my L/R to feed the Matrices, which is counter to a lot of corporate guys who go group to matrix and use the L/R bus for record feeds. I like to be able to do a few system wide eq moves on the master L/R. But this can occasionally get you in trouble for corporate depending on how much of a matrix hog you are, for instance maybe you put out a lobby speaker or ran a feed into an audio embedder and made it a matrix... then the client doesn't want walk-in music in that feed and you basically have to rebuild that feed. I now do an additional feed into the matrices that I call 'royalty', and I will put my walk-in/out music through that feed. If it isn't wanted in some matrix then I can just cut it from the matrix. Sometimes there are additional feeds to the matrices as well.
HPF and for that matter LPF are my fundamental tools for building a mix. They often are the basis of my equalization to the point I often need far less time getting a sound on a given channel once I’ve filtered. I can’t imagine why anyone would object to this. Most of my music mixing is for broadcast or release. I know the frequencies of musical tones and use that to narrow every channel as much as is possible. In symphonic spot mics, this is done without question. Ditto an electric band perhaps even more so. If working in surround, my Sub is simply the speaker handling the lowest octave or two. I have never been happy with aux fed subs and leave them off if they are present. You are preaching to the choir here about ‘aux mixing’. A recipe for disaster and a tail-chasing exercise - I’ve never needed either.
Hi Michael, I’d love to know if you still feel the same for corporate work. I usually do exactly this for music work, but for corporate I often do buses of different inputs (lecturn, lavs etc) straight to my various matrices to allow me to slightly shade down the lecturn in front fills for example to give me a tiny bit more headroom for the rest of the space. Thoughts?
i might agree with most of this if other people use the mixer, or if your live streaming off same mixer during live show. But disagree with most of this on my own mixer. As far as not having to think of where any signal is going during the show. I have that ll mapped in my head, so its easy decision in my head to decide if i send more kick or tom to the aux or boost the EQ. Its also way easier to tame the low end of a bass guitar by reducing the send to the sub vs EQing the lows out. Another huge plus is if you play outside in the wind. Its a lot easier to keep wind noise out of the subs, if your not sending most of your microphones to the subs.In fact, Iuse Matrices for each output, Left/Right Main, Center, Infill or Outfill, and 2 separate for subs. I have full control of what instruments or mics go into each matrix. Sometimes I will even send Kick Drum to a center sub, and Bass guitar and floor toms to the outer subs where I cant center cluster all the subs.
Thanks for this excellent explaination of your preference. If im mixing multiple different sources. Ie headset mics, HH mics, close instrument mic, rifle mics etc. I set the console inp-grp-mtx. So bypassing the stereo bus. (Hear me out) So if I have big loud brass section who are loud onstage i can "dip" the send from the group to the front fill mtx. It makes the setup a little more complex but gives you a chance of evening out acousticly loud instruments. The default is grp send is unity so it makes it possible to do a full consistsnt sound check. So i only use this to attenuate levels never increase them. I think im going to try your way the next time though! great vid, keep up this great content
The matrix sits downstream of the LR Bus and inherits its signal and processing. The mono bus is a separate signal path. So, if you applied mix bus compression on your LR mix the same processing would not apply to your Mono bus.
@@maizesoft Yes, I'm well aware of this video. Dave Rat has some good points, but I feel like it's a non-issue with most vocal mics. An SM58 already had a fairly steep LF dropoff below 160Hz and I'm usually high passing at least that high due to the proximity effect. I'm usually able to do a cardioid configuration on my subs which keeps more LF off the stage. If I do need to get some specific sources out of the subs (lav mics, podium mic) I opt to matrix out my subgroups to the appropriate destinations vs using an aux for my subs.
I think it's only good for a big pro mixers or digital mixers, but for smaller mixer (like a Yamaha MGP16X or Beringer Xenyx XL2400) they doesn't have a matrix (a good one), so you must route subs from a Group, Aux, or mono(even Yamaha doesn't have a mono channel control)
I have tried this (matrix to sub) and aux or mix. Correct me if I’m wrong, sub send on a matrix; you are sending all content after L&R to the matrix. Are you creating a crossover? I mainly work in the corporate AV world.
Hey, Robert. Great question! Yes, all channels you want going to your full PA go to your LR mix, then that LR mix goes to your mains, subs, and fill systems matrices. I usually run matrix 1/2 as mains, 3 as front fills, and 4 as subs, then use more if i've got side hangs, delays, etc. You would apply the EQ, crossover, and time alignment processing on the matrices, so that when they acoustically sum in the space you get the results you want.
You are absolutely right! Modern films sound wrong. The sound is all boom and crunch. It doesn't sound natural. If you use a good processor it will sound real and right!
Very good video I'm using aux fed to fed my sub, but my livestreams sound weak but the room sound very good. Now where should I plug my subs, strait from the main speaker or else where.
Dave Rat just did a video on why he prefers the aux fed subs and I tend to agree with him although Pooch & Rabold have a video where they swear by a LR and no aux fed subs. I'm on the M32. Matrix 1 & 2 are Main LR like you said, high passed accordingly. I send only what I want hitting my subs to the M/C bus and then that goes to Matrix 3, low passed accordingly, LR 24 on all the Matrices. My fills live on Matrix 4. I like the idea of not sending any unintended non musical sounds to the subs. The HPF on a channel at 160 could still be producing some unwanted 80-120 Hz mud. Just my thoughts on it, still early on in my live sound career so I may change my mind. Great points to bring up!
@@MichaelCurtisAudio it depends on the gig. Going into venues, yes. Playing private parties/weddings where we bring our PA, it’s all happening at the desk.
@@drumskentala I would just make sure you're not "doubling up" on your processing with high and low pass filters for your mains and subs respectively. For instance, a QSC KW181 already has a low pass filter on it. Not saying that you could add another to reduce overlap, but just check how your mains would interact with those speakers first!
@@MichaelCurtisAudio Right on. Good guess I’m what I’m using for private events lol. I do find that in a lot of smaller room 90-120 Hz coming from the subs can be a bit overwhelming. Would you be wary of that because that could wind up killing too much frequency and it would make the whole rig out of balance and missing certain frequencies?
@@drumskentala If you feel that there's a buildup at 90-120Hz by all means use EQ to help tame it. I would just personally reach for a parametric filter first.
Grab your sub matrix input from the sub aux send and you’re good to go. It’s the FOH engineer’s choice to either use speaker management or dedicated sub feed, but understanding why you’re doing it one way or the other is equally important.
Referring to how you talked about using a matrix for your fills. What would be the benefit of using a matrix over using an aux in post? Wouldn’t an aux send in post have the same effect in terms of levels following the LR and getting the same mix?
Great question. With an aux I would not be able to send me Main LR to it as an input source. The LR on most desks can only flow "downstream" to a matrix. Furthermore, if I apply any master bus processing to main mix and the fills were on an aux, then my fill speakers wouldn't have my master bus processing.
I 5hibj many if us want our pieces featured in movies and stuff which is why it's mixed like sound track stuff. We use analog for the most part but post in digital but the end result is usually more sound track sound track which sounds better when it's played in a stadium as background music or something since it's already pre mixed plug and play.
Dave Rat would like a word... lol jokes aside.. all valid points, especially the part about it being uncorrelated with a stereo recording/stream/ etc. However theatre world where you have a million different speakers all over the place, correlation takes a bit of back seat when you have time to rehearse and program a console for 2 weeks and then aux fed subs are way more common. Great video as always!
@@MichaelCurtisAudioyeah ... Dave has a video and essentially he says noise is the reason he insists on aux fed subs ... Such as the noise that comes from gusts of air from instruments - say hi hat - that aren't designed to create low freq sounds. th-cam.com/video/hpFK1XOZuUg/w-d-xo.html. I don't understand enough about matrix mix to understand your approach ... But I'm up for the learning!
Would love to see a video on the use cases for a FOH reference mic. Generally, I understand it helps you get a sense for how your direct mix translates to the room, but are there specific things you are looking for in the signal? What is your preferred mic, and how do you decide where to place it?
When I use a mic at FOH it's to gauge SPL and also have a look at a few other graphs, mainly spectrogram and RTA. I use the dual-channel functionality of my analyzer during tuning, but single channel during show.
@@MichaelCurtisAudio Thanks for the response! This made it clear I need to develop a more robust metering system. During tuning, are you typically looking to achieve a "flat" response from your system? Or are there cases in which you may want the output transfer function to be nonlinear? I have usually taken this on a case-by-case basis (also primarily going by ear). I am wondering if I should get in the habit of staying flatter, especially in the balance between subs and mains. As you alluded to in this video, these types of nonlinearities can force you to think as both a system tech and mix engineer simultaneously.
@@nickwarren131 The "target curve" I end up using and staying with most often is from Michael Lawrence, a world class systems engineer. He uses it for the large scale systems he's tuning for musical performing acts. There's a -2dB drop off in high frequencies from 1kHz up to 16kHz. Think of it as a very broad shelf. Then for low end, starting at 300Hz, there's a fairly steep slope that goes +15dB up at 50Hz. So, the system is "flat-ish" from 300Hz on up, but then has a generous low end up to get some meat.
I came across this video because we decided to move from the Matrix sub feed and go to an Aux sub feed. I don't find that it will be any more complex than doing a stage monitor mix from the FOH console and we will be using less channels in the sub mix. I didn't understand your comments about the stream feed being affected. Are you using a matrix to feed your stream or an aux? Good video. I'll see how this works for us this weekend.
Thanks! My point about the stream feed is that if you're mixing subs on an aux that's yet another variable to your low end. So, it may feel "right" in the room, but since the low end is treated differently than the mains, it's hard to match that to your stream feed if you're pulling double duty.
Hi Michael, could you indicate a link or simulate two diferent size speakers SPL map (6" and 20", for example) at same frequency and intensity? This is for academical purposes. It would be very interesting to see how speaker size affects SPL using same conditions.
This may sound simplistic and insulting, but it's not meant to be. Sound is the movement of air. How much air you can move determines the amplitude (perceived volume) of your waveform. You're 20" speaker has to much mass to push and pull at 2000 cycles per second. Likewise, a 6" driver just doesn't have enough surface area to produce the same amplitude of wave at low frequencies. I hope that helped.
Michael, regarding your recent email where you stated that people said you were 'divisive and your tone was arrogant' in this video... and you're taking it down at midnight tonight. This is my response: "My husband and I just watched this so called divisive and arrogant video... what are you referring to, specifically?!? There was NO attitude from you. ... you sounded knowledgeable, concise and even gave us a heads-up we may ' vehemently ' disagree. Dude- It's YOUR CHANNEL , your content and rightfully your opinion. Please don't take down an 8-month-old video with NO dislikes and over 300 likes. If someone is causing you grief because they got hurt feeling... they can unsubscribe or turn it off. Respectfully, keep doing your thing. You weren't offensive at all! Don't worry so much about 10% of people who are never happy. Focus on the 90% who appreciate your work." Anna
Michael, while I might not agree with you about not using Aux fed subs, I love your channel and the knowledge you share with all of us. AND I 100% agree with Anna. It's your channel, do and say what you want. We'll either follow and learn, or we'll reject your ideas and move on. I for one, am here for the duration. Love your channel. Please keep up the awesome work you do and continue to share. The video you just posted a day or two ago about working that cooperate show, is priceless to me. Gave me SO MANY ideas to incorporate into my own prep work before a bigger show. Thank you! Thank you! Blessings for a wonderful, event filled 2023!!
It never even occurred to me to run the subs out an aux channel. I just use the sub out of my FOH EQ, and adjust the LF channels at the mixer as needed. I'll give your approach a try though.
In your example, Matrix 4 feeds the sub. Im assuming you are simply selecting LR main fader, choosing sends and raising Matrix 4 fader to unity. How is X32 summing that to mono from LR feed?
That's exactly it! You can also do it from the "sends" tab when you select your LR fader, then use the encoder on the bottom of the screen to send that to Matrix 4. The X32 automatically sums down a stereo source to mono when sending it to a mono destination.
Can you recommend an ideal setup for a DJ? I only have my mixing console with XLR outs to the amp. A lot of DJs are adding external mixers for more inputs and better control of the mics. They say it sounds better too. I'm wondering if thats really needed for better sub control?
I'm no acoustical engineer, and I'm the first to admit I'm no live mixing virtuoso--but riddle me this: what's the functional difference between your preferred method (feeding a subs matrix with the LR buss signal) and feeding a subs matrix with signals from groups? Sure, you miss out on whatever processing is on the LR buss, and you may need to make a delay compensation if you use latent processing. I'm already a fan of using drum and vocal busses, and if I made an "All Instruments" or "Video World/BGM" buss, couldn't I just send each of these busses to the subwoofers at -0dB, and have nearly the same result as your method? With, I might add, the added ability to remove any of these busses from the sub feed by muting its send? I think this "subs or no subs" method splits the difference nicely between the benefits of complete sub removal on problem signals and the downsides of aux-feeding that you describe in the video. And to preempt your inevitable question of why I would want to go about this bass-ackwards way: I'd like to be able to try something like your method in a venue which has defaulted to aux-fed subs.
Hey, Tim. The biggest reason for me personally is that running a matrix (or letting the system processor do everything and simply feeding it my LR mix, which is my preferred method) makes a clear divide between my console is for mixing, the processing or matrices are for wrangling the PA. When I'm choosing what's going to the subs or not, even if the send levels are at unity, I'm having to think both like a mix engineer and a systems engineer at the same time. Feeding it my LR mix saves me subgroups/buses, keeps all my processing in one place, and I can trust my board mix will sound great since I'm not having to think about the LF in my mix vs the house system, assuming my mix is great ; )
Even the matrix outs aren't much use to you. If you're 60m away at FOH on a festival gig what the point of having control of the infill level when there's no chance you'll ever hear them, you really just have to trust that the System tech has it all properly set up. Also turning the sub level up or down on the matrix can be though of the same as having access to to the system processor and turning the subs up or down on there. Doing this after its been time aligned is then screwing the timing up as is inadvertently shifting the crossover point higher or lower as you adjust the level of the subs relative to the mains. For me LR all the way straight into the system processor.
I'm operating on a much smaller scale than you. But I have found that my sound is much better if I run subs from an aux. HPFs do work to some extent but have a slope. And mics and acoustic guitars do generate low freq signals which are just junk. My tops can do all the LF needed by any vocal mic or acoustic guitar. So I am very particular about what I let into my subs: usually kick drum and bass ONLY .... sometimes also keys if there is no bass. My bottom end sounds much cleaner when I do it this way, so regardless of any theoretical discussion, I will keep doing it this way, and I'll keep recommending it for people to try. In the end, whatever works for you. Aux subs work very well for me.
For me it really depends on the system and how your console brand implements auxes and matrixes. I find, specifically on digico consoles, running subs as a matrix that you can choose weather or not a given channel sends is nice. Some systems implement this differently, and I find using whatever gives me the most control over the sound is generally the best to use. If I’m on a large PA with delay subs and massive delay line arrays as fills, aux subs may not give me the even sound across the audience that’s desired. It’s just a tool that’s sometimes helpful and sometimes not :) love the content btw
I would agree. If I am in an arena with multiple hangs, Each zone of PA is treated as it's own. For your example of large PA with delays and out fills, I may have the Main L/R zones with sub on aux, where my delays and out hangs are run full range. Again, like you said, different rooms and different gear builds, have to be treated with flexibility. Last month, I have had to build a show with a mono-block of subs in front of the stage, a regular point source set-up, an inline cardioid subs, and once a di-pole cardioid set-up. 3 weeks, same band, 4 different sub set-ups. Again, good job to Michael Curtis for initiating this dialog. And good job to you for bringing more information to the discussion.
Reason #4 is a very good point that I sometimes forget, well said. I sometimes have to use an analog console, with fixed slope and frequency for HPF. In this case I would argue in favor of using an aux. Nevertheless, thank you for your well argued insights!
You probably don’t remember but several years back at KPC you and I actually had a conversation about this exact thing. I hate mixing separate to the subs for all of the reasons you give!
Really valuable information to consider about system and mixing workflow. I think it may be great advice for beginner engineers/techs. I just have a few questions that I need clarification on. 1. Can’t you utilize bus processing separately and mix levels on DCAs for instruments? I do this a lot. 2. Using a hpf on channels and lpf on the system how much different is this than using a crossover? If you are streaming with subs on aux, it always makes sense to reach for eq as well for tonal changes unless you’re compensating for serious abnormalities live. 3. Transfer function point is valid, but if you keep the system close to full range and use the subs as low end enhancement. Would this allow your full range PA mix to be sent to the transfer function? It seems viable to feel out the low end needs based on the event/crowd engagement, etc. Thoughts?
Hey, Leif. Great points here. 1. I'm not quite sure the routing you're trying to get across here. Buses on most desks can't be routed to another bus, so the aux doesn't get the processing? 2. A hpf on a channel is very different in that it is much farther upstream. All monitor sends, PGM feed sends, main LR sends, etc. would be affected by that. And I'm not saying it's impossible to have the aux make a sensible balance of low end vs the stream, but I do think it introduces another unnecessary variable. 3. If I'm on a system where the tops barely get below 80Hz, then the subs are more than just low end enhancement. It's a good idea in theory to use the subs more like an LFE channel, but on the shows I'm on they're treated like an extension of the whole PA, not for effect.
1. Ah, right. I got turned around in my thoughts about parallel processing vs inline bus processing. It wouldn’t make sense to send the bus with HF content to the matrix either. The engineers I’ve worked with process the kick and toms individually and only send bus processing to the tops (paying attention to phase coherence). Then mix level on the DCAs, but this does require extra brainwork in routing and mix decisions. 2. You’re absolutely right in saying the methods of system design/routing will be more work to account for in your design/mixing. 3. I understand clearly now, not sure if I missed this in your video. It is important that your subs feel cohesive to the entire system with similar processing. I think your information can be quite valuable in setup especially with a similar system and managing the entire show smoothly.
Thanks for this video! I think I stop using subs on aux for awhile and see how it goes. I was always afraid of bad stuff getting into the sub, but I'll try your EQ strategy for vocals with the low cut, and two high shelves. Do you have some other recommendations for how to EQ guitars, bass and drums? I need to learn more about using EQ for better sound. Just looking around your channel now.
Thanks a lot! I have a free PDF in my Audio Toolkit called the 9 EQ Pivot Points that I think would be helpful for you when it comes to EQ. Although there are specific techniques and frames of mind for each instrument when using EQ, having these "macro" ways of thinking about each part of the frequency spectrum applies to all sources.
@@MichaelCurtisAudio I've been playing around with not using the aux-fed subs some. One thing I noticed is there is definitely *some* vocal content that is going through the sub even if I use a 160hz hpf. i guess it's not possible to completely eliminate the vocals, etc. from the sub with this method, just reduce them? that may not be a big deal of course. If I'm applying the hpf and maybe some low shelves to eliminate more of certain channels from the sub, will live performers be upset that their monitors make their guitars or vocals sound too thin? I'm wondering if it really makes much of a difference for my small setup whether I use aux-fed subs or not. I usually just have 1 sub and 2 tops at gigs (crossover is 100 Hz b/w sub and tops.) Is the phase issue really that big of a deal if I have the sub adjusted independently of the mains in that case? I never do a live stream, so I could see that being an issue with the aux-fed method, as you indicate. Is there a difference between increasing or decreasing the volume of the sub through the aux and doing it through turning the volume control on the sub up or down?
i do a full range setup and depending on the venue too if there are lots of low energy then i adjust my hpf either from 120 to 200 just depends on the venue, but im just doing small events not big events
My updated take on the topic: th-cam.com/video/wqXVUmTv4iY/w-d-xo.html
Hey Michael,
I saw your update. But I didn't understand how we can apply the philosophy of Dave Rat (sub on separate send) without using an aux.
Maybe using a group feeding a matrix dedicate to the sub. That seems very similar.
Thanks for sharing your knowledge.
Thanks for this article. I have been constantly wondering about this since working in live sound and tend to be of the same opinion. I've done it each way, but it really does seem to me (coming from the studio, and thinking from a translation perspective - be it for streaming/broadcast or for a feed to another room) that it's better dealing with the PA as if it were a single full-range playback system.
I can understand the business with the transfer function, but even working in a 1000 person capacity room where visiting engineers often use SMAART, I really haven't seen them monitoring it during the show. They're just using their ears then and working the mix, or EQ'ing the master GEQ a bit to compensate for what they're hearing.
It's like a lot of things in audio: it's one way of doing it. I've found over the years that it's better to stay away from holding an opinion that states someone should never do something. Some of the reasons I love using aux fed subs is that I don't have to HPF nearly everything. I don't want acoustic going to the subs and I don't want a HPF on it. I also love having the ability to give the subs more level at lower volume to compensate or giving them a bit of a boost to emphasize some moments. Yes, the acoustic crossover changes, but while system design is linear and analytical, running sound is not. There is room for some of the artistic opinions and if no one gets hurt, then go for it.
Thanks for weighing in here, Steve. You're totally right. It's one way of doing it and you're more than welcome to run your shows how you see fit. And you probably get great results for how you put together a mix.
@@MichaelCurtisAudio Great content by the way, even if I still like aux fed subs lol. Keep up the good work!
@@steve01010 Thank you very much! I appreciate you being able to hold the tension of "sure, we don't agree on everything", but still appreciate what else I have to say. Glad it's been helpful to you.
Can you not just get a sub with a hpf?
@@__Nata_he’s saying he doesn’t want a HPF on the acoustic instrument (and many other inputs), which usually cuts off most content going to the subs (though the HPF on most digital consoles is adjustable).
08:30
Sure you can send group to an aux on x32:
1. take 2 free channels, link them to be stereo
2. choose the input of those channels - the buses of the group
3. send the channels to an aux as usual
You're totally right! Great point.
I have been a concert engineer for over 20 years now, so I live by the motto of not telling another engineer how he should do things, just like I wouldn't tell a musician how to play HIS instrument. That said, I feel that some of the things you mentioned were made for the wrong reasons. I am neither an electrical engineer nor a comp programmer, so I don't know the exact physics of what is going on under the hood. But, there is a stereo summation from Main LR, that gets decorrelated when moving to Matrics. When I was first shown the difference, I had to go back to my shop and experiment for myself. With a 2 tops over 2 subs a side, stacks, I wired 1 top to 1 sub on each side with one amp system, while hooking up the second speaker set to a like amp system. Being able to A/B the two set-ups with one being fed main bus and the other from matrics. There is a noticeable fidelity change from one output to the other.
As for the lack of full range on your main L/R bus, when using subs on an aux, your left/right outputs are still seeing full range, and anything that you matrix off of your L/R is still full range. Your sub is only affected after your system crosses over at its designed frequency, With that being said, your sub send will also send a full range signal to the sub channel of your amp, where at that point, your system will cross over, filtering all other frequencies from that full bandwidth signal.
With proper "system" gain structure, there should be no audible change from a full range system to a 'subs on aux' system with channel aux send at unity. You shouldn't have to treat your channel equing any differently than mixing in full range.
It isn't about having more steps to do. It is about having less to do! In most "Band" set-ups and sound, it is easier, and quicker to dial that sub aux when you only have a few instruments that you want to go to your subs vs. having to run a high-pass on 20 other channels to get them out of the sub bandwidth. This also has added benefit to your amps, being that they have to work less when you don't have all the summated noise floor that every channel ads to your outputs. The sub drivers will also become tighter if freed up from having to try to reproduce sounds from the entire mix, just like the example of the pre-fader aux send that is missed on your source music channel, you will still be able to recognize a song due to the whole stereo mix of the source channel. "if you send it there, it will try to produce it", best option is to only send what you want to exploit that frequency band, i.e. kick drum, floor tom/low tom, Bass guit, keys, and other instruments that live in that bandwidth, your overheads, for example, should be as far away from your sub bandwidth as possible, even if high-passed.
I also do that to front-fills when we are playing a smaller venue. It is only the channels that get lost over the stage volume, i.e. vocals, acoustic instruments, etc, that I feed into front fills.
This only a cursory explanation of why I use subs on aux and not matrix or mono. I am happy to get more in-depth on this, if interested, but this comment is already turning into a book.
For me I run aux fed subs. I set the subs up so they are roughly the same volume as my tops and so I can have as much of an even frequency response across my PA. Once i've done that I only send things to the sub at unity and then forget about it (and also link the PA master LR with aux/mono. I use the aux feed as more of an on / off switch rather than a 'how loud I want the bass' switch. I like this as it acts as an immediate high pass and saves more energy for things that are routed to the subs. I do agree you can get caught up in thinking about routing more than actually mixing the channel but for me its a 'set and forget'.
Glad that approach is working for you!
Makes sense to me. I think most people arrive at the same conclusion considering these questions. Any reason I can find to make things easier.
Thanks to both of you gentleman for guidance🙏
Sick theory. That comparison to surround sound was brilliant. Thanks for sharing!
Thanks!
I think it all comes down to approach, coming from a sound engineer background a LR mix makes more sense. It's how I've always mixed at venues and it's worked fine to date. If people prefer aux fed subs, all the power to them. I don't believe there's one better way over another, if you can make it work, you made it work. The crowd don't know, they're not sitting there like "can you hear this A1 isnt using aux fed subs!!".
Great thoughts. Related to #4 I would also add that when designing systems for permanent installs like churches, schools, community theater and similar venues where you will have a wide range of mix engineers, including volunteers, using the matrix approach and a single fader will be much more user friendly and keep them from getting lost. You set the system up properly and turn over the system with confidence.
Great point! Yes, I do feel like it's much more intuitive than having to worry about all of your send levels.
I try to maintain an open mind. I do typically run my subs aux style. However, I do like the concept of this approach and the benefits that could come out of it with regard to tonality, TF translation and stream balance. I might have to try it out at my venue! Can't knock it till ya try it! If it doesn't seem to work, it's easy enough to switch back. Keeps ya fresh!
Give it a shot and let me know how it goes!
This is what I'm thingking too. If a reference music can go to a PA without mudding the vocals that means we can do it in live also, its only the matter on how to use your eq on your channel.
You got it!
Reference music doesn’t deal with feedback/live mics or the same kind of dynamic range or gain structure as live music. Not at all the same thing.
Question here.
I've been learning about aux subs and watched this to combat what I've been learning. Mixing at a smaller church. 50x80 room with overflow rooms open to main room (zone 2)
I have a external PA processor with only 2 inputs. How do I control different zones levels and subs on the console but still use the EV DC-one processor.
You use 1&2. Left/Right. 3. front fills (in my case overflow zone 2) 4. subs. with matrices, but i only have 2 inputs on my processor. Would I bypass the processor to do this and just go straight to amps? Or the processing on the matrices would output the stereo bus to the processor post fader with the sub fader affecting the stereo output? I have new gear on the way and i want to understand this stuff before i route the new console.
this makes perfect sense to me. never stop challenging norms . it's how we grow. there will always be people who say outside ideas are invalid. even f they eventually are, trying new ideas is how we grow. i love this channel. one of the most eloquent educators out there. i wish i had your savvy at your age but i'm a late bloomer. by the time you are my age you will be top notch, no doubt.
Thank you for the encouragement!
I use the main L/R output for my subs. I can take R for the tops and L for the subs after coming out of crossover with the high and low. I use the PAN knob on the channel strip to assign each things at channel level to the subs. For example, for kickdrum I PAN hard left and also compliment with the EQ low knob on the channel strip. For vocals , I PAN right and also use the EQ on the Channel strip to achieve a balance for the low ends and high properties of vocals . It works perfectly for me in house of worship and all applications
Thanks for sharing your workflow!
This is what i do too
Hahah ıts crazy
I think there's a general misunderstanding as to the intention of aux fed subs. It was never intended to use as a volume control for the sub freqs of an input. All the sends & the aux master should be set to nominal. It was intended to simply keep the subs as clean as possible by not assigning channels that you don't want in the subs which also reduces ambient low end on stage from leaking back through those mics into the subs. With digital consoles these days you have a lot more at your disposal to control the low end on an input as needed. That was not always the case. It's arguable as to which method get's you there quicker. One thing for sure, there's a lot of misunderstanding & therefore bad use. Anytime you adjust these faders off nominal you're changing the crossover point...
Great point here, Tim. Yes, before I switched to either feeding just my LR mix or running subs on a matrix I ran my aux fed subs that same way. Everything sent at unity. If you do end up running into feedback issues with certain sources in your subs, that is certainly helpful.
@Michael Curtis So on the WING would you still use matrices or would you use the 4 mains?
@@Cbamptronious Definitely the eight matrices.
I really don't think your tone was bad at all... thank you for the info. I really agree and enjoy your content, even when I disagree. Keep it up!
Thank you for the support!
Thanks for your thoughts. I see one issue with sending a copy of your entire mix to the subs and that is that in the case of vocals you are right in that a recording doesn't have the big bottom on the vocals that many people seem to leave in them in live situations but I think we need to explore why that is a little more. Yes, some folks have not quite understood why we commonly don't use much bottom end in vocals on recordings. That is true but the thing that some people don't understand is that the best way to achieve any specific sound especially in a recording is at the source. In the best recordings the vocalists are a good distance from the mic thereby creating far less proximity effect than with mics on a stage. Heck more often than not even lectern mics are closer to the face of an orator than a common studio vocal set up. Also something to note is that lectern mics are commonly hyper or super cardioid designs because they need the off axis rejection but with that the trade off is that they suffer from excessive proximity effect. Some consoles offer a -24db/oct cut but with that if you look at the curve you will note that above the cut frequency they also ten to boost information which is most commonly not a desirable effect either. While using the crossover as a low cut is not going to fix your recording it can at least make the house mix more usable when using substandard quality mics (we commonly record with mics costing in excess of $5K. Stage vocal mics are commonly some of the cheapest mics in the box. While the cost of a given technology is not a direct correlation to sonic quality it does in fact factor in.) An alternate to correct for the record feed which I mostly do from stereo matrixes also is to run the vocal through a buss that is doing some of the global corrections for the vocals/ for example commonly engineers spec the same mic for all of the vocalists who are performing together. There are some good reasons for that for those who don't understand but that is another topic altogether. Suffice it to say that undoing the "58 curve" is something you can do as a global setting on a subgroup while using your channel eq to fix specific issues for the various singers as well as some consoles allow you to low cut in both sections or at least "low shelf" the bottom. Also inserted eq can be your friend there as well.
Great thoughts here! Thank you for sharing. That all makes a lot of sense and I totally agree that the proximity effect becomes much more of a bear in live sound.
Yes, I a great "compromise" approach is to have a Band subgroup that passes through to the LR unaffected then a Vocals subgroup that has any needed low end shaping so you don't have too much rumble. I can see how that's especially effective if you're mixing monitors from FOH and the lead vocalist doesn't want to hear their voice too kneecapped on the low end if you don't want any excess rumble in the PA.
Use the mix minus method, to control only sending lows to the subs using aux pre and post auxiliaries
@@MichaelCurtisAudioBringing up the subject of fold-back is a whooooooooole different topic, LOL.
Aux fed subs are appropriate for hiphop and DJ-centric venues. In those situations you often ride the gain on the subs to suit each particular track or performer, as well as punch up the energy in the room. For live bands, however, it's better to use FOH speaker management via well-tuned external crossovers. That way your master fader controls everything as it should, and there's no need to complicate things with a layer of matrix outputs.
Thanks for sharing.
Some of the old crossover/processors in clubs were right in front of the DJ for easy access. Now it seams the "hands off" approach is more common.
@Bogdan Chepurny - For a parallel livestream mix, I run a separate stereo submix that is routed post-fader, and set all faders in the active channels in the livestream at 0db. That way, I can choose which FOH channels are also routed to the livestream, and the livestream channels track the FOH channel faders. I don't use compression on FOH, but have found that livestreams need extra compression to maintain a more consistent volume level.
Try a multi-band comp (Like C6) or a Dynamic EQ (F6). I do this for every show with pre-recorded source tracks as the main source of music. Most of the time, the source material is mixed over emphasizing the lows and highs. If no multi-comp or dynamic eq is available to you, you can use an analog compressor with a sweepable key frequency. If you insert it onto you sub bus, it should give you the control that you are trying to achieve.
I’ve run subs in an aux for so long. I’m used to some of the “oddities” like walk in music and things that are hitting those subs differently. BUT. I have been watching your stuff and I am trying the LR to Matrix mixing for some clients to see how it works. I’ve got a room to test soon and I’m rebuilding their X32 for matrix feed and I will try the subs this way and A/B it to see how it works.
I also see the benefit from a mixing standpoint. You just mix faders at the end of the day. All those tweaks should represent a whole system that sounds good. Plus it cleans up your LR mix for reference and review.
When I think about training new people to mix, I can totally see this being a great choice. It’s more wholistic!
Thanks for considering this new approach! Let me know how it goes.
Michael, I have done this both ways. On very large shows I have done the Left/Right to 4 matrixes, Left/Right/Sub/Fill. We always do it in that order. We do get the request to set it up Left/Right/Sub/Fill for many of the artist we support where we are doing a Aux for sub and Matrix for fill. I myself prefer the way that you suggest and as you said if we need to do a live feed for recording, we can just simply pick another Matrix and send it to the live record feed. We did this at a corp show last week. As I said, I prefer to do my feeds as you suggest, however I have clients who prefer the aux method and when they are paying the bills we do as they wish. Nice video.
Thanks for sharing, Bill! Yes, totally agree that your system setup must be flexible enough to accommodate other engineers who run their mixes with an aux send as well as fills.
I'm the engineer at a relatively well known venue and the only touring engineers who show up and fiddle with some alternative to aux fed subs are younger than 40 and haven't been doing it for very long. On the flip side, every single 40+ engineer uses aux fed subs. The only real difference at the end of the day is that the younger engineers are all stressed out and having a bad time because they've inevitably overcomplicated things in an attempt to... not do it the way that's worked for decades? All the routing tomfoolery in the world won't make up for a fundamentally bad mix, and typically these engineers end up wasting valuable time when I hand them Left + Right + Sub drive lines that just go straight to the amp rack and it doesn't jive with their Proprietary Mix Magic.
Of course, to each their own and there are myriad ways to run sound, but the older guys aren't doing it because they're luddites, they're doing it because it's simple and effective.
I'm 1000% with you that this pervasively overcomplicated mix trend, especially with young engineers, is debilitating and unhelpful. I've seen too many talented young folks get so bogged down in miles long Waves channel strips on the hi hat that they forget to ride the lead guitar for the solo. Rant over : )
A good mix is a good mix, full stop. I'm not trying to stir the pot and say that these veteran engineers can't get great results out of an aux fed rig, I'm just saying with my workflow I prefer using matrices and here's why. That's all. If I'm system engineering for a FOH mixer who wants to send LR+Sub, they're more than welcome to.
TLDR uses a matrix
@@jakestanbro959 I just ran sound for a band at a large festival and several of the other touring engineers kept complaining about how the sound system wasn't tuned properly and there was too much low end. Turns out, they were all using subs on a matrix. They were complaining about an L'Acoustics line array sounding bad while making an active choice to remove their ability to simply turn down the subs with one fader.
There are a lot of considerations when it comes to routing signal through your console. It not only depends on the capabilities of the console (some can't route groups to auxes and some can't route inputs direct to a matrix, or some don't have matrices), it also depends on what the PA is, how it is setup physically, and what system processing is in place. My first preference is to use group-fed subs so I don't have to worry about getting pre-post incorrect. The channel processing is still full range so my LR buss is still getting all the same low-end information which is getting recorded. It's up to my external system processor to handle the crossover between subs and mains. In some cases, if you have flown mains and ground subs, you may not wish to high-pass the mains anyway. In that case, the subs are definitely just icing on the cake and need to be treated more alike an LFE. If I really need the subs to carry the whole PA, then maybe the approach changes.
I strongly agree that variable sends to subs is a straight up terrible idea. I'd still use an aux in a pinch but it would only ever be unity sends and let the system tech do his thing (I'm also primarily a system tech, so there's that). On an M7CL, you can't have groups, only "fixed auxes" which is the same thing anyway.
I sort of don't care about the transfer function reasoning - I think you should mix with your ears, not your eyes. I've never mixed live with a constant TF and don't feel the need to. I still argue that with group-fed subs, the TF won't be completely wonky, it'll just appear to have a low-shelf boost because, again, your LR buss still has a copy of the same information as the subwoofer group.
Lastly, I strongly believe that high-pass alone is insufficient for low-end management. The HPF frequency is the 3dB down-point and the roll off is still a curve. A 4th order LR filter at 100 Hz is only 6dB down at around 80Hz. For every non-high-passed mic on stage, you're gaining 3dB. If every mic on stage is only high-passed at 100Hz, you've now added enough low-end energy back into the system to fight your crossover or high-pass frequency set points. It's still totally possible to get an 80Hz or 100Hz ring in this setup.
You got the point about a studio track through a PA incorrect. Once a 2-track is printed, the high-pass filters used on each channel become printed and there are no open mics. Microphones feed back, not speakers. Everything in the track will go to your subs, yes, but that's only if the information is in the track and that's why we use a system processor to low-pass the subs.
All great points here. Like you've mentioned, the routing and processing available to you on each gig will dictate how flexible the system can be.
I've personally found the high pass filter alone on my live music gigs to be sufficient, but on this most recent corporate gig of mine when I ran my LR Bus as the source for all speaker destinations I had to do more LF ring out on my lav group than I usually do since the PA tilt had a significant LF tilt in the PA because there was also a live band. So there the HPF alone didn't work, which proves your point.
All things considered, a variable aux alone I don't think is a good idea, but I'm starting to change my tune a bit about strictly sending the LR mix into the processor and having the processor ONLY manage the LF. I'm actually in the middle of rebuilding some of my corporate console file templates and will likely be sticking with LRSF and taking my lavs, handhelds, and podium groups out of the subs. I appreciate your feedback.
watch Dave Rats video on Aux and sub sends, you'll see why its a better method of mixing live audio and keeping unwanted frequencies that filters will not completely remove. I've done both depending on who's system Im using and will always use an aux send for subs if I have the choice. I politely disagre with what you are saying.
I've watched his video and I respectfully disagree with his approach as well. Thanks for weighing in!
6:17 If you Hi-Pass the Mains and Low Pass the Auxiliary Send that feeds the Sub at an appropriate frequency, 80Hz for example, and then send your reference track to the Sub on that Aux, no vocals should be reaching the subwoofer.
That's correct, but that's assuming that the subwoofer downstream of the aux send has no other processing after your console. If it's an active subwoofer, putting a high and low pass on the aux will double up on the crossover processing and narrow the sub's bandwidth unnecessarily.
@@MichaelCurtisAudio Hi pass the Mains, low pass the Aux that feeds the Sub.
If the Sub is already being low passed at the sub itself? Then, don't low pass it at the Sub Aux, or vice versa... Or choose which low pass you think sounds better.
Easy work around if that concerns you..
Then we're right back at square one - running no LPF on the aux send means we're still sending a full range music track to the sub, then letting the sub itself do the processing.
@@MichaelCurtisAudio No, Bro... I said it twice. "...Hi-Pass the Mains and *Low-Pass the Auxiliary Send that feeds the Sub* ..."
@@nodaysback1 That would still double up the low pass filter on the subs. I promise I'm not trying to be confrontational, just having a hard time following the logic.
When I first heard of the subs on aux idea, I had the same thoughts as you are expressing here. Thanks for confirming what I've been thinking about this for some time. Good video.
I still just use a crossover lol. I will explore this method for sure. I've tried aux fed subs and just went back to an external crossover because I was constantly "balancing" the system. This would eliminate that👍 Oh, and I always MUTE the walk-in music channels right after I fade them out now. I had the same thing happen lol Great video! Cheers
Thanks a ton, Steve!
If you have a multi-speaker system, you will still need to use a crossover, whether it is passive or active. Now-a-days, it is mostly programmable amps that take care of crossover functions. If you are still running analog "dumb" amplifiers, you will need an active crossover to run your speakers correctly.
You said "I've tried aux fed subs and just went back to an external crossover because I was constantly "balancing" the system." This is kinda confusing. Without the external crossover, subs on aux doesn't work in the first place. Unless you are saying that you do something like low-passing the buhjesus out of your sub bus, and then send that signal straight to your amps. That is the only other way that I can see this happening, and that is just silly talk, lol.
Shout back if I confused you, that ability seems to come naturally to me, lol.
For me, it boils down to several things:
1. What console am I working with?
2. How many outputs do I need and how many are left?
3. What type of event am I mixing for?
4. So I have any external processing control for the PA?
All of that is going to influence whether I use aux-fed subs or not.
Thanks for the video but how to propertly fed subs when I don't have any matrix possiblity right on the mixing console? Is there any other way than aux fed subs or using external crosover processor?
people seem to miss the point of aux fed subs ..the point is you send only sound sources that has sub frequencies you want to the aux .so like plufs on vocals is not a problem .don't need subs for snares , rides ,crashes ,hi toms splash Banjos and ,Vocals ..there mics will only pick up wind and handling noises hi pass filter do not stop every thing
I might be wrong, but I don't think @MichaelCurtisAudio misunderstood the idea, he just said that modern consoles offer variable HPF and low shelf/peak cuts on every channel, and therefore this point is moot. IMO, if you are used to mixing in the studio on full-range speakers, the idea of mixing full-range on a PA just makes sense.
1A/3/4. I would best describe as make your life easy by not doubling the mental load of keeping track of where your decisions are. Similar to using a compressor - volume = volume out with the make up gain.
1B. I don't really buy the broadcast limitations. If you are using the FOH mix to feed broadcast you are already making a sub par compromise & most of the playback devices won't really produce the low end anyway. If you want to include the sub in broadcast then you can use a matrix to combine it with the LR. Ideally it should be a complete separate mix & if you have the budge a passive split (or like the Pro 2 with completely separate pres in the remote i/o).
1C. Yep shelf that low end away on everything that hasn't got bottom end you need.
I hate aux fed subs. I learned on 4 way live mono. With a crossover. Club system I work on mostly we have two systems prosessers Yed into the amps. One for the DJ on for bands. I get sent out on many systems with aux fed subs and it is one more thing to think about. I prefer a system proscessor or X over. I am not that savvy on smmart. I would like to hear about your setup on the mono bus for smmart. These days you can’t burn an aux for subs when everyone wants stereo in ears or 10 separated mixes. I found what you said very interesting
I’ve seen some recordings missing kick drums because the mix engineer simply decided to run the kick only to the sub aux. Most churches and bands have volunteers, and probably someone from the band is doing the mix. Having less aux to worry about is great. A good and leveled PA is much better than mixing a separate aux.
Two things: first is something I discovered recently, second is something you confirmed.
1. Adding low end shelf to the sub channel isn’t necessarily a good idea, due to affecting the crossover on the parametric eq (so far this is an observation)
2. Continuing 1, eq from input channels instead of thinking it’s a global issue. That changed the way tracks sound, as well as overall mix.
I use the Center channel on M32, factoring in what I do or don’t need in the mains. This works 99.9% of the time, especially since there’s a dedicated rotary knob in on the penthouse section. Even the TF series suggests a center channel via Sub out, yet I do like having the option of stereo subs depending. I’ve since then summed both sides to mono at my Sunday setup, but hasn’t caused any issues so far.
What about Headroom . . . Sub Frequencies eat up a lot of Headroom on your Stereo Bus/MixL/R ?
Also thought you would mention how Aux fed Subs change the X Over Frequency due to variable levels.
Lastly there is the question of Low End Contour on your whole system. Aux fed sub seems to give you control of that easier than with L/R and EQ.
When a gr8 Mix Engineer is Mixing A Good Band , L/R Stereo all good . . . . When the source is varied between different styles of music , especially playback / edm , how do you get around to control your Sub , considering different genres require different LFE contours ie. +3 , +6 , +9 dB.
Thank You for sharing your knowledge and videos. They are amazing. Learning a lot.
Hey, Mandla. Great questions.
A subwoofer will filter out unnecessary frequency content before trying to reproduce the waveform. So, the difference between a mix that only has kick and bass guitar in vs a full mix once bandlimited to the sub range is incredibly similar.
I'm not too concerned with the crossover changing unless the mains and subs are coupled together.
A mix engineer should just worry about the quality of their mix leaving the desk. The systems engineer can then give them the desired response of the system easily with a low shelf on the rig, no problem. Most large format mains speakers, like L-Acoustics K1 for example, go down to 31Hz themselves. So, if subs are on an aux and the engineer asks for less sub, you're taking out the subwoofer, but there's still PLENTY of low end coming from the mains. So, feeding the entire rig LR means you can apply a low shelf across the whole thing and shape the tonality in one simple place.
Good points, well made. But how do you respond to those who would say that a typical mixer channel strip HPF doesn't have sufficient rejection to keep microphone handling noise and other unmusical LF content out of your subs? (I've heard it argued that you would need an ultra-steep HPF slope to properly eliminate the unwanted microphone LF, but even if you had such a sharp HPF available, you would risk excessive group delay distortion near the passband edge.)
Aux fed subs makes a lot of sense to me. Other than kick drum bass guitar keyboards maybe floor Tom you don't need anything else in your subwoofers. I cross over my subwoofers at 90 Hz. And actually I do not feed them off and auxiliary. I use the Center channel out of my M32. so if I want to ride up the master well that Center channel is right there next to it so I can ride them up and down together which I never do anyway. I started my Sound reinforcement company in 1980 and I forget when I started feeding the subwoofers off the auxiliary, but it was a game changer for me. As far as streaming feeds or other feeds, it's really not a big deal as you make it sound.
To your first example… Reason I use subs in separate bus is because vocals in studio or instruments are in a perfect environment. Vibration and wind free. A HPF won’t fix that in a chaotic live set.
At my regular gig, I use an m32 and the gain on my PA never changes, so I run everything to main L/R then use 3 matrix, one for L, one for R and a mono sub through out 14, 15 and 16, and 9 times out of 10, my sub matrix will be at -20 and rarely ever moves
Re X32 Buss to Aux (8:32): Yes you can route a Buss to an Aux, or any other channel, (and therefore also route a Bus to another Bus, via a Channel)
I agree with the Subs (indeed all the PA) on Matrix after the LR, for simplicity of control and trouble shooting. After all, having spent the time (and money if you have bought Smart) to get a good even frequency response in the venue, would you mess with the PA balance (subs level) during the show rather than ‘tuning’ the band sound with Ch or Group Eq.
Thanks for all your brilliant tutorials, especially on cardiod Subs, going to be experimenting with this next time I can get into the venue on a non show day.
Ah yes, totally forgot I can put a bus on a channel and do routing that way. Thanks for the reminder there.
I'm glad you've found my videos helpful! Let me know how the cardioid setup goes for you.
Holy cow thank you for addressing the elephant in the room. I keep seeing these posts from big name mix engineers (Dave Rat and others) talking about using aux fed subs. Im not gonna say these guys arent mixing killer shows. But i dont think that way. I come more from a studio mixing background, and you NAILED almost all the concerns ive had with aux fed subs for live show mixing. I will add one here- processing done on your master LR buss is weird and skewed when the low end is on a separate bus. I like to mix with a multiband compressor and limiter on my master buss. If my low end isnt hitting that, what am I supposed to do create another compressor just for the sub aux???? Its just way too much to have to think about. I want my PA sounding like I want it to sound, then mix INTO it. If you have to be adjusting overall low end levels on the fly, you havent got your PA tuned well. If my kick drum isnt hitting at 50 hz the way I expect, I know the mic has either been bumped and is off kilter, or something else is going on.
Heres another example- last church I mixed at for a while had aux fed subs and it was a constant hassle. I could NEVER get the top end bite i needed from the kick drum. Same mic ive used for years. Kit was tuned well. It had to do with the way they tuned the PA, the crossovers and DSP happening inside the amps. I was boosting 8db at 3.5khz and still didnt have the top end I needed. After a little while i realized the kick wasnt patched to the top AT ALL. Sigh..... got that patched, things got a bit better but it was still a constant battle to get a simple kick sounding the way I wanted.
If your PA is tuned well, you should be able to get dynamite results without aux fed subs. Use high pass filters as needed to prevent unneeded low end from hitting your subs. After all this time I just still dont understand the need for aux fed subs.
Thanks for your feedback here and I'm glad the points resonate! One thing you mentioned that I wished I had thrown in as well as how it prevents any master bus processing.
The only time I find myself using aux fed subs is on corporate gigs if the subs are very close to the stage and I have a lot of lav mics. If someone hits their chest I don't want the "BOOM" to be so accentuated. Other than that, matrix fed or just letting the processor handle it all is the way to go : )
Glad to hear you're keeping the vid up. You'll never please everyone all the time. Do you !!
Thanks, Tim!
Great video! I would suggest to handle the proximity effect of the vocals in a more "elegant" way, to use a dynamic EQ or multiband compressor on your vocal group. This way you only trim down those muddy frequencies when proximity effect comes in play. (I do understand this tool is not always available in every mixer)
Yes, great input here. Dynamic EQ is a more elegant solution, for sure, especially if the vocalist is inconsistent with their mic placement.
When I encounter a system that's set up with aux-fed subs, I leave it that way, but I set the levels "at unity", so the system is still flat, I'm just taking advantage of the "tighter" high pass filtration. (Boosting the sub level on a channel seldom gives me the result I want, so I don't bother if I am configuring the system.)
I run my my subs in aux for flexibility. I think it is very possible to set up aux fed subs in a way that negate pretty much all of the downsides you talk about. But it is good to be aware of the drawbacks of any mixing practices you use. I personally believe that if you are intentional, careful and understand the limitations aux fed is fine. I don't think your take is particularly convincing. The audio isn't ever really a coherent field for the average listener. Having discreet control as a mixer is important, there's no reason to limit us to just using EQ, compression, ect. Not having certain instruments go to your subs at all creates more headroom than just using high pass filter.
Hello, how can I make some bleachers in a Manuel way with my mapp3d app for places like fields, stadiums, etc.
Check this video out - th-cam.com/video/E9VLOZfyVW0/w-d-xo.html
Hi Michael,
First of all, thanks for your awesome videos. They share a wealth of information and straightforward approaches. Wished I found your channel way before!. I pretty much agree on your aux for subs philosophy. Especially when you have system processors that make all the division and parameters from within by just simply feeding a LR signal (like old 2-5 ways analog x-overs).
Just wanted to share that I use a Yamaha TF5 which has a Sub fader. It conveniently fits to the system processor which has L+R+ Sub inputs. Depending on the gig, I use the mixer Sub fader unprocessed or LPF it around 90Hz. In addition, when needed, I can bring it up or down to get an instant tonal balance at the FOH if any sudden environmental/unforeseen issues might happen. Streaming or recording are via Stereo Matrix fed from the L+R (all low end instruments like kick, bass, an others are always routed to LR main).
Thanks!
Abdel
Thanks for the input here, Abdel. Glad you've found my videos helpful! Yes, having your subs on a Matrix or its use Master bus is super helpful, especially it's a new rig or your environment might change. The TF5 is a neat little desk.
Can you do a video where you are showing us physically the different setups for sub on aux and then the way you recommend?
While the SQ series can send groups to aux, it doesn't make sense with regard to the arguments pro aux-fed subs. Because would not send the drum group to aux, but only the kick drum. However, especially on small venues, you might want to delay the drum group to align PA drum output with direct acoustic drum sound. Which would work with aux-fed subs, however at a much higher level of complexity. You'd have at least two places to visit in the console to change the delay.
Unfortunately, our mixer only has 3 matrixes, but I recently started using 1 for uppers, 1 for subs, and I'm experimenting with 1 for the live stream.
I'm assuming it's A&H SQ or Qu? I like those desks for the most part, but only three matrices is a beef for me : )
@@MichaelCurtisAudio yep! An SQ
I like to run aux fed subs because,
i use 2x dual 18 subs in the middle of the stage, then i have 2x single 15/18 subs on the side with my Array tops ontop for my LR mix.
Then i send the outside mic (for low-end only) of the kickdrum to the dual subs(aux fed) and the inside of kickdrum mic with a low cut of 100hz so i get mostly attack to the LR system. then bass guitar and the rest of the mix also to the LR speakers.
Is this an effective way to get separation of kick and bass guitar, low-end spread and a cleaner sound? what issues may occur?
Although I like your creativity, I think this overcomplicates things a little bit. Your technique borrows some elements from mixing on a front-field immersive rig. Although immersive mixing let's you physically separate out where audio sources are coming from, every major manufacturer I'm aware of with an immersive platform still recommends all low frequency heavy sources come from the same center sub cluster.
You've probably heard of Dave Rat double micing sources and panning them out left/right to get separation. I know you're not double micing EVERY source, but it is common to have an In and Out mic on the kick like you're doing.
What I think is worth investigating is how much actual correlation is occurring between those two mics. You can only mitigate comb filtering when two sources arriving at the same point are either decorrelated OR greater than 10dB in level from each other. Given that, I'd run some tests to see if the kick In and kick Out mic are actually all that "different". Hopefully that makes sense!
@@MichaelCurtisAudio Thank you Michael. your content is epic.
I still have some questions,
Is it not preferable to separate the kick and bass guitar's with frequency like this,
kick drum focus is 50hz to 100hz
Bass guitar low cut till 90hz with focus on 90hz to 400hz.
This way you don't need the bass guitar going to the centre subs because you have made space for it in the LR mix just above the kickdrum frequency, even better separation?
Thank you for your feedback
That's definitely a school of thought when it comes to "carving out space" in your mix. Although this makes intuitive sense, I as a bass player wouldn't want the bottom octave of my instrument to be missing : )
I think there are other ways to make sure both the kick and bass can live in the same space without clouding the other. That largely comes down to the arrangement and players first, though.
For me, it’s all about the situation I’m mixing for. When I’m doing talking heads, I prefer aux sent subs because I don’t want to roll off at 160. I want to roll off at ~100 because for intelligibility for talking heads, 100-160 has a very small sliver of frequency that helps make voice fuller. It’s nuanced, but it matters. If I’m rolling off at 160, I can’t get that nuanced frequency in my voice.
I use a K-Array system at one venue and if you don’t separate the subs from the top, the proximity effect on the podium is uncontrollable unless you start rolling off and using multi-band compression on the sub to take it. Instead, I simply don’t sent the voice to the subs but send everything else to the full system.
This eliminates many of the headaches but the pre-function music to subs…oof. Been there. Not fun.
But still, at the end of the day, does it sound good and is the client happy? That all that matters. For me doing corporate talking heads with a system where I can delineate what goes to subs vs tops, my talking heads need to stay separate in order to tame the low end beast.
Another argument against aux fed subs is that they dont track the rest of the system if you do any LR buss riding.
How about if the mixer have zone /sub output?
I could not agree less. But I appreciate your knowledge and personal experiences.
i think this is a matter of "simple but limited" or "advanced but cumbersome". i run our subs aux-fed and i like to run our bass guitar exclusively to the subs. ive found that it gives a MUCH better spatial separation between the instruments, and it gives me _more_ room to mix the other instruments. i'd heard from Dave Rat's philosophy that sound comes from different places, so thats what im doing. (i let tops handle sub frequencies with an EQ. theres not a lot if theres no bass guitar)
i will admit though, like you said in the video, eliminating variables helps me have a clearer head for mixing. i run a bit of kick drum to the subs, and it bothers me a lot having to juggle that with the bass, and with the whole PA. not to mention that whatever channel i run to the subs is always a different configuration to a purely FOH out channel which causes a hectic confusion sometimes.
i will try a linked-sub system again this sunday, no aux and see how it goes. i think theres a lot to say on this topic, very interesting. and very interesting video too!
I am running in the next 18 for local shows since it does not have any matrixes. How would you suggest that I control the lower end not using aux fed subs?
Mono to sub fan here. I like your theory as it forces you to make good EQ decisions, however it does not account for most consoles having only one HP filter slope on individual channels that might be less steep than what you’d want going to your subs.
Good point here. HPF flexibility is helpful.
Great video. I don’t disagree, but do have a counterpoint. With live PAs, we generally have an exaggerated sub to main ratio. Some level of a haystack in the bass frequencies.
With aux fed subs, the mix engineer is able to prevent vocal mics from going to the subs at all. Without aux fed subs, the only tool is the high pass filter.
Do you find yourself high passing at a higher frequency to be more effective in the sub region, when the subs are boosted 6-10db above the mains? If more aggressive on the HPF, that would affect other mixes for streams, etc.
Would love to hear your thoughts…
Hi Phillip that's a good point. I had a vocal with 85hz high pass filter. But I noticed it was still sending a bit of low frequency energy to the subs even though my xover freq was 80hz. I thought it had to do with a slope of the high pass filter. Anyway, that made me almost force me to use aux fed subs. Yes, I'd too like to hear your thoughts on this.
Great counterpoint here, Phillip! Glad you liked the video.
As much as it feels like vocals in the subs is the issue, in my own systems (without floor wedges) I have trouble with vocal feedback in the 200-600Hz range, which sits squarely in the custody of the mains. The highest crossover frequency I use for subs for most rigs is 100Hz, which would be a low G for a bass singer (and the open G string on a bass guitar). There's of course a slope downwards in level or frequency for the subs after that, but they're usually more than 10dB down by 200Hz.
I feel like the bigger issue is too big of a tilt in the LF on the MAINS. If I'm running a show that has both a big dialogue component AND a big a band component, I'll have the pink shift/LF shaping on the PA geared to sound great for the band, then use a low shelf to shape low end for my Lav/HH bus.
My system target curve shoots for a flat PA from 1kHz to 10kHz, then some tapered HF dropoff after that as you move from front row to back row. For LF shaping, there's a +9dB rise from 1kHz down to 100Hz, then it's flat from 100Hz down to 31Hz. So, it's PA systems that have a much bigger LF lift down towards the subs that I think pose a bigger issue.
Also, on BIG big PA systems the mains easily get to 60Hz. So, even if you did take your vocals out of the subs there, you've still got a significant amount of LF power coming from just your mains.
If you still want to make sure vocals never hit the subs, I'd run a Band and Vox subgroup, then route accordingly to matrices. That just makes it harder to do any overall PA tonal shaping without duplicating processing.
As far as vocal processing and EQ, these days I'm running HPF at 160Hz to start, then having a low shelf at 500Hz and a high shelf at 2kHz. These high and low shelves act as a "tilt EQ" together. If too much proximity effect, bring down the low shelf. If not enough top end to cut through, boost the high shelf. Then I have one parametric filter sitting at 400Hz to cut any mud.
Hope this helps!
@@MichaelCurtisAudioAlso, think of the harmonic's the subs unavoidable are creating ... there is actually more distortion in a "punchy" sub, so even if you have a 4th order crossover at 90 hz vill 120 hz and 180 hz come creeping in as byproducts.
There is another point to be made about the cumulative effekt of having a wast number of inputs lowcutted at the same frequency, the ripple or bump just at cut off - is pronounced
@@srendyhr5844 Yup! That can cause a ton of phase shift and weird frequency responses.
I engineer large corporate shows mainly. I usually run subs off a fixed bus, not an aux for corporate. The system is tuned full range, with the mains HPF to match the subs. The difference is that I only put things in the sub bus that I want there, and these are mainly video rolls/walkups/VOG/Playback. The channel counts on these shows are usually a whole bunch of RF lav/headset/handheld mics and fewer playback sources. I do still HPF these microphones but I only have to worry about that in regard to the main PA, because they do not go to the subs at all. With this format I can't add more/less sub per channel, either something is full range or in the mains only. If I am mixing music I will probably make the sub group into a variable [aux], but I will still tune the room with the aux at 0db so that is the absolute and 'correct' starting point for anything being fed into the subs. This just adds a little more freedom on something like a kick drum, to add that 'live thump' that is not going to translate well in a record mix anyway.
I do like to use my L/R to feed the Matrices, which is counter to a lot of corporate guys who go group to matrix and use the L/R bus for record feeds. I like to be able to do a few system wide eq moves on the master L/R. But this can occasionally get you in trouble for corporate depending on how much of a matrix hog you are, for instance maybe you put out a lobby speaker or ran a feed into an audio embedder and made it a matrix... then the client doesn't want walk-in music in that feed and you basically have to rebuild that feed. I now do an additional feed into the matrices that I call 'royalty', and I will put my walk-in/out music through that feed. If it isn't wanted in some matrix then I can just cut it from the matrix. Sometimes there are additional feeds to the matrices as well.
Some great tips here, thanks for sharing!
HPF and for that matter LPF are my fundamental tools for building a mix. They often are the basis of my equalization to the point I often need far less time getting a sound on a given channel once I’ve filtered. I can’t imagine why anyone would object to this. Most of my music mixing is for broadcast or release. I know the frequencies of musical tones and use that to narrow every channel as much as is possible. In symphonic spot mics, this is done without question. Ditto an electric band perhaps even more so.
If working in surround, my Sub is simply the speaker handling the lowest octave or two. I have never been happy with aux fed subs and leave them off if they are present. You are preaching to the choir here about ‘aux mixing’. A recipe for disaster and a tail-chasing exercise - I’ve never needed either.
Quesiton: Is the Left Right Matrix linked together as in X32 LInked Channel or is this even possible and why/ why not?
Hi Michael, I’d love to know if you still feel the same for corporate work. I usually do exactly this for music work, but for corporate I often do buses of different inputs (lecturn, lavs etc) straight to my various matrices to allow me to slightly shade down the lecturn in front fills for example to give me a tiny bit more headroom for the rest of the space. Thoughts?
i might agree with most of this if other people use the mixer, or if your live streaming off same mixer during live show. But disagree with most of this on my own mixer. As far as not having to think of where any signal is going during the show. I have that ll mapped in my head, so its easy decision in my head to decide if i send more kick or tom to the aux or boost the EQ. Its also way easier to tame the low end of a bass guitar by reducing the send to the sub vs EQing the lows out. Another huge plus is if you play outside in the wind. Its a lot easier to keep wind noise out of the subs, if your not sending most of your microphones to the subs.In fact, Iuse Matrices for each output, Left/Right Main, Center, Infill or Outfill, and 2 separate for subs. I have full control of what instruments or mics go into each matrix. Sometimes I will even send Kick Drum to a center sub, and Bass guitar and floor toms to the outer subs where I cant center cluster all the subs.
I get it but are you talking live sound or mixing a recording ? Just curious
Thanks for this excellent explaination of your preference. If im mixing multiple different sources. Ie headset mics, HH mics, close instrument mic, rifle mics etc. I set the console inp-grp-mtx. So bypassing the stereo bus. (Hear me out) So if I have big loud brass section who are loud onstage i can "dip" the send from the group to the front fill mtx. It makes the setup a little more complex but gives you a chance of evening out acousticly loud instruments. The default is grp send is unity so it makes it possible to do a full consistsnt sound check. So i only use this to attenuate levels never increase them. I think im going to try your way the next time though! great vid, keep up this great content
That's a cool workflow and makes a lot of sense! The feedback is much appreciated.
11:39 What I do is tune the room and then set the channel HPFs appropriately.
Isn’t the mono bus just another matrix in the M32 for instance, what’s the point of setting and wasting a generic matrix?
The matrix sits downstream of the LR Bus and inherits its signal and processing. The mono bus is a separate signal path. So, if you applied mix bus compression on your LR mix the same processing would not apply to your Mono bus.
The problem I found using matrix is: even after I lowcut the vocal at 120hz, there is still some reproduced by the subwoofer which cause muddiness
Then move the low cut higher?
@@MichaelCurtisAudio th-cam.com/video/hpFK1XOZuUg/w-d-xo.html
@@maizesoft Yes, I'm well aware of this video. Dave Rat has some good points, but I feel like it's a non-issue with most vocal mics. An SM58 already had a fairly steep LF dropoff below 160Hz and I'm usually high passing at least that high due to the proximity effect. I'm usually able to do a cardioid configuration on my subs which keeps more LF off the stage.
If I do need to get some specific sources out of the subs (lav mics, podium mic) I opt to matrix out my subgroups to the appropriate destinations vs using an aux for my subs.
I think it's only good for a big pro mixers or digital mixers, but for smaller mixer (like a Yamaha MGP16X or Beringer Xenyx XL2400) they doesn't have a matrix (a good one), so you must route subs from a Group, Aux, or mono(even Yamaha doesn't have a mono channel control)
I have tried this (matrix to sub) and aux or mix. Correct me if I’m wrong, sub send on a matrix; you are sending all content after L&R to the matrix. Are you creating a crossover?
I mainly work in the corporate AV world.
Hey, Robert. Great question!
Yes, all channels you want going to your full PA go to your LR mix, then that LR mix goes to your mains, subs, and fill systems matrices. I usually run matrix 1/2 as mains, 3 as front fills, and 4 as subs, then use more if i've got side hangs, delays, etc.
You would apply the EQ, crossover, and time alignment processing on the matrices, so that when they acoustically sum in the space you get the results you want.
Is this also suggested for DJ applications as well?
You are absolutely right! Modern films sound wrong. The sound is all boom and crunch. It doesn't sound natural. If you use a good processor it will sound real and right!
Very good video I'm using aux fed to fed my sub, but my livestreams sound weak but the room sound very good. Now where should I plug my subs, strait from the main speaker or else where.
Helpful and interesting ideas here. Thanks man!
Dave Rat just did a video on why he prefers the aux fed subs and I tend to agree with him although Pooch & Rabold have a video where they swear by a LR and no aux fed subs. I'm on the M32. Matrix 1 & 2 are Main LR like you said, high passed accordingly. I send only what I want hitting my subs to the M/C bus and then that goes to Matrix 3, low passed accordingly, LR 24 on all the Matrices. My fills live on Matrix 4. I like the idea of not sending any unintended non musical sounds to the subs. The HPF on a channel at 160 could still be producing some unwanted 80-120 Hz mud. Just my thoughts on it, still early on in my live sound career so I may change my mind. Great points to bring up!
Thanks for weighing in here, Steve! Do the speakers downstream of your desk have any built in DSP? Or does it all need to happen at the desk?
@@MichaelCurtisAudio it depends on the gig. Going into venues, yes. Playing private parties/weddings where we bring our PA, it’s all happening at the desk.
@@drumskentala I would just make sure you're not "doubling up" on your processing with high and low pass filters for your mains and subs respectively. For instance, a QSC KW181 already has a low pass filter on it. Not saying that you could add another to reduce overlap, but just check how your mains would interact with those speakers first!
@@MichaelCurtisAudio Right on. Good guess I’m what I’m using for private events lol. I do find that in a lot of smaller room 90-120 Hz coming from the subs can be a bit overwhelming. Would you be wary of that because that could wind up killing too much frequency and it would make the whole rig out of balance and missing certain frequencies?
@@drumskentala If you feel that there's a buildup at 90-120Hz by all means use EQ to help tame it. I would just personally reach for a parametric filter first.
Grab your sub matrix input from the sub aux send and you’re good to go. It’s the FOH engineer’s choice to either use speaker management or dedicated sub feed, but understanding why you’re doing it one way or the other is equally important.
Like you said, lots of ways to manage LF and that's definitely a valid approach.
Referring to how you talked about using a matrix for your fills. What would be the benefit of using a matrix over using an aux in post? Wouldn’t an aux send in post have the same effect in terms of levels following the LR and getting the same mix?
Great question. With an aux I would not be able to send me Main LR to it as an input source. The LR on most desks can only flow "downstream" to a matrix.
Furthermore, if I apply any master bus processing to main mix and the fills were on an aux, then my fill speakers wouldn't have my master bus processing.
I 5hibj many if us want our pieces featured in movies and stuff which is why it's mixed like sound track stuff. We use analog for the most part but post in digital but the end result is usually more sound track sound track which sounds better when it's played in a stadium as background music or something since it's already pre mixed plug and play.
Dave Rat would like a word... lol jokes aside.. all valid points, especially the part about it being uncorrelated with a stereo recording/stream/ etc. However theatre world where you have a million different speakers all over the place, correlation takes a bit of back seat when you have time to rehearse and program a console for 2 weeks and then aux fed subs are way more common. Great video as always!
Thanks, man! I'd love to have a conversation with Dave Rat about it. He's a brilliant dude and I think it'd b a fun talk.
@@MichaelCurtisAudioyeah ... Dave has a video and essentially he says noise is the reason he insists on aux fed subs ... Such as the noise that comes from gusts of air from instruments - say hi hat - that aren't designed to create low freq sounds. th-cam.com/video/hpFK1XOZuUg/w-d-xo.html. I don't understand enough about matrix mix to understand your approach ... But I'm up for the learning!
Would love to see a video on the use cases for a FOH reference mic. Generally, I understand it helps you get a sense for how your direct mix translates to the room, but are there specific things you are looking for in the signal? What is your preferred mic, and how do you decide where to place it?
When I use a mic at FOH it's to gauge SPL and also have a look at a few other graphs, mainly spectrogram and RTA. I use the dual-channel functionality of my analyzer during tuning, but single channel during show.
@@MichaelCurtisAudio Thanks for the response! This made it clear I need to develop a more robust metering system. During tuning, are you typically looking to achieve a "flat" response from your system? Or are there cases in which you may want the output transfer function to be nonlinear? I have usually taken this on a case-by-case basis (also primarily going by ear). I am wondering if I should get in the habit of staying flatter, especially in the balance between subs and mains. As you alluded to in this video, these types of nonlinearities can force you to think as both a system tech and mix engineer simultaneously.
@@nickwarren131 The "target curve" I end up using and staying with most often is from Michael Lawrence, a world class systems engineer. He uses it for the large scale systems he's tuning for musical performing acts. There's a -2dB drop off in high frequencies from 1kHz up to 16kHz. Think of it as a very broad shelf. Then for low end, starting at 300Hz, there's a fairly steep slope that goes +15dB up at 50Hz. So, the system is "flat-ish" from 300Hz on up, but then has a generous low end up to get some meat.
I came across this video because we decided to move from the Matrix sub feed and go to an Aux sub feed. I don't find that it will be any more complex than doing a stage monitor mix from the FOH console and we will be using less channels in the sub mix.
I didn't understand your comments about the stream feed being affected. Are you using a matrix to feed your stream or an aux?
Good video. I'll see how this works for us this weekend.
Thanks! My point about the stream feed is that if you're mixing subs on an aux that's yet another variable to your low end. So, it may feel "right" in the room, but since the low end is treated differently than the mains, it's hard to match that to your stream feed if you're pulling double duty.
also wont changing sub woofer level AKA aux fed subs change the acoustic crossover point?
Same thing with Matrix fed subs, but yes that will change. Not a dealbreaker in my opinion, though.
Hi Michael, could you indicate a link or simulate two diferent size speakers SPL map (6" and 20", for example) at same frequency and intensity? This is for academical purposes. It would be very interesting to see how speaker size affects SPL using same conditions.
This may sound simplistic and insulting, but it's not meant to be.
Sound is the movement of air. How much air you can move determines the amplitude (perceived volume) of your waveform. You're 20" speaker has to much mass to push and pull at 2000 cycles per second. Likewise, a 6" driver just doesn't have enough surface area to produce the same amplitude of wave at low frequencies.
I hope that helped.
Michael, regarding your recent email where you stated that people said you were 'divisive and your tone was arrogant' in this video... and you're taking it down at midnight tonight. This is my response:
"My husband and I just watched this so called divisive and arrogant video... what are you referring to, specifically?!? There was NO attitude from you. ... you sounded knowledgeable, concise and even gave us a heads-up we may ' vehemently ' disagree. Dude- It's YOUR CHANNEL , your content and rightfully your opinion. Please don't take down an 8-month-old video with NO dislikes and over 300 likes. If someone is causing you grief because they got hurt feeling... they can unsubscribe or turn it off.
Respectfully, keep doing your thing. You weren't offensive at all! Don't worry so much about 10% of people who are never happy. Focus on the 90% who appreciate your work."
Anna
Michael, while I might not agree with you about not using Aux fed subs, I love your channel and the knowledge you share with all of us. AND I 100% agree with Anna. It's your channel, do and say what you want. We'll either follow and learn, or we'll reject your ideas and move on.
I for one, am here for the duration. Love your channel. Please keep up the awesome work you do and continue to share. The video you just posted a day or two ago about working that cooperate show, is priceless to me. Gave me SO MANY ideas to incorporate into my own prep work before a bigger show. Thank you! Thank you!
Blessings for a wonderful, event filled 2023!!
Thanks for the support, Anna.
Thanks for the support and for sticking around for the long haul Joel!
Great points.
This video made me subscribe to your channel. Excellent and clear explanations.
Thank you so much, Clay!
It never even occurred to me to run the subs out an aux channel. I just use the sub out of my FOH EQ, and adjust the LF channels at the mixer as needed. I'll give your approach a try though.
In your example, Matrix 4 feeds the sub.
Im assuming you are simply selecting LR main fader, choosing sends and raising Matrix 4 fader to unity.
How is X32 summing that to mono from LR feed?
That's exactly it! You can also do it from the "sends" tab when you select your LR fader, then use the encoder on the bottom of the screen to send that to Matrix 4. The X32 automatically sums down a stereo source to mono when sending it to a mono destination.
Can you recommend an ideal setup for a DJ? I only have my mixing console with XLR outs to the amp. A lot of DJs are adding external mixers for more inputs and better control of the mics. They say it sounds better too. I'm wondering if thats really needed for better sub control?
I'd say you can get appropriate control from just a single console.
I'm no acoustical engineer, and I'm the first to admit I'm no live mixing virtuoso--but riddle me this: what's the functional difference between your preferred method (feeding a subs matrix with the LR buss signal) and feeding a subs matrix with signals from groups? Sure, you miss out on whatever processing is on the LR buss, and you may need to make a delay compensation if you use latent processing. I'm already a fan of using drum and vocal busses, and if I made an "All Instruments" or "Video World/BGM" buss, couldn't I just send each of these busses to the subwoofers at -0dB, and have nearly the same result as your method? With, I might add, the added ability to remove any of these busses from the sub feed by muting its send? I think this "subs or no subs" method splits the difference nicely between the benefits of complete sub removal on problem signals and the downsides of aux-feeding that you describe in the video.
And to preempt your inevitable question of why I would want to go about this bass-ackwards way: I'd like to be able to try something like your method in a venue which has defaulted to aux-fed subs.
Hey, Tim. The biggest reason for me personally is that running a matrix (or letting the system processor do everything and simply feeding it my LR mix, which is my preferred method) makes a clear divide between my console is for mixing, the processing or matrices are for wrangling the PA.
When I'm choosing what's going to the subs or not, even if the send levels are at unity, I'm having to think both like a mix engineer and a systems engineer at the same time. Feeding it my LR mix saves me subgroups/buses, keeps all my processing in one place, and I can trust my board mix will sound great since I'm not having to think about the LF in my mix vs the house system, assuming my mix is great ; )
Curious what slopes you run your high pass at on your vocal mics?
Usually second order butterworth. Sometimes third or fourth order.
What if you mixer does not have Matrices? Behringer xAir 12
Thanks for sharing. This was really helpful!
You got it!
Even the matrix outs aren't much use to you. If you're 60m away at FOH on a festival gig what the point of having control of the infill level when there's no chance you'll ever hear them, you really just have to trust that the System tech has it all properly set up. Also turning the sub level up or down on the matrix can be though of the same as having access to to the system processor and turning the subs up or down on there. Doing this after its been time aligned is then screwing the timing up as is inadvertently shifting the crossover point higher or lower as you adjust the level of the subs relative to the mains. For me LR all the way straight into the system processor.
I'm operating on a much smaller scale than you. But I have found that my sound is much better if I run subs from an aux. HPFs do work to some extent but have a slope. And mics and acoustic guitars do generate low freq signals which are just junk. My tops can do all the LF needed by any vocal mic or acoustic guitar. So I am very particular about what I let into my subs: usually kick drum and bass ONLY .... sometimes also keys if there is no bass. My bottom end sounds much cleaner when I do it this way, so regardless of any theoretical discussion, I will keep doing it this way, and I'll keep recommending it for people to try. In the end, whatever works for you. Aux subs work very well for me.
I'm glad your setup gets you the results you're after! By all means keep going with it.
For me it really depends on the system and how your console brand implements auxes and matrixes. I find, specifically on digico consoles, running subs as a matrix that you can choose weather or not a given channel sends is nice. Some systems implement this differently, and I find using whatever gives me the most control over the sound is generally the best to use. If I’m on a large PA with delay subs and massive delay line arrays as fills, aux subs may not give me the even sound across the audience that’s desired. It’s just a tool that’s sometimes helpful and sometimes not :) love the content btw
Thanks for sharing!
I would agree. If I am in an arena with multiple hangs, Each zone of PA is treated as it's own. For your example of large PA with delays and out fills, I may have the Main L/R zones with sub on aux, where my delays and out hangs are run full range.
Again, like you said, different rooms and different gear builds, have to be treated with flexibility. Last month, I have had to build a show with a mono-block of subs in front of the stage, a regular point source set-up, an inline cardioid subs, and once a di-pole cardioid set-up. 3 weeks, same band, 4 different sub set-ups.
Again, good job to Michael Curtis for initiating this dialog. And good job to you for bringing more information to the discussion.
Reason #4 is a very good point that I sometimes forget, well said.
I sometimes have to use an analog console, with fixed slope and frequency for HPF. In this case I would argue in favor of using an aux.
Nevertheless, thank you for your well argued insights!
Yes, for that specific analog use case with a limited toolset an aux can definitely be helpful!
You probably don’t remember but several years back at KPC you and I actually had a conversation about this exact thing. I hate mixing separate to the subs for all of the reasons you give!
I do!
Really valuable information to consider about system and mixing workflow. I think it may be great advice for beginner engineers/techs. I just have a few questions that I need clarification on.
1. Can’t you utilize bus processing separately and mix levels on DCAs for instruments? I do this a lot.
2. Using a hpf on channels and lpf on the system how much different is this than using a crossover? If you are streaming with subs on aux, it always makes sense to reach for eq as well for tonal changes unless you’re compensating for serious abnormalities live.
3. Transfer function point is valid, but if you keep the system close to full range and use the subs as low end enhancement. Would this allow your full range PA mix to be sent to the transfer function? It seems viable to feel out the low end needs based on the event/crowd engagement, etc.
Thoughts?
Hey, Leif. Great points here.
1. I'm not quite sure the routing you're trying to get across here. Buses on most desks can't be routed to another bus, so the aux doesn't get the processing?
2. A hpf on a channel is very different in that it is much farther upstream. All monitor sends, PGM feed sends, main LR sends, etc. would be affected by that. And I'm not saying it's impossible to have the aux make a sensible balance of low end vs the stream, but I do think it introduces another unnecessary variable.
3. If I'm on a system where the tops barely get below 80Hz, then the subs are more than just low end enhancement. It's a good idea in theory to use the subs more like an LFE channel, but on the shows I'm on they're treated like an extension of the whole PA, not for effect.
1. Ah, right. I got turned around in my thoughts about parallel processing vs inline bus processing. It wouldn’t make sense to send the bus with HF content to the matrix either. The engineers I’ve worked with process the kick and toms individually and only send bus processing to the tops (paying attention to phase coherence). Then mix level on the DCAs, but this does require extra brainwork in routing and mix decisions.
2. You’re absolutely right in saying the methods of system design/routing will be more work to account for in your design/mixing.
3. I understand clearly now, not sure if I missed this in your video. It is important that your subs feel cohesive to the entire system with similar processing.
I think your information can be quite valuable in setup especially with a similar system and managing the entire show smoothly.
Thanks for this video! I think I stop using subs on aux for awhile and see how it goes. I was always afraid of bad stuff getting into the sub, but I'll try your EQ strategy for vocals with the low cut, and two high shelves. Do you have some other recommendations for how to EQ guitars, bass and drums? I need to learn more about using EQ for better sound. Just looking around your channel now.
Thanks a lot! I have a free PDF in my Audio Toolkit called the 9 EQ Pivot Points that I think would be helpful for you when it comes to EQ.
Although there are specific techniques and frames of mind for each instrument when using EQ, having these "macro" ways of thinking about each part of the frequency spectrum applies to all sources.
@@MichaelCurtisAudio I've been playing around with not using the aux-fed subs some. One thing I noticed is there is definitely *some* vocal content that is going through the sub even if I use a 160hz hpf. i guess it's not possible to completely eliminate the vocals, etc. from the sub with this method, just reduce them? that may not be a big deal of course. If I'm applying the hpf and maybe some low shelves to eliminate more of certain channels from the sub, will live performers be upset that their monitors make their guitars or vocals sound too thin?
I'm wondering if it really makes much of a difference for my small setup whether I use aux-fed subs or not. I usually just have 1 sub and 2 tops at gigs (crossover is 100 Hz b/w sub and tops.) Is the phase issue really that big of a deal if I have the sub adjusted independently of the mains in that case? I never do a live stream, so I could see that being an issue with the aux-fed method, as you indicate.
Is there a difference between increasing or decreasing the volume of the sub through the aux and doing it through turning the volume control on the sub up or down?
i do a full range setup and depending on the venue too if there are lots of low energy then i adjust my hpf either from 120 to 200 just depends on the venue, but im just doing small events not big events
So, you always run your subs in mono (unless there is a specific demand for stereo subs, I guess)? Best regards from Sweden.
In live sound subs are generally driven mono, multi channel only in very specific use cases :)