So, 2 questions. 1) Distance. Your arrival time at the mic is not going to be instantaneous right? And 2) if your fill is 90 degrees off to one side, (as I've seen more times than not on bigger stages) do you get a 90 degree phase shift in the mic (plus whatever time delay you have)?
As far as arrival time the kick drum is two or three feet from the drummer's gut so having the drum fill two or three feet from the drummer's gut gives you perfect timing. And you can be a foot or two off or have a few milliseconds of latency in a digital console and it won't matter much. If the arrival times are off by 2 ft then to calculate that divide the speed of sound by two and you get 560 Hertz. Where the sound will be one full wavelength off and it'll be a half a wavelength off at 280 Hertz. Since polarity issues are more audible with low frequencies a couple feet is no big deal. As far as 90° off-axis monitors that's a flawed assumption. The direction that a speaker or drum head is moving is a bit misleading. I use that or reference that to make a point and help people understand but what is actually happening is the monitor is either creating an initial negative pressure wave or a positive pressure wave. The kick drum is creating an initial negative pressure wave on the drummer side of it and an initial positive pressure wave on the audience side because it has somewhat of a figure eight polar pattern like a figure eight mic. Stage monitors have more of an Omni or cardioid polar pattern wherein the sound radiated in all directions is the same polarity whether you're in front of it behind it or alongside it. So it doesn't matter which way the monitor is pointing it could be pointing away from the drummer it's still putting out a positive pressure wave in the low frequencies in all directions. The kick drum and other drums are different and more like an open back guitar cabinet or an open back speaker where it outputs opposing polarities in front and behind the drum heads
I've been looking at phase problems on the FOH side for some time now, why I never asked myself these phase issue on stage ? It's crazy ! Now, you've screwed up my mind forever ! I'll never be able to ignore this step again. I can't wait for my next show...😁 Thanks for your explanation, you are a goldmine !
One thing a lot of guys also forget is the polarity AND DELAY usage when using Kick IN and Kick OUT. Very important to use a small amount of input delay on the Kick In to maximize the Kick sound to make sure it is in time with the Kick Out.
Yes though it's somewhat depends on the sound you want. If you delay the out mic to the in mic, you will be time aligning for the beater head. If you slightly delay the inner mic to the outer mic, then you will be time aligning the focus onto the resonant head. So you're kind of selecting between punchy and fluffy
@@DaveRathey man awesome videos and explanations. My only question right now is how do you delay the out kick to the in kick? The out kick is inherently receiving the sound later, so how can you delay it to the in kick? Are you just delaying the out kick slightly to move the positive/negatives further apart to avoid cancellation?
Well said! Diagrams are so helpful! Took awhile to learn this concept with kick/bass in real world- this was so concise and will save others lots of time. Thanks for sharing the wisdom!
Thanks for this Dave! Band I'm touring with are all on IEMs with no wedges but what you said about the vocals on IEMs was really interesting and will definitely try it out
The small detail to never trust that mics and speakers are always wired correctly is gold advice. I'll admit that sometimes I assume things are built correctly and set polarity based on that detail. Thank you for the advice!
Yes, I have actually found mics made by manufacturers incorrectly. The entire Electovoice NDYM308 and 408 line was initially released out of polarity. Then fixed after an awkward call from me to their tech support. Also all the in-ears made by JH Audio are made out of polarity as well as old JBL speakers for decades till they finally switched.
Hey Dave I was a member since the beginning but TH-cam deleted my channel so now I have to start from scratch. In the past we've had discussions about impedance and a few other things. Feels good to be back, supporting you, and getting the inside scoop on whqt you're up to! Also I just used my new xlr sniffer for the first time this weekend at two gigs. Every cable I grabbed went into your cable tester first before being deployed. 😎
Well, I’m off to rewire the positive/negative pins on all the kick mics….But in all seriousness I’m excited to try this for real at the next rehearsal. Not sure if the space is large enough to discern any difference, though, with all the sound bouncing and clashing everywhere. But next sound check at a show, it’s getting tried as well. Great stuff, brother.
@@DaveRatWell, sound check went great. Our drum fill is a built off two sends. One is kick and bass into a sub, the other is all vox and occasionally on bigger stages a guitar cab that’s far away. Polarity reversed the kick signal to the drummers sub. Was able to cut the level pretty significantly, down to something that seemed much more reasonable and in line with what the other stuff was sitting at. And I may just be imagining it, but it felt a lot more “tame” to work with (best description I’ve got). I guess because I wasn’t right up against clipping and diming the fader out constantly. But either way, big help so far. Thanks again, brother! That’s exactly why you’re my go to source of info.
Dave, last year I did a series of shows with a band and tried something different from past years that is similar to this topic. I had all the mics correctly wired for Pin 2 positive. The stage monitor amp has a switch that reverses the polarity on its inputs, so I engaged that button. This resulted in Pin 3 being positive for the monitors. Having this setup, I was able to gain more volume and practically no feedback during the show. You could still get feedback if you turned it up WAY loud, but I found no reason to set it that way. Mind you, this was just an experiment and it worked out great for me.
Very cool. The thing to watch out for by switching the polarity of the amp rather than specific channels is that it will make some things polarity correct but make other things incorrect
Basically, a setup of about 10 mics (all SM58's, except for 1 AKG C1000S). The band is dixieland jazz. The drums were not mic'ed, as they carried loud enough in the venue to warrant that configuration. Everything into a MixWizard 16:2 and then patched into the venue p.a. system.
Few drummers are still using giant wedges as monitors, and the few that do usually have them coming at them from the sides rather than from behind. The majority these days are using IE monitors.
What's important to know is that it makes no difference whether the drum fill is on the side or behind or even next to the kick, the pressure wave is the same. If the drum head is moving away from the drummer you want the speaker moving away from the drummer behind in front on top makes no difference. Also, I don't doubt that many of the drummers you work with are relying on any ears and do not use drum subs. But it's important to know that is not the case with many of the larger bands and artists and many musicians. And just because some drummers don't use drum fills, that is not a good reason to bypass understanding this important concept and it is important to know that this concept also applies to drummers using in ears! Having the in-ears in polarity with the acoustic output of the drum from the drummer's perspective and position will give you improved results and happier drummers. As the summation of the acoustic sound and the in-ears will be complementary rather than destructive. I
This is one of the most useful videos I think I've ever watched. I just run a bar PA, 2 subs, 2 tops, 3 monitors and 1 center fill when needed. Makes a ton of sense to flip the kick drum, I guess with my bass amp, since I don't run it in my wedge, I would just be competing with the subs? I don't mic it, I run through a IR loaded DI box, so I guess I would want the amp to be the same polarity as my subs since they radiate outward kind of omni directional?
This checks out with what I’ve always found! I wargame polarities for drum kits in IEMs while actually hitting the drums myself sitting there behind the kit and setting them so they sound best for the drummer. Also agree on vocal mic polarity! I discovered a long time ago that various IEM, mic AND even peoples hearing seem to have different polarity. I always ask a singer to listen to both ways and am sometimes surprised by the preference. I have done this even with the highest level artists. I get some people who say they ‘don’t understand audio’ and ‘just want me to pick’. They can instantly tell what sounds better to them when they take a second to listen. With regards to vocal mic latency, with digital systems we are approaching critical mass IMHO. In my rig i have Sennheiser D6000 mics (2ms), Avid S6L (2ms with no plugins), and Wisycom IEMs (1.1ms on Analog input and their hidden Lower Latency mode). In my testing latency was worse on Wisycom going to the AES input - presumable because the non defeatable SRC is slower than AD/DA conversion.
I take it you mix monitors. As a FOH engineer, I want the artist to hear exactly how they present to the mic, with no EQ, no compression, etc. They then adjust mic technique, tone of voice, etc which gives us the best product. Most monitor engineers I know want to work counter to this and give them a better than reality sound. I feel like every performer should have themselves, whether it be instrument or vocal exactly how they are presenting it so they can adjust their performance. Of course everyone else in their mix should be as dialed in as possible. Tune the vocals for the rest if you can so the singer can adjust to in tune harmonies, for example. Compress the others so they can hear how wildly they are with mic technique in comparison. This way everyone gives a better performance and we don’t have to rely so much on the outboard. It always sounds better when they just do it right naturally whether its being in tune, compression, or EQ. What do you think?
@@tigeraudio I've been a touring monitor engineer exclusively since 2002. I give my clients whatever they ask for if they ask for it. If an artist wants a specific sound in their monitors, it is my job to provide it, not inflict my personal taste on that person. And you'll definitely never hear me say "The FOH guy told me I can't EQ your vocal and you should sing better." I have had a string of very long contracts over the years (12 years with my current artist) thanks to that willingness to serve the desires of my clients. If asked my preference, I prefer that the musician provide to me the sound they would like reproduced so I can deliver it back to them unaffected. We spend a lot of time tuning drums, selecting vocal mics, and tweaking amp modelers and keyboard presets to achieve that. However, I am not so hard headed that I will not use equalization if it better serves the sound of the source. I rarely look at the picture of an equalizer while adjusting it, rather I turn knobs until it sounds right. If the picture looks like a mountain range to get the right sound, I simply do not care. Are you insinuating that adjusting to polarity of microphones for the best sound quality in the monitors is providing better sound quality than reality and a detriment to the performance???
@@cgtbrad I am not implying anything regarding anything. Strictly academic conversation. Obviously you give them whatever they ask for. I didn’t say anything about polarity. I was asking for your observations. I see a lot of compression and even tuning used on ears and what you get for a source is getting worse and worse. I think when we had less technology available to us, we had better performances. In the studio, we never did anything to their voices and they would hear themselves exactly how they sounded. I think that was the point of IEMs. I was only there for about 2 years before the recording “business" started to fold as people started to be able to buy their own gear for the cost of a record. Les Paul and Mary Ford used to watch the meters on the tape machine while singing before compressors existed.
@@tigeraudio I’m not aware of any practical way to tune vocals for artists in their IEMs. As far as I know the Waves and Antares plug-ins have too much latency for that and I think it would be really weird to sing while chasing auto-tune in their monitors. I compress very lightly with a limiter only for yelling between songs, and use dynamic EQ to taste and for de-essing.
I spend a lot of time on this. As would any live recordist, I have the luxury of printing checks and rehearsals, conducting tests prior to show. My discovery lets me establish a relationship between the multiple mics and multiple sources in those mics, and I find it always helpful to my live mix. I prefer + pressure on BD and snare, that there is a tonal difference, so I use that as my starting point and treat other parts of the kit mics as groups. I usually find real progress aligning OHs to snare and very small delay in both OHs can help. In post, I often nudge the OHs backwards and the benefit to snare sound can be very real. Once I solve that relationship, hats and toms are usually left as-is. I know the circumstances are quite different for my purposes than they are for you in live sound, but the principles are the same and I’m really happy to see your discussion of them here, Dave.
Very cool and paying attention to the details can make the difference between good and great. You have the luxury in recording to choose whether or not the kick drum is a positive or negative pressure. Though if your speakers are linear it shouldn't matter and theoretically if you hear a difference between an initial positive pressure and negative pressure it should be just nonlinearities in your listening devices. Beyond that, with a drum fill and the actual drum and combining those two signals, The kick drum creates an initial acoustic negative pressure wave from the drummers perspective that can't be altered with a switch. So whether we want a positive or negative pressure wave doesn't matter what matters is matching the drum fill to the acoustic pressure wave of the kick drum for the drummer sitting equidistant between the kick drum and the drum fill. And super cool that you line all that up! I have gone deeply down that rabbit hole and achieved desirable results that are repeatable by aligning every mic on stage
@@DaveRat Actually, the pressure polarity does matter on a bass drum on every speaker, earphone, etc I’ve ever tried. BD is a special case, particularly as we use it in popular music, in having the fastest and deepest decay of far less than even one single primary frequency wave. If you’ll indulge my assumption, I believe that’s the reason I’ve never NOT been able to hear the difference. Interestingly, that difference is less apparent soloed than in a mix. And yes, I agree with all you’ve explained regarding the drummer and your speakers.
@@DaveRat Key to my observations about the BD specifically is apparent looking at the waveform, which I do a lot. (Perhaps to my detriment?). The point remains that the + pressure is clearly an order of magnitude louder than even the - pressure half of the first complete waveform at the fundamental frequency. I take this, right or wrong, to mean it has two distinct sounds and I believe that is what I’m hearing when I choose the pressure at my monitors.
@artysanmobile Yes that makes sense, absolute polarity which would be most apparent if the drum is soloed, should not make a difference unless there's non-linearities in the transducer recreating the sound. Theoretically nonlinearities in our eardrum and hearing could come into play as well but whether the initial pulse is negative or positive is either irrelevant or borderline irrelevant. The way that the kick drum mic picks up the kick drum and the other instruments versus the mics picking up the other instruments and their polarity and the summation of all those signals bleeding into each other, is highly probable to be audible and impact the sound audibly
Very interesting video. But here is food for thought we as front of house operators always like when Kid drum is coupled and tightly locked with bass guitar when the drummer hits the kick, and we the nonstick side of the kick the mic creates a positive rise in the AC voltage, when the bass player hits the string, he creates a positive rise in the voltage. So by switching the polarity won’t induce an uncoupling effect between the kick and the bass guitar.?
Polarity between signals that are not correlated or somehow related to the same source generating them are not impacted by polarity. Polarity matters when a signal is combined with another version of the same signal. If the bass player plucks the string upward or downward, the polarity should be reversed, right? Or pulls on a string vs hits it with their thumb, those are opposite motions. Which one is correct with the kick? The reason polarity matters for the drum fullia the 2 versions of the kick sound. The natural sound of the kick and the reproduced sound of the kick For the bass player, whatatters is the sound of the bass rig and the sound of the bass in the mons combining in polarity. Polarity is a relative concept. There is nothing to relate when the signals are unrelated, even if they are playing the same song and in time, they are not polarity relat d when coming from differing instruments.
I can see how inverse polarity in FOH works better for on stage as the kick drum moving out would make the FOH subs move in reverse thus keeping the positive pressure onstage and not cancelling out the kick for the musicians. But how does this affect the audience in small to medium venues? Because normally the audience could hear the initial positive pressure from the kick but with it phase reversed in the FOH you now have a reverse polarity kick in the subs couple with a positive waveform from the kick drum itself. 🤔 So is it more important for the kick to be in phase for the musicians on stage or the audience who is there to hear the band?🤔 I heard once that everything we do in professional audio is based on a compromise since everything in audio is theory and there are no laws of audio. Love your videos brother! It's all about helping each other learn how to provide a better experience for our audiences. Because bad audio at a concert just makes everyone sad. 🤘
When two sounds sources are heard at approximately equal volume and approximately equal distance polarity matters a lot. So from the drummer's perspective where the kick drum is loud for the drummer and the drum fill is also loud having the drum fill in polarity with the kick drum is important for the drummer. From the singers perspective who is on the opposite side of the kick drum and getting a different polarity from the kick drum The kick drum and drum fill will tend to cancel out if they're the correct polarity for the drummer. But if the rest of the monitor is the same polarity as the drum fill all of the monitors will be in polarity with each other and the acoustic kick sound will be out of polarity with the rest of the monitor rig for everybody but the drummer this is a concession that's okay. The monitor rig should be the same polarity as the main PA. So if the kick drum is polarity reversed in the monitor rig to make it correct for the drummer then the kick drum should also be polarity reversed in the main PA. This means that the main PA and monitor rig will be the same polarity as each other and anyone standing on the edge of stage halfway between the monitor rig and the main PA will get a summation rather than cancellation. The main PA and subs will be less likely to suck all the power out of the monitor rig which is what happens if the any instruments or the entire monitor rig is out of polarity with the main PA So the driving factor in this is the one person that is equidistant from the acoustic kick and the drum fill which is the drummer and wants to kick them polarity is established everything else just follows
@@DaveRat Again with an amazing explanation! That makes allot of sense! Thank you for all of your insight; it is truly helping those of the younger generation following behind you. 🤘
Great explanation but I think nowadays one must consider processing delays, too, because way too often the whole loop isn't fully analog and a single AD-DA conversion may cause enough latency to cause destructive interference thanks to latency even if your polarity is correct in theory. If you have unknown latency in the system, the best you can do is to have constant volume source (might be a bit hard for human controlled hits but doable with a good drummer) and try both ways for polarity and choose whatever results in higher reading in dB-meter from the position where you want to hear the monitor.
Latency of 1 to 4 milliseconds is just like moving the drum fill 1 to 4 ft farther away. Having a couple milliseconds latency and putting the drum fill a little closer to the drummer solves it easily. Polarity remains The dominant issue for latencies under four milliseconds. Above that polarity still matters but it has less of a positive impact when you get it right
@@DaveRat 4 millisecond latency causes full destructive interference for 125 Hz frequency for the position half-way between two audio sources, 1 ms latency causes full destructive interference for 500 Hz frequency at the same position even when the audio is played in correct phase. This is no different from room modes or boundary interference.
Yeah that's true, and getting the drum fill perfectly distance and time aligned to the drummer's gut from the drum head is optimal. And also the summations are pretty messy and the resonant head of the kick drum tends to be late and add the equivalent of some latency itself. What I found is that with drum fill fairly close to the drummer, polarity has a more audible impact than altering the latency two or three milliseconds Would love to any result from testing or messing around with it if you get the chance to do so
Microphones are wired backwards compared to a speaker. So if you ever use the speaker as a microphone you have to flip the polarity. Or turn the speaker around and use the magnet as the face.
@@zmarasigan9788 yes. but be careful with the signal level. It’s a big 10 inch diaphragm with a big coil and a big magnet. I would test it on something cheap first or use a meter to measure the output. some people wire a - 20 db pad into the circuit.
It's not that straight forward. Mics are wired backwards polarity to creat a correct signal. If you wire a speaker correct polarity and use it as a mic, the output polarity will be reversed. Positive voltage on positive terminal moves speaker outward. Positive pressure on speaker moves speaker inward and creates negative voltage on positive terminal
A positive pressure wave pushes the mic diaphragm inward. On a properly wired mic, the mic dia moving inward created a positive voltage on pin2 of the XLR. On a properly wired system, a positive voltage on pin 2 moves the speakers outward. Positive pressure from the mouth, positive pressure from the speaker. With a properly wired system, wedges are in polarity with the singer voice and in polarity with all signals presented. The issue with the kick is the mic is mic'ing the out of polarity side of the kick
With a mic in the kick, im leaning towards using the front head as my Starting point for polarity reference, whith the idea that the driven head will contribute to the sound more than the resonate head or shell, and possibly more than the reso head and shell combined. Also, and not that it makes a difference for frequencys lower than a 1/4 wavelength than the longest side of the mic but directionally will come into play a little bit with the mic, I presume. I'm here to learn like most of y'all, so let me know if im making any incorrect assumptions.
Does this polarity concept apply to vocal mics also? I recently found myself in a space constrained situation where in order to make everyone fit, the vocal mics were placed slightly in front of the mains. Feedback was obviously a huge issue. Had I had a polarity switch and put the mic signal out of phase with the main mix, would feedback likelihood have been reduced?
Polarity on vocal mic vs in ears matters and I did a few vids on that. As far as mains or mons vs vocal mic, yes it matters for the singer but won't alter feedback much. It will alter the way the singer hears the sound.
So with vocal and guitar mics the air pressure goes in to the mic capsule. Does this mean they are usually mixed off phase of the drums, or are those usually swapped as well? I'm guessing there is no "standard" for DIs?
Polarity is a relative term. A sound source itself like kick or voice or guitar is neither in or out of polarity by itself. But, when comparing two versions of the same sound like the front or back of a drum, the sound of a voice and that same voice being mic'ed and amplified and coming out of a speaker, you now have many factors involved when combining or adding those two versions. Things like time offsets, eq differentials, phase shifts and polarity will have impacts on how well or poorly they can be recombined. Polarity is probably has the most dramatic impact. Because if polarity is reversed on one of the two versions of the same signal being recombined, then total and complete cancellation can occur. So a guitar speaker or a voice or any sound source has a sound radiating out of it and if you put a mic on it and that sound comes out of a monitor speaker then that is another version of that sound source. With a properly wired microphone and system the natural sound or original sound will be in-polarity with the sound coming out of the monitor speaker. If for some reason The amplifier where the monitor speaker or the microphone has a polarity of reverse, then the two versions of the signal will be very destructive with each other when listening to both at the same time assuming that the other factors like time offset phase and EQ differentials are not significant.
Dave, would the polarity of similar sources make a difference for front of house if you’re not using a separate monitor console? Would having the kick and bass guitar out of phase cause undesired cancellation?
If you're from the house system is in polarity with your monitor system which it should be, then any polarity versus that you do in the monitor rig should also be done in front of house. Otherwise you will get cancellations between monitors in front of house that may be audible in places that are equidistant from the monitors in front of the house
Reversing polarity is a great idea, isn’t there is one more way to achieve similar results on digital consoles by inserting input delay to the input channels it will give the same results in fact more accurate in some cases than switching polarity? Great video thanks for sharing this with the world 🙏🏽❤️
Hmmm. Not exactly. Adding delay can align the kick with other drums, but just like delay can't fix your left studio monitor if it's wired out of polarity with your right monitor, delay won't fix kick out of polarity with drumfill from the drummers perspective
Dave you say you use the same polarity on the kit for monitors and front of house? With kick for example would flipping polarity not make the low end more out of phase with the main PA?
If your pa, your subs and monitors are ported boxes or horn loaded or sealed, they will put out the same polarity pressure wave in front and behind the enclosures. If you rec polarity on the kick so the drum fill creates an initial negative pressure wave to align with the acoustic negative pressure wave created by the beater hitting the kick head, then the kick sent to side fills and wedges would also create an initial negative pressure wave. So you would also want your main PA to create an initial negative pressure wave such that the money rig and the main PA are the same polarity. Any listener that is equidistant from the mons and mains or mons and subs or sid3fils and mains, would then hear summation of the mains/subs and mons/side fills. Flipping polarity in the mains or mons and not doing the same everywhere will cause cancellation between mains and mons and that is usually undesirable as the mains will tend to suck the LF power out of the monitor rig
@@DaveRat thanks for the detailed reply! I guess my thought was that from the perspective of the audience, that initial pressure wave would be positive, or opposite to what the drummer experiences, but sounds like the overall effect of mons being coherent with pa is more important. Anyway, next time I get a chance I'm going to try this out! Ps. Just found your channel, love the down to earth yet enthusiastic vibe. It reminds me that it can be fun to learn and experiment with your work 😎
Cool cool and thank you. Yeah, can be confusing as it's not really the direction of motion but rather it is whether the pressure wave is positive or negative. For a speaker in a cabinet the pressure wave is the same in front and behind. For a kick from, open back speaker cabinet or any other sound source with a figure 8 radiation pattern, the pressure wave behind is the opposite to the pressure wave in front
Having ambience mics of the musicians can hear the audience is desirable by many bands. As far as polarity reverse, that could reduce some low-end content and it's worth giving a listen to and see whether in polarity or out of polarity is preferred or sounds better.
ooooo... I wonder if placement relative to the edge of the cymbal matters drastically when micing cymbals.. the standard vibrational modes are way more complex than the fundamental modes of a drumhead- so the peaks and troughs are going to dispersed more 'randomly' across the cymbal. Have you found even anecdotally flipping polarity when micing bottom of cymbals really does gives better results??
No, cymbal polarity does not audible matter but mic polarity on the cybal can matter. Because low freqs from drums bleed into cymbal mics. If the mics are out of polarity, the drum bleed can cancel with other mics.this may be a good thing
Thank you, Dave! Your advice is very helpful. It makes perfect sense for monitoring. I have a question which leads to other questions. Does it matter for subwoofers (or other types of speaker in general) if the drivers move out first or in for better impact? How it differs with different types of subs or configurations? If that matters maybe it's better to use straight polarity of Kick In mic in FOH in most situations?
@@DaveRat yes, it's a good way to think about it. Perhaps I'm too specific here and need to clarify. We know that speakers are not ideal. Considering actual speaker cabinet in a space with real amplifier as a system that has it's limitations, does it performance differ on powerful transient material such as drums if it push air first or pull? I've played with polarity on single kick drum source and noted that my studio monitor reacted differently when I flipped signal's polarity. On headphones I can hear a difference too. It's subtle! Interesting to note that my preference on how kick sounds with different polarity on monitor vs headphones was opposite. In smaller venues where drums plays significant role acoustically it's more about sum of instrument with PA. Maybe on bigger setups where you not so dependant on that, it's not a bad idea to try and find in which way system reacts better? What's your experience in that regard?
You're talking about absolute polarity. And I don't believe anybody's definitively shown that it matters one way or the other. Psychologically we like to believe that something should push us before pulling but as far as physics is concerned it makes no difference whatsoever. Yes there are differences in speakers and nonlinearities between pushing and pulling. Whether those nonlinearities happen first or second may make a difference for specific speakers but that does not mean that we can hear the difference between a positive going or negative going initial waveform. It just means that we can hear nonlinearities in that specific speaker It's also quite probable that nonlinearities in our hearing itself may make positive going pulses sound slightly different than negative going pulses. So it may be possible to hear slight differentials between the two but as far as establishing whether we hear the nonlinearities first or second, I would be remiss to say one is better than the other. One can easily hear polarity differentials between two sources playing at the same time and one would be quite challenged I believe to determine whether a speaker's absolutely polarity is positive or negative when no other reference points are offered
How about the bottom of the snare mic, which picks up the kick, that's in front of the kick and behind the snare? I know I should probably try both ways, but what's the science behind it? I'm asking for clarification because bottom of snare mic I usually do not gate
Set the mic polarity to align with the dominant instrument that it is picking up. If kick in the snare bottom is a concern then put this near bottom might closer to this near bottom to reduce the issue
What if you mic the kick from the batter side? Would you still have to deal with polarity issues? I've noticed that doing this has cleared up alot of issues for us but I don't see anyone else doing this.
Yes making the beater side of the head, Will give you the opposite polarity of making the other side. It's a mystery as to why no one is doing it as a normal and obvious thing. I mean we see people hitting the polarity reverse on snare bottom when they mic the bottom of the snare. If you make the front and back of a kick drum you would naturally put a polarity verse on the back mic. It just seems quite obvious that when you mic The back side it should be polarity of verse and when you make the front side it should not. When I first figured this out I tested it over and over again and couldn't believe that something so logical and obvious was not common knowledge. Puzzling and also fun!
hi dave i have a wierd one got no phantom power working on but 2 channels even with the old mixer the same thing could it be the wiring under stage has a glitch ?? making it bypass? i have no polarity switch on a Behringer pmp 6000
@mikepruett1745 I designed a cool tester for exactly this kind of thing. They will test using Phantom power or the sender unit and you don't need both ends of the cable in the same spot. soundtools.com/cable-testers-page-ssxlr.html
In a situation like this do you time align the drum fill to match the distance from the kick drum to the drummer? I assume time alignment would be a big deal when dealing with phase alignment.
With analog putting the drumfill the same distance from the drummer chest as the kick is, can help summation. With digital, the drumfill typically can't be close enough as latency makes it farther As far as how much it matters, it matters most with low frequencies. And being within 1/4 wavelength is good. A 1/4 wavelength of 80 Hz is 3.5 feet. So +/- a f w feet from perfect alignment is all good
I see your diagram as if the monitor was behind the drummer. What if the monitor was 90degrees to their right or left side? Would it be the same or make a difference?
Yes it would be the same even if the monitor was pointed away from the drummer. Sealed back speakers and ported speakers will output the same polarity in all directions. But if you had a drum fill with an open back enclosure, then if the drum fill was pointed away it would be the reverse polarity as pointed towards you and if you were looking at the side of the drum fill you'd be in a cancellation area. My point is that most speakers with the exception of open back versions, output the same polarity in all directions so it doesn't really matter which way they point they're just louder in front
The for me is, is it the microphone out of polarity or the speaker? I usually flip the polarity on the drum fill output, not on the kick drum mic. Also, latency, specifically on digital consoles… a couple of milliseconds have a large effect in all these scenarios
Latency of 2ms just makes the drumfill a virtual 2 feet farther away. Flip drumfill polarity is fine but now all the drums like snare top and toms mic'ed from the top are out of polarity with the drumfill. So you need to push even more polarity switches.also the drum fill is now out of polarity with the rest of the stage mons, so bass sent to drum fill will be reversed from bass sent to wedges or sides.
I need more information on this. Possibly with electronic testing. Because the drum head moving forwards towards the audience should make the speaker move forwards towards the audience. He has it backwards. The microphone facing the front of the kick drum would actually naturally create a negative phase response
Mics are typically wired such that a pressure pushing on the diaphragm creates a positive voltage on pin2. A positive voltage on pin 2 should make a speaker move outward. So mic dia moves in means speaker moves out. But looking at it from a dir action of motion perspective is not ideal as typically a speaker in an enclosure readiates the same polarity pressure wave in front and behind whether it is pointed towards or away from you. The issue is that a kick drum has a different radiation pattern than most speakers in enclosures as a kick has more of a figure 8 radiation pattern. Where the polarity on the drummer side is reversed from the polarity on the audience side. If you want the kick to sum with the drumfill for the drummer, you need to polarity reverse the mic or drumfill. If you want the drumfill to be polarity correct for the single or audience, you would not polarity reverse it. Typically though, it is more important to have the drumfill sumwith the kick from the drummer perspective than to sum from the audience perspective. Looking at it from a
Getting the polarity between your monitor rig in front of a house rig is important as well. I did a video a while back on that but I don't remember what it's called. The concept of reversing polarity of the monitor rig because the wedges are pointed the opposite direction is incorrect. You will want the polarity of the main PA to be the same polarity as the monitor system If the kick drum is polarity versus in the monitor rig then you will want to polarity reverse it in the main PA as well
No, bothe moving away and then both moving towards is in polarity. But towards and away are misleading as it implies that pointing in a diff direction will alter polarity. Think of " creating a positive or negative pressure wave" and are they both doing the same thing or opposite things. Same is in polarity
Yes you can just flip the polarity of the monitor and that will fix the kick but then your snare top will be out of polarity and you're near bottom will be in polarity and your toms will be out of polarity if you mic the top and in polarity if you might come from behind so it just flips all the things. But what you really want to achieve is to make everything correct by only reversing polarity of the drums that you're micing the backside of. As far as the impact on the PA, typically the sound of a drum fill is not a significant percentage of the energy radiated in the room compared to the energy radiated by the entire sound system. That said, if reversing the polarity of the kick drum in the drum fill does impact the sound of the PA or if you want the PA and the drum fill to have the same polarity then delaying the main PA back to the drum fill location and reversing the kick drum polarity in the main PA as well will give you that unification. Though delaying the PA to the drum fill can create other issues on stage making the PA sound very late depending on the room setup so be careful with that and be sure to listen to any changes you do and make sure you're not creating more problems than you are fixing
What if you have no drum fill? Do you still flip the polarity on the kick and the bottom snare mic? Is there any harm done to delay the PA to the backline? I always try to line those stage amp voice coils right where that kick beater smacks. If so, I'd probably have to pencil in the latency of the driverack and if I'm using a digital console. I love analog consoles more!
When I perform kick drum polarity determination, and I determine the kick doesn't need to be inverted? I'm going to take a guess that my bottom snare mic will remain positive polarity same as my kick, a all stick side, snare top, toms & overheads will need to be flipped to a negative polarity? Did I pass or fail? 🤞
The direction that a microphone or a speaker faces does not impact the polarity except if it is a figure 8 mic or speaker dispersion. A cardioid mic picks up in polarity sound everywhere except behind it is just a reduced volume. A figure eight mic picks up in polarity sound in front and out of polarity sound behind Super cardioid and hypercardioid mics have lobes behind that are reverse polarity. With everything except for a figure eight pattern mic or speaker it's better to think about it as a pressure way and ignore direction. If an initial positive pressure wave hits the mic, The mic will output an initial positive voltage regardless of the direction a microphone is pointed or the direction the pressure wave comes from
I understand the part of mic'ing the backside vs. front-side of the drum causing different phases, that's obvious and if you mic front of the snare, and back of the kick, you get phase cancellation. But I'm confused by your drawing. Why would one place a speaker in that position regarding the placement of the drums on the stage? I mean you try to minimize all PA-noise from the stage with arrays and use in ear monitoring for everyone for this exact reason, that you do not have miscellaneous sound sources on stage and the performers can save their hearing for the decades to come. Maybe I'm misunderstanding something here?
For many artists and types of music, the drummer (as well as the audience) will have a desire to feel the sound in addition to hear it. That thump a drummer feels adds excitement and is often desirable. Asking why a drummer would want a powerful sensational sound created by his or her drum kit is perhaps not unlike someone asking xwhy doesn't everyone drive really slow?" It's safer." Or why would anyone jump on a snowboard or motorcycle, it's dangerous. But the reality is that a percentage of humans, for better or worse have a desire to feel thrill and adrenaline and impact. Some drummer may say it helps them get lost in the groove and energizes them to have powerful drum fill. There is no right or wrong but some things are more fun than others.
Sir they something wrong here do you remember adding vectors I think what you are doing causes cancellation so reduces feedback place two speakers facing each other put your head in middle when in phase they no base Or draw the vector diagram 😊🌈 I out phase vocal monitor + mic + foh - Monitor all vector add up
No need to over complicate. Kick drum has pretty much a figure 8 output with opposite polarity on the drummer side vs other side. If you mic the beater side, drumfill is on polarity, mic the other side, it is out of polarity, just like snare bottom vs snare top
With the Neuralink, we’ll be able to delay the sound inside your head to get the phase between the IEMs and your bone conduction back to the expected behavior so it sounds like you have no IEMs on.
there's an open course from the MIT (if i recall correctly) about how sound is processed by the brain and unfortunately there's so much more work to be done before we even start deciphering the algorithms of sound decoding, let alone altering the process.. like for example, for the longest time even monitoring the activity of the 'sound regions' was v scarce because of the inaccessible locations, scientists would need to wait for patients to go thru other scans and monitoring meant for other observations than sound related. compared to other stuffs, hearing is low priority :( -and it's understandable to some extent..
Well the body has a natural mechanical electro acoustic resonance that we can hear when we speak. Plug your ears and speak and you can hear it. That's something that is a physical entity mechanical and not having anything to do with perception and unless you start chopping up bodies or altering the actual human structure itself is going to remain somewhat consistent. Then you have the part you hear through your ears the arrival time and frequency response and distortion and characteristics of the signal presented to your brain via your eardrums. Now if we can teach our brains to add time delay to our eardrums, then the internally created an externally heard signals theoretically could be altered in how they interact with each other. But that seems awkward and unlikely. More likely is that the interaction between those two signals exist And if they are summing well or canceling each other out at various frequencies we can either get used to that or not. But whether we get used to it or not has nothing to do with the fact that we have two different signals arriving and being perceived. If one is late in relation to the other which is what happens with acoustic signals it will sound late because it's arriving late. The goal of tricking the brain to think that a signal arriving late is actually not arriving late and that we don't hear or train our brain to ignore the interactions caused by the comb filtering of the two different arrival times seems a tall order at best.
@@DaveRat thanks mr Dave... i found the MIT course link, in episodes 15 and 16 prof Nancy Kanwisher presents some fascinating facts about how the brain analyzes sound related data. the signals are basically split and sent to different 'centers' specialized in different tasks, you may find her knowledge interesting... she discovered two 'brain areas' w/ functions in recognizing fine facial differences between individuals and environments; she has a deep understanding of how the brain interprets the signals it receives from the eyes and ears and has the experience of presenting/teaching such complex topics :) th-cam.com/play/PLUl4u3cNGP60IKRN_pFptIBxeiMc0MCJP.html
Actually this vid is a rerelease of a vid I did in 2010 which was based on an article I wrote for Live Sound International Magazine. Perhaps do a Google search on "Dave Rat polarity" and see if anything shows up
Mics respond to the acceleration of the drum skin. The initial impulse of the kick will be in phase, but the response after that will be 180 degrees out of phase. It's just how mics work. It's OK.
It's OK because the PA speakers do the same thing. In phase on the impulse, 180 degrees out for the tones. It's really a problem with how air and transducers interface.
With which side of the the drum head? Mic'ing one side of the drum head will get the speaker moving in the opposite way as to mic'ing the other side. So... Mic'ing one side, the speaker will be in polarity with the speaker and mixing the other side the speaker will be out of polarity. Turns out that mixing the front of the head, stick or beater side results in the speaker being in polarity with a properly wired system But if you mic the the back of the head the speaker will be out of polarity. We do this all the time with sbate top and bottom mic. Top mis is in polarity with the drum fill and bottom mic is out of polarity with the drum fill Mic'ing the back of the kick head is the same. Simple, testable and repeatable
@@DaveRat I prefer drummers to have IEM. Phase of the kick is correct. Positive pressure in phase with the pa. I should invert phase on snare/tom because mic’ing from top.
That discussion actually came up several times over the years when I mixed Chili Peppers. But the decision was made that samples would be better for bands that are ok with musicians that are ok with the audience hearing sounds that they are not actually creating live. Kind of like photoshoping pictures, it's fine but not for everyone and there is a beauty and integrity to bands that actually are making the sounds that the audience hears
Sorry Dave, but this is still incorrect. The majority of the low end from the kick drum itself that the drummer hears is coming from the hole not the batter head. So the drum wedge needs to be in polarity with the mic not phase reversed. Please test this for yourself. Using incorrect polarity to fix feedback is also at the expense of low end for the drummer which will be counterproductive. Using damping, eq, and wedge positioning will provide more useful results.
I have been doing this for many years when the vid was made in 2010 and for many years after. The vid explains how to test. It's easy to demonstrate and is the same reason snare bottom is polarity reversed
@@DaveRat I have a lot of respect for how extensive your experience is, but if you listen to an acoustic kick drum with a port. You will notice the low end projects from the port not the batter head and due to the low wavelengths wraps around the drum to the drummers head. If both sides were equal in low end projection you'd get a cancellation. The shell focuses the low end. While your method works in theory it doesn't translate to the sub of the kick drum due to the lower wavelengths diffusing around the drum. I have tried your method many times and come to the same conclusion.
@grimslater if you are not already doing so, have your considered becoming a consultant that high end touring engineers can hire to help find mistakes like this? You can already say that Dave Rat was your first client and put this bass drum case study on your website.
I describe a simple test in the video. I recommend that you try that and see if it aligns with your description of what you think is happening. I understand what you are describing. "That a kick drum radiates sound similar to a ported speaker that radiates in-polarity sound in all directions" And that is a valid assumption and partially correct, some frequencies do radiate that way and it will vary with the tunings of the drum. The resonant head of a kick drum does time delay and act kind of like a port on a speaker. And as you probably are familiar, The port of a speaker takes the outer polarity rear sound of the speaker and delays it such that it can sum in-polarity with the front of the speaker and add low frequencies. So in that tuning frequency range the kick should put out an in-polarity -ish signal all the way around. That said, I think you will find that kick drums in general tend to radiate sound more like a figure eight mic or open back guitar cabinet. Wherein the kick drum is loudest when you stand directly in front of it or directly behind it and when you stand off to the sides it is lower in volume. This is easily tested by wandering around a kick drum. The reason it's quieter off to the sides is the same reason and open back guitar cabinet or figure eight mic is quieter off to the sides and that has to do with a substantial amount of frequencies being radiated out-of-polarity on one side and in-polarity on the other side. If there was no polarity reversal then the sound as you walked around the kick drum would either remain consistent or slowly die out to quieter on one side and louder on the other. It is the polarity reversal that causes the null wherein you hear lower volumes off to the sides. So if we can establish that the kick drum puts out somewhat of a figure eight pattern and therefore has an in polarity and out of polarity radiation pattern, we then end up with a scenario where the sound radiated in front is out of polarity with the sound radiated to the back. This is further magnified by any mic used inside of the kick drum which will pick up definitively a difference in polarity even more pronounced. If you want to definitively prove this to yourself another way, mic the beater side of a kick drum and then mic the non-beater side and combine those two signals both in and out of polarity. If what you say is correct they should combine best with the most low frequency when they are both in polarity. If you need the polarity reverse one of the mics for them to sum, just like you would with a snare top and snare bottom, then what I describe in the video is the correct description. As with most all of my videos, I don't ask you to believe but rather I offer you a concept and also the tools to test and understand. Let me know if you get a chance to do those tests and what you come up with or if anyone else does. I would love to hear the outcomes!
@clownhands I recommend you personally test out and determine what is correct whether it's me or anyone else before taking any knowledge as being fact. There's lots of incorrect info out there and establishing credibility of the person offering the info and the info itself is wise The viewpoint of @grimslater is not incorrect, but rather, The assumption that The kick drum is either in or out of polarity and doesn't have a more complex waveform is an oversight
Interesting, except for the fact that no sound tech would ever put the mains behind the drums. In-fact we mount the speakers perpendicular with the kit.
The drumfill can be a wedge or 2 wedges and a sub or whatever. The angle of the speaker makes no difference as the physical angle does not alter the polarity. In fact, with sealed, ported and horn loaded cans, the polarity of the sound is the same in front and behind the enclosure. It is only with open back cabinets where the rear of the speaker is exposed that the polarity changes around back
Also, polarity has to do with the two wires that drive the bin. If you want to discuss the air from the speaker than that is not positive and negative and not even considered as polarity. It would be described as pressure and vacuum. And you ideas of flipping polarity on your mikes has nothing to do with the speakers nor will it make any change in the sound. And when you talk mid and high frequencies the wavelengths are very very short and may be hundreds of cycles between your speaker and your drums. Dave I only get annoyed when I see people who have no clue of what they are talking about trying to convince people their theory is correct when it is NOT.@@DaveRat
Dave, next time you set up a PA. If you have ever set one up? Take a live mike and hold it up in front of your main. Now when you hear that loud squeal,, I can assure you flipping the polarity will do NOTHING. And as far as angle. All Mains are placed at least 10 feet forward of the most front stage mike. So, the stage gets no sound at all from the mains. We must add other speaker arrays on stage to feed the first 20 rows of seats with sound as those people can not hear the mains.@@DaveRat
To calculate rhe wavelength of frequencies, the equation is to divide the speed of sound by the frequency involved. Sound travels at approximately 1120 ft per second depending on air temperature. All those many little cycles before they reach your ears for high and mid frequencies, are easy to calculate In fact we can even do it in our head 1120hz has a wavelength of approximately 1 ft 112 Hz has a wavelength of approximately 10 ft. The interactions between wavelengths in the upper frequencies are very audible and easily demonstratable. The polarity radiated by the front of a speaker is the opposite of the polarity radiated by the rear of that same speaker. Sticking a mic in a speaker to understand feedback it's kind of like crashing into a wall to learn how to drive. I do recommend as I describe in the video, turn the kick up in the drum fill until it is on the verge of feedback, where it is overly resonant but not taking off. Then hit the polarity switch. The polarity will typically either increase or decrease the resonance. Also sit at the drums and hit the kick drum and have someone switch the polarity one way or the other. If the drum monitor is set to a volume level somewhat similar to the kick drum natural level, you will hear summations are cancellations depending on whether the monitor is the correct polarity
I don't look at it as a problem but rather, a comprehension. This is one aspect of the bigger picture of understanding that whenever there are multiple versions of the same sound sound audible from any position, that those sounds will interact in such a way that polarity may be relevant. It could be main PA vs monitors, guitar vs guitar wedge or your own vs vs the in-ears or headphones you are wearing. Those that fully understand and comprehend the interactions are better equipped to achieve superior results and succeed in the industry.
.....yawn.....So it's obvious that Dave myself And everybody else who has done this for 30 plus years is super bored with this business..... If you have any sense go get a real job😊
So, 2 questions. 1) Distance. Your arrival time at the mic is not going to be instantaneous right? And 2) if your fill is 90 degrees off to one side, (as I've seen more times than not on bigger stages) do you get a 90 degree phase shift in the mic (plus whatever time delay you have)?
As far as arrival time the kick drum is two or three feet from the drummer's gut so having the drum fill two or three feet from the drummer's gut gives you perfect timing. And you can be a foot or two off or have a few milliseconds of latency in a digital console and it won't matter much.
If the arrival times are off by 2 ft then to calculate that divide the speed of sound by two and you get 560 Hertz. Where the sound will be one full wavelength off and it'll be a half a wavelength off at 280 Hertz. Since polarity issues are more audible with low frequencies a couple feet is no big deal.
As far as 90° off-axis monitors that's a flawed assumption. The direction that a speaker or drum head is moving is a bit misleading. I use that or reference that to make a point and help people understand but what is actually happening is the monitor is either creating an initial negative pressure wave or a positive pressure wave.
The kick drum is creating an initial negative pressure wave on the drummer side of it and an initial positive pressure wave on the audience side because it has somewhat of a figure eight polar pattern like a figure eight mic.
Stage monitors have more of an Omni or cardioid polar pattern wherein the sound radiated in all directions is the same polarity whether you're in front of it behind it or alongside it.
So it doesn't matter which way the monitor is pointing it could be pointing away from the drummer it's still putting out a positive pressure wave in the low frequencies in all directions.
The kick drum and other drums are different and more like an open back guitar cabinet or an open back speaker where it outputs opposing polarities in front and behind the drum heads
@@DaveRat thanks for the awesome reply!
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Deep k-now ledge !
@aronvanalstine 🤙👍🎙️
Huh. I don’t think IEM polarity has ever crossed my mind before. Thanks!
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The amount of knowledge you have provided me in just a handful of videos is mind boggling. Thank you so very much.
Awesome and thank you!!
I've been looking at phase problems on the FOH side for some time now, why I never asked myself these phase issue on stage ? It's crazy !
Now, you've screwed up my mind forever ! I'll never be able to ignore this step again. I can't wait for my next show...😁
Thanks for your explanation, you are a goldmine !
Super cool and let me know how it goes. Also make sure your monitors and mains are in polarity with each other.
Dave Rat is where it's at.
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One thing a lot of guys also forget is the polarity AND DELAY usage when using Kick IN and Kick OUT. Very important to use a small amount of input delay on the Kick In to maximize the Kick sound to make sure it is in time with the Kick Out.
Yes though it's somewhat depends on the sound you want. If you delay the out mic to the in mic, you will be time aligning for the beater head. If you slightly delay the inner mic to the outer mic, then you will be time aligning the focus onto the resonant head.
So you're kind of selecting between punchy and fluffy
@@DaveRathey man awesome videos and explanations. My only question right now is how do you delay the out kick to the in kick? The out kick is inherently receiving the sound later, so how can you delay it to the in kick? Are you just delaying the out kick slightly to move the positive/negatives further apart to avoid cancellation?
i truly want to thanks you Dave for your every single video
Awesome and thank you Gabii!!!
I always reverse polarity on snare bottom, but it never came across me to do the same on kick drums. This is awesome! Thanks!
Right! it seems so obvious now!
Well said! Diagrams are so helpful! Took awhile to learn this concept with kick/bass in real world- this was so concise and will save others lots of time.
Thanks for sharing the wisdom!
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You’ve been of great help Everytime Dave. Really appreciate you
Wonderful and thank you
Thanks for this Dave! Band I'm touring with are all on IEMs with no wedges but what you said about the vocals on IEMs was really interesting and will definitely try it out
Cool, lmk how it goes!
Loved the bit about in ears. Will have to try in the studio!
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The small detail to never trust that mics and speakers are always wired correctly is gold advice. I'll admit that sometimes I assume things are built correctly and set polarity based on that detail. Thank you for the advice!
Yes, I have actually found mics made by manufacturers incorrectly. The entire Electovoice NDYM308 and 408 line was initially released out of polarity. Then fixed after an awkward call from me to their tech support.
Also all the in-ears made by JH Audio are made out of polarity as well as old JBL speakers for decades till they finally switched.
Totally agree. I found out, a while back, that two of the 10 wedges at the venue that I work at were reverse wired!
@raycathode498 🤙🔧🤙
Amazing! I can't wait to test all this out at the next show.
Let me know how it goes
Hey Dave I was a member since the beginning but TH-cam deleted my channel so now I have to start from scratch.
In the past we've had discussions about impedance and a few other things.
Feels good to be back, supporting you, and getting the inside scoop on whqt you're up to! Also I just used my new xlr sniffer for the first time this weekend at two gigs.
Every cable I grabbed went into your cable tester first before being deployed. 😎
Hey hey Zack and welcome back!!
Amazing. I always have epiphany moments watching these, even if it seems like a topic that I think I understand fully.
Awesome and thank you
This is gold. Thanks for posting this. Would have fixed a few strange things I had come across.
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Thanks for the masterclass! Amazing stuff
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Well, I’m off to rewire the positive/negative pins on all the kick mics….But in all seriousness I’m excited to try this for real at the next rehearsal. Not sure if the space is large enough to discern any difference, though, with all the sound bouncing and clashing everywhere. But next sound check at a show, it’s getting tried as well. Great stuff, brother.
LMK how it goes!
Don’t do that build a short cable to reverse the phase and experiment if you add switch it’s much easier
@@DaveRatWell, sound check went great. Our drum fill is a built off two sends. One is kick and bass into a sub, the other is all vox and occasionally on bigger stages a guitar cab that’s far away. Polarity reversed the kick signal to the drummers sub. Was able to cut the level pretty significantly, down to something that seemed much more reasonable and in line with what the other stuff was sitting at. And I may just be imagining it, but it felt a lot more “tame” to work with (best description I’ve got). I guess because I wasn’t right up against clipping and diming the fader out constantly. But either way, big help so far. Thanks again, brother! That’s exactly why you’re my go to source of info.
@damianthielemier6249 very cool and exactly my experience as well.
Less gain needed and more constant sound.
Dave, last year I did a series of shows with a band and tried something different from past years that is similar to this topic. I had all the mics correctly wired for Pin 2 positive. The stage monitor amp has a switch that reverses the polarity on its inputs, so I engaged that button. This resulted in Pin 3 being positive for the monitors. Having this setup, I was able to gain more volume and practically no feedback during the show. You could still get feedback if you turned it up WAY loud, but I found no reason to set it that way. Mind you, this was just an experiment and it worked out great for me.
Very cool. The thing to watch out for by switching the polarity of the amp rather than specific channels is that it will make some things polarity correct but make other things incorrect
Basically, a setup of about 10 mics (all SM58's, except for 1 AKG C1000S). The band is dixieland jazz. The drums were not mic'ed, as they carried loud enough in the venue to warrant that configuration. Everything into a MixWizard 16:2 and then patched into the venue p.a. system.
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Excellent video, Dave! Thank you for sharing your knowledge! You are a treasure to the music, audio & human world!
Thank you thank you!
As an electronics engineer, I am slightly embarrassed that I didn't think of this ... Thanks for the wake up call 🧐🙂👍
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Few drummers are still using giant wedges as monitors, and the few that do usually have them coming at them from the sides rather than from behind. The majority these days are using IE monitors.
What's important to know is that it makes no difference whether the drum fill is on the side or behind or even next to the kick, the pressure wave is the same.
If the drum head is moving away from the drummer you want the speaker moving away from the drummer behind in front on top makes no difference.
Also, I don't doubt that many of the drummers you work with are relying on any ears and do not use drum subs. But it's important to know that is not the case with many of the larger bands and artists and many musicians.
And just because some drummers don't use drum fills, that is not a good reason to bypass understanding this important concept and it is important to know that this concept also applies to drummers using in ears!
Having the in-ears in polarity with the acoustic output of the drum from the drummer's perspective and position will give you improved results and happier drummers.
As the summation of the acoustic sound and the in-ears will be complementary rather than destructive.
I
This is one of the most useful videos I think I've ever watched. I just run a bar PA, 2 subs, 2 tops, 3 monitors and 1 center fill when needed. Makes a ton of sense to flip the kick drum, I guess with my bass amp, since I don't run it in my wedge, I would just be competing with the subs? I don't mic it, I run through a IR loaded DI box, so I guess I would want the amp to be the same polarity as my subs since they radiate outward kind of omni directional?
Yes, typically.
This checks out with what I’ve always found! I wargame polarities for drum kits in IEMs while actually hitting the drums myself sitting there behind the kit and setting them so they sound best for the drummer.
Also agree on vocal mic polarity! I discovered a long time ago that various IEM, mic AND even peoples hearing seem to have different polarity. I always ask a singer to listen to both ways and am sometimes surprised by the preference. I have done this even with the highest level artists. I get some people who say they ‘don’t understand audio’ and ‘just want me to pick’. They can instantly tell what sounds better to them when they take a second to listen.
With regards to vocal mic latency, with digital systems we are approaching critical mass IMHO. In my rig i have Sennheiser D6000 mics (2ms), Avid S6L (2ms with no plugins), and Wisycom IEMs (1.1ms on Analog input and their hidden Lower Latency mode). In my testing latency was worse on Wisycom going to the AES input - presumable because the non defeatable SRC is slower than AD/DA conversion.
I take it you mix monitors. As a FOH engineer, I want the artist to hear exactly how they present to the mic, with no EQ, no compression, etc. They then adjust mic technique, tone of voice, etc which gives us the best product. Most monitor engineers I know want to work counter to this and give them a better than reality sound. I feel like every performer should have themselves, whether it be instrument or vocal exactly how they are presenting it so they can adjust their performance. Of course everyone else in their mix should be as dialed in as possible. Tune the vocals for the rest if you can so the singer can adjust to in tune harmonies, for example. Compress the others so they can hear how wildly they are with mic technique in comparison. This way everyone gives a better performance and we don’t have to rely so much on the outboard. It always sounds better when they just do it right naturally whether its being in tune, compression, or EQ. What do you think?
@@tigeraudio I've been a touring monitor engineer exclusively since 2002. I give my clients whatever they ask for if they ask for it. If an artist wants a specific sound in their monitors, it is my job to provide it, not inflict my personal taste on that person. And you'll definitely never hear me say "The FOH guy told me I can't EQ your vocal and you should sing better."
I have had a string of very long contracts over the years (12 years with my current artist) thanks to that willingness to serve the desires of my clients. If asked my preference, I prefer that the musician provide to me the sound they would like reproduced so I can deliver it back to them unaffected. We spend a lot of time tuning drums, selecting vocal mics, and tweaking amp modelers and keyboard presets to achieve that. However, I am not so hard headed that I will not use equalization if it better serves the sound of the source. I rarely look at the picture of an equalizer while adjusting it, rather I turn knobs until it sounds right. If the picture looks like a mountain range to get the right sound, I simply do not care.
Are you insinuating that adjusting to polarity of microphones for the best sound quality in the monitors is providing better sound quality than reality and a detriment to the performance???
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@@cgtbrad I am not implying anything regarding anything. Strictly academic conversation. Obviously you give them whatever they ask for. I didn’t say anything about polarity. I was asking for your observations. I see a lot of compression and even tuning used on ears and what you get for a source is getting worse and worse. I think when we had less technology available to us, we had better performances. In the studio, we never did anything to their voices and they would hear themselves exactly how they sounded. I think that was the point of IEMs. I was only there for about 2 years before the recording “business" started to fold as people started to be able to buy their own gear for the cost of a record. Les Paul and Mary Ford used to watch the meters on the tape machine while singing before compressors existed.
@@tigeraudio I’m not aware of any practical way to tune vocals for artists in their IEMs. As far as I know the Waves and Antares plug-ins have too much latency for that and I think it would be really weird to sing while chasing auto-tune in their monitors.
I compress very lightly with a limiter only for yelling between songs, and use dynamic EQ to taste and for de-essing.
I spend a lot of time on this. As would any live recordist, I have the luxury of printing checks and rehearsals, conducting tests prior to show. My discovery lets me establish a relationship between the multiple mics and multiple sources in those mics, and I find it always helpful to my live mix.
I prefer + pressure on BD and snare, that there is a tonal difference, so I use that as my starting point and treat other parts of the kit mics as groups. I usually find real progress aligning OHs to snare and very small delay in both OHs can help. In post, I often nudge the OHs backwards and the benefit to snare sound can be very real. Once I solve that relationship, hats and toms are usually left as-is.
I know the circumstances are quite different for my purposes than they are for you in live sound, but the principles are the same and I’m really happy to see your discussion of them here, Dave.
Very cool and paying attention to the details can make the difference between good and great. You have the luxury in recording to choose whether or not the kick drum is a positive or negative pressure. Though if your speakers are linear it shouldn't matter and theoretically if you hear a difference between an initial positive pressure and negative pressure it should be just nonlinearities in your listening devices.
Beyond that, with a drum fill and the actual drum and combining those two signals, The kick drum creates an initial acoustic negative pressure wave from the drummers perspective that can't be altered with a switch. So whether we want a positive or negative pressure wave doesn't matter what matters is matching the drum fill to the acoustic pressure wave of the kick drum for the drummer sitting equidistant between the kick drum and the drum fill.
And super cool that you line all that up! I have gone deeply down that rabbit hole and achieved desirable results that are repeatable by aligning every mic on stage
@@DaveRat Actually, the pressure polarity does matter on a bass drum on every speaker, earphone, etc I’ve ever tried. BD is a special case, particularly as we use it in popular music, in having the fastest and deepest decay of far less than even one single primary frequency wave. If you’ll indulge my assumption, I believe that’s the reason I’ve never NOT been able to hear the difference. Interestingly, that difference is less apparent soloed than in a mix.
And yes, I agree with all you’ve explained regarding the drummer and your speakers.
@@DaveRat Key to my observations about the BD specifically is apparent looking at the waveform, which I do a lot. (Perhaps to my detriment?). The point remains that the + pressure is clearly an order of magnitude louder than even the - pressure half of the first complete waveform at the fundamental frequency. I take this, right or wrong, to mean it has two distinct sounds and I believe that is what I’m hearing when I choose the pressure at my monitors.
@@DaveRat Yes to the every mic! and quite impressive to pull that off in a live situation.
@artysanmobile Yes that makes sense, absolute polarity which would be most apparent if the drum is soloed, should not make a difference unless there's non-linearities in the transducer recreating the sound. Theoretically nonlinearities in our eardrum and hearing could come into play as well but whether the initial pulse is negative or positive is either irrelevant or borderline irrelevant.
The way that the kick drum mic picks up the kick drum and the other instruments versus the mics picking up the other instruments and their polarity and the summation of all those signals bleeding into each other, is highly probable to be audible and impact the sound audibly
You are a gem Dave!
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Thank you for sharing Dave. Very helpful
Awesome and thank you!!!
Very interesting video. But here is food for thought we as front of house operators always like when Kid drum is coupled and tightly locked with bass guitar when the drummer hits the kick, and we the nonstick side of the kick the mic creates a positive rise in the AC voltage, when the bass player hits the string, he creates a positive rise in the voltage. So by switching the polarity won’t induce an uncoupling effect between the kick and the bass guitar.?
Polarity between signals that are not correlated or somehow related to the same source generating them are not impacted by polarity.
Polarity matters when a signal is combined with another version of the same signal.
If the bass player plucks the string upward or downward, the polarity should be reversed, right? Or pulls on a string vs hits it with their thumb, those are opposite motions. Which one is correct with the kick?
The reason polarity matters for the drum fullia the 2 versions of the kick sound. The natural sound of the kick and the reproduced sound of the kick
For the bass player, whatatters is the sound of the bass rig and the sound of the bass in the mons combining in polarity.
Polarity is a relative concept. There is nothing to relate when the signals are unrelated, even if they are playing the same song and in time, they are not polarity relat d when coming from differing instruments.
I can see how inverse polarity in FOH works better for on stage as the kick drum moving out would make the FOH subs move in reverse thus keeping the positive pressure onstage and not cancelling out the kick for the musicians. But how does this affect the audience in small to medium venues? Because normally the audience could hear the initial positive pressure from the kick but with it phase reversed in the FOH you now have a reverse polarity kick in the subs couple with a positive waveform from the kick drum itself. 🤔
So is it more important for the kick to be in phase for the musicians on stage or the audience who is there to hear the band?🤔
I heard once that everything we do in professional audio is based on a compromise since everything in audio is theory and there are no laws of audio.
Love your videos brother! It's all about helping each other learn how to provide a better experience for our audiences. Because bad audio at a concert just makes everyone sad. 🤘
When two sounds sources are heard at approximately equal volume and approximately equal distance polarity matters a lot.
So from the drummer's perspective where the kick drum is loud for the drummer and the drum fill is also loud having the drum fill in polarity with the kick drum is important for the drummer.
From the singers perspective who is on the opposite side of the kick drum and getting a different polarity from the kick drum The kick drum and drum fill will tend to cancel out if they're the correct polarity for the drummer.
But if the rest of the monitor is the same polarity as the drum fill all of the monitors will be in polarity with each other and the acoustic kick sound will be out of polarity with the rest of the monitor rig for everybody but the drummer this is a concession that's okay.
The monitor rig should be the same polarity as the main PA. So if the kick drum is polarity reversed in the monitor rig to make it correct for the drummer then the kick drum should also be polarity reversed in the main PA.
This means that the main PA and monitor rig will be the same polarity as each other and anyone standing on the edge of stage halfway between the monitor rig and the main PA will get a summation rather than cancellation.
The main PA and subs will be less likely to suck all the power out of the monitor rig which is what happens if the any instruments or the entire monitor rig is out of polarity with the main PA
So the driving factor in this is the one person that is equidistant from the acoustic kick and the drum fill which is the drummer and wants to kick them polarity is established everything else just follows
@@DaveRat Again with an amazing explanation! That makes allot of sense! Thank you for all of your insight; it is truly helping those of the younger generation following behind you. 🤘
very cool info Dave, thank you!...and a happy Easter to you and your family.
Happy Easter and thank you!!
Similar principle as snare bottom, except you are also making the snare bottom in phase with snare top when you flip snare bottom too.
Correct and the key ck mic is the back of drum, so it should flip just like snare bottom
Great explanation but I think nowadays one must consider processing delays, too, because way too often the whole loop isn't fully analog and a single AD-DA conversion may cause enough latency to cause destructive interference thanks to latency even if your polarity is correct in theory. If you have unknown latency in the system, the best you can do is to have constant volume source (might be a bit hard for human controlled hits but doable with a good drummer) and try both ways for polarity and choose whatever results in higher reading in dB-meter from the position where you want to hear the monitor.
Latency of 1 to 4 milliseconds is just like moving the drum fill 1 to 4 ft farther away. Having a couple milliseconds latency and putting the drum fill a little closer to the drummer solves it easily.
Polarity remains The dominant issue for latencies under four milliseconds.
Above that polarity still matters but it has less of a positive impact when you get it right
@@DaveRat 4 millisecond latency causes full destructive interference for 125 Hz frequency for the position half-way between two audio sources, 1 ms latency causes full destructive interference for 500 Hz frequency at the same position even when the audio is played in correct phase. This is no different from room modes or boundary interference.
Yeah that's true, and getting the drum fill perfectly distance and time aligned to the drummer's gut from the drum head is optimal.
And also the summations are pretty messy and the resonant head of the kick drum tends to be late and add the equivalent of some latency itself. What I found is that with drum fill fairly close to the drummer, polarity has a more audible impact than altering the latency two or three milliseconds
Would love to any result from testing or messing around with it if you get the chance to do so
Microphones are wired backwards compared to a speaker. So if you ever use the speaker as a microphone you have to flip the polarity. Or turn the speaker around and use the magnet as the face.
Correct!
Now I can make a subkick out of a 10' or 8' speaker, just flip the polarity, right?
@@zmarasigan9788 yes. but be careful with the signal level. It’s a big 10 inch diaphragm with a big coil and a big magnet. I would test it on something cheap first or use a meter to measure the output. some people wire a - 20 db pad into the circuit.
It's not that straight forward. Mics are wired backwards polarity to creat a correct signal.
If you wire a speaker correct polarity and use it as a mic, the output polarity will be reversed.
Positive voltage on positive terminal moves speaker outward.
Positive pressure on speaker moves speaker inward and creates negative voltage on positive terminal
I am more of a studio buy but I always flip my overheads out of phase to see if my kick drum sounds better. I am sure this applies to live.
I personally prefer undergrads for better sight lines and improved time/distance alignments to the toms and Tom mics
Awesome Dave. Curiously, wouldn't vocal mic cause negative pressure at the mic yet positiv into a wedge?
A positive pressure wave pushes the mic diaphragm inward. On a properly wired mic, the mic dia moving inward created a positive voltage on pin2 of the XLR. On a properly wired system, a positive voltage on pin 2 moves the speakers outward.
Positive pressure from the mouth, positive pressure from the speaker.
With a properly wired system, wedges are in polarity with the singer voice and in polarity with all signals presented.
The issue with the kick is the mic is mic'ing the out of polarity side of the kick
Whatta Wonderful Blast From The Past! 😆👍
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This is one of the videos ive been waiting for a long time !!!
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Outstanding info, thank you as always!
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With a mic in the kick, im leaning towards using the front head as my Starting point for polarity reference, whith the idea that the driven head will contribute to the sound more than the resonate head or shell, and possibly more than the reso head and shell combined. Also, and not that it makes a difference for frequencys lower than a 1/4 wavelength than the longest side of the mic but directionally will come into play a little bit with the mic, I presume. I'm here to learn like most of y'all, so let me know if im making any incorrect assumptions.
Does this polarity concept apply to vocal mics also?
I recently found myself in a space constrained situation where in order to make everyone fit, the vocal mics were placed slightly in front of the mains. Feedback was obviously a huge issue.
Had I had a polarity switch and put the mic signal out of phase with the main mix, would feedback likelihood have been reduced?
Polarity on vocal mic vs in ears matters and I did a few vids on that. As far as mains or mons vs vocal mic, yes it matters for the singer but won't alter feedback much. It will alter the way the singer hears the sound.
Love the presentation 🔥
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Perfect!!! Learned something new for sure.
Awesome as usual
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So with vocal and guitar mics the air pressure goes in to the mic capsule. Does this mean they are usually mixed off phase of the drums, or are those usually swapped as well? I'm guessing there is no "standard" for DIs?
Polarity is a relative term. A sound source itself like kick or voice or guitar is neither in or out of polarity by itself.
But, when comparing two versions of the same sound like the front or back of a drum, the sound of a voice and that same voice being mic'ed and amplified and coming out of a speaker, you now have many factors involved when combining or adding those two versions.
Things like time offsets, eq differentials, phase shifts and polarity will have impacts on how well or poorly they can be recombined.
Polarity is probably has the most dramatic impact. Because if polarity is reversed on one of the two versions of the same signal being recombined, then total and complete cancellation can occur.
So a guitar speaker or a voice or any sound source has a sound radiating out of it and if you put a mic on it and that sound comes out of a monitor speaker then that is another version of that sound source.
With a properly wired microphone and system the natural sound or original sound will be in-polarity with the sound coming out of the monitor speaker. If for some reason The amplifier where the monitor speaker or the microphone has a polarity of reverse, then the two versions of the signal will be very destructive with each other when listening to both at the same time assuming that the other factors like time offset phase and EQ differentials are not significant.
Dave, would the polarity of similar sources make a difference for front of house if you’re not using a separate monitor console? Would having the kick and bass guitar out of phase cause undesired cancellation?
If you're from the house system is in polarity with your monitor system which it should be, then any polarity versus that you do in the monitor rig should also be done in front of house. Otherwise you will get cancellations between monitors in front of house that may be audible in places that are equidistant from the monitors in front of the house
Reversing polarity is a great idea, isn’t there is one more way to achieve similar results on digital consoles by inserting input delay to the input channels it will give the same results in fact more accurate in some cases than switching polarity?
Great video thanks for sharing this with the world 🙏🏽❤️
Hmmm. Not exactly. Adding delay can align the kick with other drums, but just like delay can't fix your left studio monitor if it's wired out of polarity with your right monitor, delay won't fix kick out of polarity with drumfill from the drummers perspective
@@DaveRat Sorry my bad you are absolutely correct.. 👍🏽👍🏽
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Dave you say you use the same polarity on the kit for monitors and front of house? With kick for example would flipping polarity not make the low end more out of phase with the main PA?
If your pa, your subs and monitors are ported boxes or horn loaded or sealed, they will put out the same polarity pressure wave in front and behind the enclosures.
If you rec polarity on the kick so the drum fill creates an initial negative pressure wave to align with the acoustic negative pressure wave created by the beater hitting the kick head, then the kick sent to side fills and wedges would also create an initial negative pressure wave.
So you would also want your main PA to create an initial negative pressure wave such that the money rig and the main PA are the same polarity.
Any listener that is equidistant from the mons and mains or mons and subs or sid3fils and mains, would then hear summation of the mains/subs and mons/side fills.
Flipping polarity in the mains or mons and not doing the same everywhere will cause cancellation between mains and mons and that is usually undesirable as the mains will tend to suck the LF power out of the monitor rig
@@DaveRat thanks for the detailed reply! I guess my thought was that from the perspective of the audience, that initial pressure wave would be positive, or opposite to what the drummer experiences, but sounds like the overall effect of mons being coherent with pa is more important. Anyway, next time I get a chance I'm going to try this out!
Ps. Just found your channel, love the down to earth yet enthusiastic vibe. It reminds me that it can be fun to learn and experiment with your work 😎
Cool cool and thank you. Yeah, can be confusing as it's not really the direction of motion but rather it is whether the pressure wave is positive or negative.
For a speaker in a cabinet the pressure wave is the same in front and behind. For a kick from, open back speaker cabinet or any other sound source with a figure 8 radiation pattern, the pressure wave behind is the opposite to the pressure wave in front
Definitely going to give this some more thought next chance I get! Thanks again 🙏
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Do you consider polarity reverse ambiance mics for iem ?
Having ambience mics of the musicians can hear the audience is desirable by many bands. As far as polarity reverse, that could reduce some low-end content and it's worth giving a listen to and see whether in polarity or out of polarity is preferred or sounds better.
Great tips thankyou bro
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ooooo... I wonder if placement relative to the edge of the cymbal matters drastically when micing cymbals.. the standard vibrational modes are way more complex than the fundamental modes of a drumhead- so the peaks and troughs are going to dispersed more 'randomly' across the cymbal. Have you found even anecdotally flipping polarity when micing bottom of cymbals really does gives better results??
No, cymbal polarity does not audible matter but mic polarity on the cybal can matter. Because low freqs from drums bleed into cymbal mics. If the mics are out of polarity, the drum bleed can cancel with other mics.this may be a good thing
Thank you, Dave! Your advice is very helpful. It makes perfect sense for monitoring. I have a question which leads to other questions. Does it matter for subwoofers (or other types of speaker in general) if the drivers move out first or in for better impact? How it differs with different types of subs or configurations? If that matters maybe it's better to use straight polarity of Kick In mic in FOH in most situations?
Polarity only matter when 2 versions of a signal interact. Like the drum version and the drum monitor version
Or one sub vs another sub.
@@DaveRat yes, it's a good way to think about it. Perhaps I'm too specific here and need to clarify. We know that speakers are not ideal. Considering actual speaker cabinet in a space with real amplifier as a system that has it's limitations, does it performance differ on powerful transient material such as drums if it push air first or pull? I've played with polarity on single kick drum source and noted that my studio monitor reacted differently when I flipped signal's polarity. On headphones I can hear a difference too. It's subtle! Interesting to note that my preference on how kick sounds with different polarity on monitor vs headphones was opposite. In smaller venues where drums plays significant role acoustically it's more about sum of instrument with PA. Maybe on bigger setups where you not so dependant on that, it's not a bad idea to try and find in which way system reacts better? What's your experience in that regard?
You're talking about absolute polarity. And I don't believe anybody's definitively shown that it matters one way or the other. Psychologically we like to believe that something should push us before pulling but as far as physics is concerned it makes no difference whatsoever.
Yes there are differences in speakers and nonlinearities between pushing and pulling. Whether those nonlinearities happen first or second may make a difference for specific speakers but that does not mean that we can hear the difference between a positive going or negative going initial waveform. It just means that we can hear nonlinearities in that specific speaker
It's also quite probable that nonlinearities in our hearing itself may make positive going pulses sound slightly different than negative going pulses.
So it may be possible to hear slight differentials between the two but as far as establishing whether we hear the nonlinearities first or second, I would be remiss to say one is better than the other.
One can easily hear polarity differentials between two sources playing at the same time and one would be quite challenged I believe to determine whether a speaker's absolutely polarity is positive or negative when no other reference points are offered
@@DaveRat very much appreciate that you take time to elaborate on that topic! Some nice food for thought.
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Great. Thanks for this
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How about the bottom of the snare mic, which picks up the kick, that's in front of the kick and behind the snare?
I know I should probably try both ways, but what's the science behind it?
I'm asking for clarification because bottom of snare mic I usually do not gate
Set the mic polarity to align with the dominant instrument that it is picking up. If kick in the snare bottom is a concern then put this near bottom might closer to this near bottom to reduce the issue
@@DaveRat thanks
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So drums with internal mics should also use reverse polariy?
Yes
What if you mic the kick from the batter side? Would you still have to deal with polarity issues? I've noticed that doing this has cleared up alot of issues for us but I don't see anyone else doing this.
Yes making the beater side of the head, Will give you the opposite polarity of making the other side.
It's a mystery as to why no one is doing it as a normal and obvious thing.
I mean we see people hitting the polarity reverse on snare bottom when they mic the bottom of the snare. If you make the front and back of a kick drum you would naturally put a polarity verse on the back mic. It just seems quite obvious that when you mic The back side it should be polarity of verse and when you make the front side it should not.
When I first figured this out I tested it over and over again and couldn't believe that something so logical and obvious was not common knowledge. Puzzling and also fun!
hi dave i have a wierd one got no phantom power working on but 2 channels even with the old mixer the same thing could it be the wiring under stage has a glitch ?? making it bypass? i have no polarity switch on a Behringer pmp 6000
If the lines work with non phantom mics but not phantom, that means there is a pun 1 lift or a bad ground
@@DaveRat ok ty im gonna unplug the understage wires in between snake and mics and see
@mikepruett1745 I designed a cool tester for exactly this kind of thing.
They will test using Phantom power or the sender unit and you don't need both ends of the cable in the same spot.
soundtools.com/cable-testers-page-ssxlr.html
wadafuck thanks a bunch! makes total sense. I never thought about this kind of thing in relation of the positioning of speakers in a live situation...
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In a situation like this do you time align the drum fill to match the distance from the kick drum to the drummer? I assume time alignment would be a big deal when dealing with phase alignment.
With analog putting the drumfill the same distance from the drummer chest as the kick is, can help summation. With digital, the drumfill typically can't be close enough as latency makes it farther
As far as how much it matters, it matters most with low frequencies. And being within 1/4 wavelength is good.
A 1/4 wavelength of 80 Hz is 3.5 feet.
So +/- a f w feet from perfect alignment is all good
@@DaveRat right on that makes sense. Great videos man, been learning a lot from your channel
Awesome and thank you!
I see your diagram as if the monitor was behind the drummer. What if the monitor was 90degrees to their right or left side? Would it be the same or make a difference?
Yes it would be the same even if the monitor was pointed away from the drummer. Sealed back speakers and ported speakers will output the same polarity in all directions.
But if you had a drum fill with an open back enclosure, then if the drum fill was pointed away it would be the reverse polarity as pointed towards you and if you were looking at the side of the drum fill you'd be in a cancellation area.
My point is that most speakers with the exception of open back versions, output the same polarity in all directions so it doesn't really matter which way they point they're just louder in front
Definitely helps!
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The for me is, is it the microphone out of polarity or the speaker?
I usually flip the polarity on the drum fill output, not on the kick drum mic.
Also, latency, specifically on digital consoles… a couple of milliseconds have a large effect in all these scenarios
Latency of 2ms just makes the drumfill a virtual 2 feet farther away.
Flip drumfill polarity is fine but now all the drums like snare top and toms mic'ed from the top are out of polarity with the drumfill. So you need to push even more polarity switches.also the drum fill is now out of polarity with the rest of the stage mons, so bass sent to drum fill will be reversed from bass sent to wedges or sides.
@@DaveRat correct, usually it’s only a drum sub in most of the shows I do.
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I need more information on this. Possibly with electronic testing. Because the drum head moving forwards towards the audience should make the speaker move forwards towards the audience. He has it backwards. The microphone facing the front of the kick drum would actually naturally create a negative phase response
Mics are typically wired such that a pressure pushing on the diaphragm creates a positive voltage on pin2. A positive voltage on pin 2 should make a speaker move outward. So mic dia moves in means speaker moves out.
But looking at it from a dir action of motion perspective is not ideal as typically a speaker in an enclosure readiates the same polarity pressure wave in front and behind whether it is pointed towards or away from you.
The issue is that a kick drum has a different radiation pattern than most speakers in enclosures as a kick has more of a figure 8 radiation pattern. Where the polarity on the drummer side is reversed from the polarity on the audience side.
If you want the kick to sum with the drumfill for the drummer, you need to polarity reverse the mic or drumfill.
If you want the drumfill to be polarity correct for the single or audience, you would not polarity reverse it.
Typically though, it is more important to have the drumfill sumwith the kick from the drummer perspective than to sum from the audience perspective.
Looking at it from a
@@DaveRatthanks for the informative response. you rock
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Does this apply to front of house or just drum fills?
Getting the polarity between your monitor rig in front of a house rig is important as well. I did a video a while back on that but I don't remember what it's called.
The concept of reversing polarity of the monitor rig because the wedges are pointed the opposite direction is incorrect.
You will want the polarity of the main PA to be the same polarity as the monitor system
If the kick drum is polarity versus in the monitor rig then you will want to polarity reverse it in the main PA as well
Great stuff!
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Is that Jeff Spicoli? Nice to see he found a trade.
No greater compliment! Spicoli represents the wonderful embraceive happiness fun cool and an in-depth wisdom below the surface. Thank you
@@DaveRat Gnarley dude.
@timr3563 🤙🤙🤙🤙
So if you have the speaker moving in the opposite direction of the kick drum to reduce feedback, wouldn’t that technically be considered out of phase?
No, bothe moving away and then both moving towards is in polarity.
But towards and away are misleading as it implies that pointing in a diff direction will alter polarity.
Think of " creating a positive or negative pressure wave" and are they both doing the same thing or opposite things. Same is in polarity
Can you just reverse the polarity of the monitor rather than inverting the kick polarity and all non-stick side?
Does this have any effect on the PA?
Yes you can just flip the polarity of the monitor and that will fix the kick but then your snare top will be out of polarity and you're near bottom will be in polarity and your toms will be out of polarity if you mic the top and in polarity if you might come from behind so it just flips all the things.
But what you really want to achieve is to make everything correct by only reversing polarity of the drums that you're micing the backside of.
As far as the impact on the PA, typically the sound of a drum fill is not a significant percentage of the energy radiated in the room compared to the energy radiated by the entire sound system.
That said, if reversing the polarity of the kick drum in the drum fill does impact the sound of the PA or if you want the PA and the drum fill to have the same polarity then delaying the main PA back to the drum fill location and reversing the kick drum polarity in the main PA as well will give you that unification.
Though delaying the PA to the drum fill can create other issues on stage making the PA sound very late depending on the room setup so be careful with that and be sure to listen to any changes you do and make sure you're not creating more problems than you are fixing
@DaveRat that's a lot of serous technical info for this old brain 🧠 thank you, Sir Dave Rat 🐀
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What if you have no drum fill? Do you still flip the polarity on the kick and the bottom snare mic?
Is there any harm done to delay the PA to the backline? I always try to line those stage amp voice coils right where that kick beater smacks. If so, I'd probably have to pencil in the latency of the driverack and if I'm using a digital console. I love analog consoles more!
When I perform kick drum polarity determination, and I determine the kick doesn't need to be inverted?
I'm going to take a guess that my bottom snare mic will remain positive polarity same as my kick, a all stick side, snare top, toms & overheads will need to be flipped to a negative polarity? Did I pass or fail? 🤞
Good information
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What about a Shure SM/Beta 91 sitting in bottom of kick drum ? It’s facing vertical ….
The direction that a microphone or a speaker faces does not impact the polarity except if it is a figure 8 mic or speaker dispersion.
A cardioid mic picks up in polarity sound everywhere except behind it is just a reduced volume.
A figure eight mic picks up in polarity sound in front and out of polarity sound behind
Super cardioid and hypercardioid mics have lobes behind that are reverse polarity.
With everything except for a figure eight pattern mic or speaker it's better to think about it as a pressure way and ignore direction.
If an initial positive pressure wave hits the mic, The mic will output an initial positive voltage regardless of the direction a microphone is pointed or the direction the pressure wave comes from
I understand the part of mic'ing the backside vs. front-side of the drum causing different phases, that's obvious and if you mic front of the snare, and back of the kick, you get phase cancellation.
But I'm confused by your drawing. Why would one place a speaker in that position regarding the placement of the drums on the stage?
I mean you try to minimize all PA-noise from the stage with arrays and use in ear monitoring for everyone for this exact reason, that you do not have miscellaneous sound sources on stage and the performers can save their hearing for the decades to come.
Maybe I'm misunderstanding something here?
For many artists and types of music, the drummer (as well as the audience) will have a desire to feel the sound in addition to hear it. That thump a drummer feels adds excitement and is often desirable.
Asking why a drummer would want a powerful sensational sound created by his or her drum kit is perhaps not unlike someone asking xwhy doesn't everyone drive really slow?" It's safer."
Or why would anyone jump on a snowboard or motorcycle, it's dangerous.
But the reality is that a percentage of humans, for better or worse have a desire to feel thrill and adrenaline and impact. Some drummer may say it helps them get lost in the groove and energizes them to have powerful drum fill.
There is no right or wrong but some things are more fun than others.
Sir they something wrong here do you remember adding vectors I think what you are doing causes cancellation so reduces feedback
place two speakers facing each other put your head in middle when in phase they no base
Or draw the vector diagram
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I out phase vocal monitor + mic + foh - Monitor all vector add up
No need to over complicate. Kick drum has pretty much a figure 8 output with opposite polarity on the drummer side vs other side. If you mic the beater side, drumfill is on polarity, mic the other side, it is out of polarity, just like snare bottom vs snare top
@@DaveRat 😊
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With the Neuralink, we’ll be able to delay the sound inside your head to get the phase between the IEMs and your bone conduction back to the expected behavior so it sounds like you have no IEMs on.
Hmmm, perception vs physics. Alter perception to fix physics? Tall order
@@DaveRat
Isn't that what we're doing via house curves, equal loudness curves and listening levels?
there's an open course from the MIT (if i recall correctly) about how sound is processed by the brain and unfortunately there's so much more work to be done before we even start deciphering the algorithms of sound decoding, let alone altering the process..
like for example, for the longest time even monitoring the activity of the 'sound regions' was v scarce because of the inaccessible locations, scientists would need to wait for patients to go thru other scans and monitoring meant for other observations than sound related. compared to other stuffs, hearing is low priority :( -and it's understandable to some extent..
Well the body has a natural mechanical electro acoustic resonance that we can hear when we speak. Plug your ears and speak and you can hear it.
That's something that is a physical entity mechanical and not having anything to do with perception and unless you start chopping up bodies or altering the actual human structure itself is going to remain somewhat consistent.
Then you have the part you hear through your ears the arrival time and frequency response and distortion and characteristics of the signal presented to your brain via your eardrums.
Now if we can teach our brains to add time delay to our eardrums, then the internally created an externally heard signals theoretically could be altered in how they interact with each other.
But that seems awkward and unlikely.
More likely is that the interaction between those two signals exist And if they are summing well or canceling each other out at various frequencies we can either get used to that or not.
But whether we get used to it or not has nothing to do with the fact that we have two different signals arriving and being perceived.
If one is late in relation to the other which is what happens with acoustic signals it will sound late because it's arriving late.
The goal of tricking the brain to think that a signal arriving late is actually not arriving late and that we don't hear or train our brain to ignore the interactions caused by the comb filtering of the two different arrival times seems a tall order at best.
@@DaveRat thanks mr Dave...
i found the MIT course link, in episodes 15 and 16 prof Nancy Kanwisher presents some fascinating facts about how the brain analyzes sound related data.
the signals are basically split and sent to different 'centers' specialized in different tasks, you may find her knowledge interesting...
she discovered two 'brain areas' w/ functions in recognizing fine facial differences between individuals and environments; she has a deep understanding of how the brain interprets the signals it receives from the eyes and ears and has the experience of presenting/teaching such complex topics :)
th-cam.com/play/PLUl4u3cNGP60IKRN_pFptIBxeiMc0MCJP.html
Just add a happy little tree. Works every time.
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Oh Dave, you had me scratching my head for a second and second guessing all I've learned. Good thing I glanced at the calendar LMAO ! 🤣
Actually this vid is a rerelease of a vid I did in 2010 which was based on an article I wrote for Live Sound International Magazine.
Perhaps do a Google search on "Dave Rat polarity" and see if anything shows up
Mics respond to the acceleration of the drum skin. The initial impulse of the kick will be in phase, but the response after that will be 180 degrees out of phase. It's just how mics work. It's OK.
It's OK because the PA speakers do the same thing. In phase on the impulse, 180 degrees out for the tones. It's really a problem with how air and transducers interface.
But now I'm thinking you're right, either the kick or the snare/tom mics need to be inverted.
With which side of the the drum head?
Mic'ing one side of the drum head will get the speaker moving in the opposite way as to mic'ing the other side.
So...
Mic'ing one side, the speaker will be in polarity with the speaker and mixing the other side the speaker will be out of polarity.
Turns out that mixing the front of the head, stick or beater side results in the speaker being in polarity with a properly wired system
But if you mic the the back of the head the speaker will be out of polarity.
We do this all the time with sbate top and bottom mic. Top mis is in polarity with the drum fill and bottom mic is out of polarity with the drum fill
Mic'ing the back of the kick head is the same. Simple, testable and repeatable
Correct
@@DaveRat I prefer drummers to have IEM. Phase of the kick is correct. Positive pressure in phase with the pa. I should invert phase on snare/tom because mic’ing from top.
Nice one again, Dave! Thanks! By the way... saw you on netflix... Nice! Hahahaha!
Ha! Fun and thank you!!
Cool cool!!🤙
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that was great thanks :)
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Danke!
Wow and thank you!!!!
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Skip the hassle, trigger the kick
That discussion actually came up several times over the years when I mixed Chili Peppers.
But the decision was made that samples would be better for bands that are ok with musicians that are ok with the audience hearing sounds that they are not actually creating live.
Kind of like photoshoping pictures, it's fine but not for everyone and there is a beauty and integrity to bands that actually are making the sounds that the audience hears
Sorry Dave, but this is still incorrect. The majority of the low end from the kick drum itself that the drummer hears is coming from the hole not the batter head. So the drum wedge needs to be in polarity with the mic not phase reversed. Please test this for yourself. Using incorrect polarity to fix feedback is also at the expense of low end for the drummer which will be counterproductive. Using damping, eq, and wedge positioning will provide more useful results.
I have been doing this for many years when the vid was made in 2010 and for many years after.
The vid explains how to test.
It's easy to demonstrate and is the same reason snare bottom is polarity reversed
@@DaveRat I have a lot of respect for how extensive your experience is, but if you listen to an acoustic kick drum with a port. You will notice the low end projects from the port not the batter head and due to the low wavelengths wraps around the drum to the drummers head. If both sides were equal in low end projection you'd get a cancellation. The shell focuses the low end. While your method works in theory it doesn't translate to the sub of the kick drum due to the lower wavelengths diffusing around the drum. I have tried your method many times and come to the same conclusion.
@grimslater if you are not already doing so, have your considered becoming a consultant that high end touring engineers can hire to help find mistakes like this? You can already say that Dave Rat was your first client and put this bass drum case study on your website.
I describe a simple test in the video. I recommend that you try that and see if it aligns with your description of what you think is happening.
I understand what you are describing.
"That a kick drum radiates sound similar to a ported speaker that radiates in-polarity sound in all directions"
And that is a valid assumption and partially correct, some frequencies do radiate that way and it will vary with the tunings of the drum.
The resonant head of a kick drum does time delay and act kind of like a port on a speaker. And as you probably are familiar, The port of a speaker takes the outer polarity rear sound of the speaker and delays it such that it can sum in-polarity with the front of the speaker and add low frequencies.
So in that tuning frequency range the kick should put out an in-polarity -ish signal all the way around.
That said, I think you will find that kick drums in general tend to radiate sound more like a figure eight mic or open back guitar cabinet. Wherein the kick drum is loudest when you stand directly in front of it or directly behind it and when you stand off to the sides it is lower in volume.
This is easily tested by wandering around a kick drum.
The reason it's quieter off to the sides is the same reason and open back guitar cabinet or figure eight mic is quieter off to the sides and that has to do with a substantial amount of frequencies being radiated out-of-polarity on one side and in-polarity on the other side.
If there was no polarity reversal then the sound as you walked around the kick drum would either remain consistent or slowly die out to quieter on one side and louder on the other.
It is the polarity reversal that causes the null wherein you hear lower volumes off to the sides.
So if we can establish that the kick drum puts out somewhat of a figure eight pattern and therefore has an in polarity and out of polarity radiation pattern, we then end up with a scenario where the sound radiated in front is out of polarity with the sound radiated to the back.
This is further magnified by any mic used inside of the kick drum which will pick up definitively a difference in polarity even more pronounced.
If you want to definitively prove this to yourself another way, mic the beater side of a kick drum and then mic the non-beater side and combine those two signals both in and out of polarity. If what you say is correct they should combine best with the most low frequency when they are both in polarity. If you need the polarity reverse one of the mics for them to sum, just like you would with a snare top and snare bottom, then what I describe in the video is the correct description.
As with most all of my videos, I don't ask you to believe but rather I offer you a concept and also the tools to test and understand.
Let me know if you get a chance to do those tests and what you come up with or if anyone else does. I would love to hear the outcomes!
@clownhands I recommend you personally test out and determine what is correct whether it's me or anyone else before taking any knowledge as being fact.
There's lots of incorrect info out there and establishing credibility of the person offering the info and the info itself is wise
The viewpoint of @grimslater is not incorrect, but rather, The assumption that The kick drum is either in or out of polarity and doesn't have a more complex waveform is an oversight
Time warp
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It's just a jump to the left...
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I tried this.... shit works...
Love that and thank you for the update!
And yes I use this concept with excellent results for many decades
Also Dave Rat: Non identical sounds dont interact with each other.
Interesting, except for the fact that no sound tech would ever put the mains behind the drums. In-fact we mount the speakers perpendicular with the kit.
The drumfill can be a wedge or 2 wedges and a sub or whatever. The angle of the speaker makes no difference as the physical angle does not alter the polarity.
In fact, with sealed, ported and horn loaded cans, the polarity of the sound is the same in front and behind the enclosure.
It is only with open back cabinets where the rear of the speaker is exposed that the polarity changes around back
Also, polarity has to do with the two wires that drive the bin. If you want to discuss the air from the speaker than that is not positive and negative and not even considered as polarity. It would be described as pressure and vacuum. And you ideas of flipping polarity on your mikes has nothing to do with the speakers nor will it make any change in the sound. And when you talk mid and high frequencies the wavelengths are very very short and may be hundreds of cycles between your speaker and your drums. Dave I only get annoyed when I see people who have no clue of what they are talking about trying to convince people their theory is correct when it is NOT.@@DaveRat
Dave, next time you set up a PA. If you have ever set one up? Take a live mike and hold it up in front of your main. Now when you hear that loud squeal,, I can assure you flipping the polarity will do NOTHING. And as far as angle. All Mains are placed at least 10 feet forward of the most front stage mike. So, the stage gets no sound at all from the mains. We must add other speaker arrays on stage to feed the first 20 rows of seats with sound as those people can not hear the mains.@@DaveRat
To calculate rhe wavelength of frequencies, the equation is to divide the speed of sound by the frequency involved. Sound travels at approximately 1120 ft per second depending on air temperature.
All those many little cycles before they reach your ears for high and mid frequencies, are easy to calculate
In fact we can even do it in our head
1120hz has a wavelength of approximately 1 ft
112 Hz has a wavelength of approximately 10 ft.
The interactions between wavelengths in the upper frequencies are very audible and easily demonstratable.
The polarity radiated by the front of a speaker is the opposite of the polarity radiated by the rear of that same speaker.
Sticking a mic in a speaker to understand feedback it's kind of like crashing into a wall to learn how to drive.
I do recommend as I describe in the video, turn the kick up in the drum fill until it is on the verge of feedback, where it is overly resonant but not taking off. Then hit the polarity switch. The polarity will typically either increase or decrease the resonance.
Also sit at the drums and hit the kick drum and have someone switch the polarity one way or the other.
If the drum monitor is set to a volume level somewhat similar to the kick drum natural level, you will hear summations are cancellations depending on whether the monitor is the correct polarity
In Snare Polarity section is clearly explained, why most drummers are man. Graph shows proper way of using bass drum. Not by foot.
Funny and you caught that!
.... I only use one nice for drums. Problem solved.
I don't look at it as a problem but rather, a comprehension.
This is one aspect of the bigger picture of understanding that whenever there are multiple versions of the same sound sound audible from any position, that those sounds will interact in such a way that polarity may be relevant.
It could be main PA vs monitors, guitar vs guitar wedge or your own vs vs the in-ears or headphones you are wearing.
Those that fully understand and comprehend the interactions are better equipped to achieve superior results and succeed in the industry.
Don't make different if use
It's interesting when opinions are presented as facts. Credibility of the information source should always be considered
pretty sure you surf
Well yes I' do!!
@@DaveRat 😂
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Out of phase*
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.....yawn.....So it's obvious that Dave myself And everybody else who has done this for 30 plus years is super bored with this business..... If you have any sense go get a real job😊
Yes so boring! Too bad is not infinitely complex
re-recording mixers hollywood are garbage trash at mixing their mixing consoles are garbage trash , i even think skywalker sound is garbage trash now
Interesting and strong perspective