I really like your content, the simplicity of your explication reach a broad range of people of different knowledge levels and help us to understand pretty much everything. Also, the humbleness in the way you talk is what makes me appreciate you and the content much more. Thank you!
I am so glad to have found this video! I just keep noticing that the Qu at church shows clipping early on some channels even though the PFL shows that the channel is well below clipping. It has made me worry that maybe my gain structure is done poorly. But, after seeing its behaviour on this scope, the odd clipping signals makes a lot more sense😅
Thank you for making this. I've had similar issues with the A&H SQ-7, the common mode rejection is so poor I can't really use quiet dynamic mics with it because of that same 60hz buzz. People online on forums are constantly spamming about how awesome it is, but my experience closely lines up with what this video describes.
Strange, I own both consoles and will take the SQ over the x/m32 100% of the time. It’s much cleaner and true, I haven’t heard anyone dislike it’s sound quality
@@IanHind That's just the thing, Everyone on the internet talks about how awesome the A&H sounds but those claims are never tested / analyzed (until now). I'm not saying the A&H consoles sound bad for most cases, i'm just saying they don't sound any better than an x32, and that's just how good budget digital consoles are theses days. when the show starts, nobody should be able to even tell what console is running if we've done our jobs right.
So the A&H has transient suppression diodes on the inputs that start clipping at approx 12V. I don't have the schematic for the QU-16, but I have it for the X32. Looking at the inputs of the X32, there are transient suppression diodes connected to the +/-15V rails. So if you push the Behringer inputs a bit harder I would expect it to clip without warning (nor red LED) just like the QU-16.
A friend's bar here bought the Qu16 twice, well almost. Had to replace the mainboard and some other components twice in 5 years and sold it after it came back from the second repair. Meanwhile the X32 in another friend's bar is going strong for about 5 years as well. Don't know if they got a lemon. Both consoles sound decent but I prefer the X32 slightly, M32 is a little better, Yamaha QL3 sounded a bit nicer againm especially the FX are way better, but we're already at 10x budget. Behringer Wing is a beast for the money.
Its totally hilarious having seen this clip from awhile ago and forgetting that i commented on it, and thinking that i was glad i bought the Midas m32. ...then going through the comments only to discover i already had commented. I must be loosing my mind! 😂 i still love the content though regardless.
I fully expected them to feedback like crazy at any moment, just by instinct. Imagine that noice on stage. Thanks. I will check my gear at max gain, too.
That's interesting. The no clip light clipping on the QU. Regarding the Y-split noise from the QU to the B. I often have acts come in and use a Y-split to create a mock monitor split for a vocal. I wonder if this is also an issue when splitting this way on the one console. Thanks again for this series. It's a real eye opener.
Don't iso splitters exist to prevent the consoles from being able to interfere with each other in this manner? With a Y-splitter you're not only halving the impedance, but also allowing a potential path for electricity to go from one console to the other in a way yuou don't necessarily want, which is why you generally want a transformer in there, no?
AC (music) travels both directions 8n wires and both directions through transformers. The transformers offer DC isolation not AC isolation. A transformer will not alter what is occuring here but an active splitter would prevent one board from loading down the other.
I’m curious if the buzz is an imperfect CMRR that shows up when the inputs are connected with a straight ahead Y between the two consoles. The buzz reminds me of a ground loop with a switching power supply involved.
Not sure but cmrr is to fix noise from cables, this issue seems 6o be internal as it happens even when the resistor is plugged directly into the console, no cable.
I use the QU a lot and love it. I think it sounds awesome for the money. I do find the metering a little odd though. The individual channel meters seem to show the clip light way too early. If you PFL, the main meter shows no where near clip and seems to be closer to actual clip.
The more I see from you, the more digital scares me. Would be neat to see a comparison of say the x32 to a better quality analog board, and would also be interesting to compare some of the same things you do, but with a couple popular recording interfaces. Or maybe even say a UA Apollo to the X32. Stole your live mixing idea with putting like- minded channels to stereo busses with a comp dual mono for studio mixing (analog), and that works very well and is really fun too. I'm joining!
Digital is awesome but also should not be taken as automatically better. When using digital, try and convert once and stay digital, avoid multiple conversions with signals other than efx. Never clip digital, be wary and test and listen as digital is awesome and also temperamental. And most of all, choose the simplest path that gets the job done, if you want the best results, regardless of digital or analog.
@@DaveRat Thanks, sound advice. The current workflow has a couple steps of conversion, like analog to digital, then digital to analog through the analog board and back to another AD conversion for the mix. Then I listen on another system and "master" in the digital realm. So I have a couple conversion points there and I don't hear a problem, but I think you are alluding to something. Might also add that I've been a programmer for about 25 years and have been basically starting at computer screens forever and whatever I can do to get away from that is a huge plus for me. So analog mixing and less mouse shit means I can have a lot more fun with music. Thanks, and looking for whatever you come up with that you think is interesting. It's all super interesting to me.
The noise on the Behringer being all in the really high frequencies kind of makes sense with my subjective limited experience with Behringer mixers. They tended to sound like there was some boost right at the highest frequencies I could hear. Other brands sounded more flat to me. This could easily be tested with a scope but I don't have one (or a reference mixer anymore). The sound wasn't particularly unpleasant but my boss also said the stuff we recorded with the Behringer gear sounded more airy and the cymbals stood out more
The fact that the clipping on the one mixer is affecting the signal going to the other, likely means that there is some sort of input clamping going on (like a protection diode, etc). The bench source is probably 50 ohms, so when driving the A/H console hard the input impedance is momentarily dropping down in that range at the peaks. Typically the active preamp circuit should have quite high input impedance, even if the output was clipping, so I'm guessing there is some sort of voltage/ESD protection at the input that is starting to activate. The clipping indicator light is probably only checking the voltage at the preamp output (probably digitally after the ADC), and so it doesn't know that the input is clamping, because even though distorted, the preamp attenuation keeps the preamp output below the ADC full scale range. With a higher preamp gain, you would never see this problem as the preamp output would clip first (which the system would recognize). It does seem like a design flaw if this is normal...it should be designed such that at the lowest preamp gain setting, the preamp output should clip first (so the clip indicator will work) OR they need to add an analog clip detector directly at the input that triggers right before the voltage protection start to clamp.
I was going to write the same thing. The SSM2019 preamp IC’s data sheet (probably not what”s in the QU16 but it’s pretty representative) shows 12 volt zener clamp diodes on the input for ESD and over voltage protection. I’d be suspicious that conduction of these diodes also cause the phantom ‘crack’ that QU16s are known for, that sounds like the clipping might actually be the excessive voltage getting onto a ground bus. It isn’t clipping the A to D converter but the preamp, but only when it is at its lowest gain setting. The shape of the clipping looks like something happening in the mic preamp where one leg is running out of feedback voltage. When the zener diodes conduct, if they aren’t exactly symmetrical it could cause the phantom blocking capacitors to slightly bias to one side, creating the asymmetrical preamp clip that isn’t detected because it’s clipping before the ADC. Just a thought. You’d need to pop the lid off and ‘scope the raw signals inside to figure it out. But it definitely looks like clamping diode conduction, but at a signal level I’ve only seen when you pop a capsule on or off of an energized condenser mic.
@@dale116dot7 yeah sounds reasonable. Would need to see the schematic. Seems they should have raised the min preamp gain setting if they couldn't handle that large of a signal.
@@DaveRat I'm completely with @tompettytribute Looks like a ESD protection diode clamping before the preamp. The ADC won't notice so peak led won't light. Typical threshold values for protection diodes are +/-14V. So 9.3V peak to peak shouldn't hit the limit, but maybe they're using another protection method. I'm thinking on bidirectional TVS protection diodes...
👍 it's cool studying why is interesting, possibly from the " is there a simple mod/fix" perspective. Sometimes finding an anomalies inspires a design fix or change in future products as well
For reference 9.3volts = +21dBu which is pretty hot for an input signal. You'd be hard pressed to get a microphone to output that kind of level, but if you're taking input from something like a DJ deck with a hot output you might need to grab a pad of some kind.
That's 9.3 rms, we are looking at peak to peak voltages. 9.3 rms would be over 23 volts peak to peak. 9.3 volts peak to peak is only 3.28 volts rms or about 12.5 dbu. While still not a low level signal, it is well below the rated input capabilities
I've been looking for board reviews and can't find anyone testing noise levels! Finally found someone doing it! Thank you! Also, on my speakers and ears, the noise was louder every time the visual showed more noise. My speakers are very cheap, but my ears a younger. Maybe one or both of those things makes a difference?
i really like your content as very informative, one piece of PA kit i found was a total game changer was martin audios superb MLA as made setting up so much simpler than keep adjusting boxes to get the coverage
This is not a correct comparison . you should have not have both on and plugged into the same source via a separate mixer. You only increase the chance of interference between the units like you demonstrated at 14:40.you should compare the noise with only 1 unit plugged in and connected to the source. The Behringer is a more cheaper equipment therefore more prone to pick up interference from other units connected to the same chain.
Do you really believe that the results will change? If indeed having both mixers plugged in changes the outcome, would that not be a huge issue with the mixer? When you use a mixer at a show do you make sure no other gear is plugged in?
With regards to clipping the X32, clippting the preamp and output stages are a bad thing, giving you flat top square waves. If you route a Channel to BUS to StereoLR, but you don't clip neither the input nor the StereoLR (XLR in and out), but instead clip the BUS do you still get the same clipping artifacts? Seeing as the X32 theoretically has infinite dynamic range given that is uses a 40bit floating point?
I recently stumbled across posts of XLR vs DMX cables and about their impedances: xlr 75ohm and dmx 110ohm, I tried to google more information about xlr vs dmx cables and impedance of xlr cables being 75ohm but can’t find good explanations. Do you have any videos or articles explaining the reasoning behind xlr having 75ohm and dmx having 110ohm impedance ? And differences between xlr and dmx cables ?
I wish I fully understood enough to share info. That said, I learn by testing and my perspective is that if it has no real world negative impact for the application at hand, then the differences can be ignored. I have not used dmx for mic cables but have much experience using cat5e for analog audio and all tests result in cat5e of the same wire gauge performing better than mic cables with freq response, noise rejection and transmitting over longer distances.
I use DMX cable for the lighting in our Church and I had always heard that you shouldn't use regular XLR cables for DMX. I do know that for low impedance mic cables, 75 ohms makes a lot more sense because the impedance should be low for mic cables. The DMX protocol is based on the RS-232 protocol so apparently the experts decided that 110 ohms worked best for this type cable. Also, DMX cables can be very long. The one I use is 150 feet. I know this is not a real good explanation, but hope it helps : )
Dmx can be noisy so foil shield helps reduce it messing with audio. For short to mid length cables, it makes little difference. I did a vid testing AES3 down mic cables, AES cable and cat5e. Turns out the audio mic cables were better at AES3 than the AES cables and Cat5e was best. Turns out that larger diameter cables tend to be better at everything than thinner diameter cables regardless of of whether they are mic AES3, dmx, or cat5.
Interesting that in gain test (7:40 - ish) the A&H has a 60Hz earth hum and the Behringer instead adds a 520Hz tone (which had its own harmonics, making it sound a little square?). Perhaps the A&H picking up the hum is something related to the circuitry that causes weirdness through the Y cable when connected to the second console?
0:40 Now I'm curious about your progress through the world of sound (how you started, how you improved, how you kept learning, etc). Have you ever talked or written about this? Also, after about four decades of working in sound, how do you deal with the limitations age adds to your ears?
It seems to me like the 60Hz hum is present in the x32 as well, but it is buried by the extra noise. Having used both consoles, I do find in regular use (not needing more than 30dB gain) that the QU sounds better because it's cleaner at the more standard gain levels.
It would be interesting to compare these two consoles via the remote stage boxes. The preamps on the A&H AB/AR stageboxes are a better quality than the local ones on the Qu series. The Qu stage boxes use the GLD preamps, and offer an additional pad control. These are still not premium preamps, but still they are better than the onboard Qu series preamps.
@@DaveRat I fully agree. Thanks again for making these videos. Always informative, and made me go out and do some comparisons on some of my own mixers.
If the x32 has some noise in the very high frequency range on the outputs; - it would be interesting to see if using class-d switch mode amps in the rig as well if that triggers the amp to introduce potential noise/distortion - as we know some class-d amps hate very high frequency on the input.... even causing some to go DC 🤷♂️ it seems like a potential way to add further exponential noise/distortion/artefacts....
True that many class d don't like high levels of HF. Based on what I tested, the HF noise from the x32 may be audible but is not at a high level. And most likely well below the level that would cause issues other than audible annoying
@@DaveRat yep. anything is audible if you crank up the gain behind it enough. But what matters is the relative amplitude to the program content, which should be easily >>60dB higher. Can't see it causing amplifier issues.
I guess the noise on the QU16 would still be prevalent on 240v @ 50hz? Just curious as I've never come across it. Perhaps none of my input voltages have been high enough.
@@DaveRat How bad is the noise? I'm guessing the audience will never notice (too much other noise even when nothing is going though the system), but if you're doing recording, that might be a different story.
It depends, in my experience I have done comedy acts and acoustic shows where noise floor is a concern. Having a hiss from the PA in a silent theater hush is a bummer. I have also done shows where amplifier fan noise is an issue. I would think plays and orchestral shows would be a concern as well
@@DaveRat I was thinking "concert" but that's a good point. Still, it seems strange to me. I can understand hiss if you have channels up and all those preamps feeding the bus, but a muted output? That's a straight up design issue that should be controllable.
The title of this video should be "Why the X32 works better in small venues and in-ear racks than the QU16/32." Just for how the QU's preamps clamp down on the input like they do. If Behringer hadn't screwed up on the service end of the industry, they would have held a better reputation in the market. Where I work, we took in an S16 on a repair. Total nightmare and a complete loss in faith in that company by my boss. He will never own a piece of their gear. Such a shame.
From all the QU and x32 testing, one aspect that stands out is that digital clip sucks. The metering on the QU tends to offer more headroom on the inputs with mic level signals. But mainly it's all about the engineers knowing how each console meters and not doing things that sound bad
Dave, what composition is the resistor you're using? You should ensure that you're using a wire wound or at least a metal film for the quietest operation/most accurate testing.
Hello, Dave. Firstly, many thanks for sharing your knowledge and wisdom. In your opinion or from your experience, how does the Midas MR18 compare to the Allen & Heath Qu-SB in terms of their sound quality, especially regarding their preamps, channel strips, effects and noise levels [input, output and digital (via USB)]? Thanks again, and all the best. ⚡⚡⚡
Regarding the clipping. What is the output impedance of your generator? I guess quite low. Probably lower than any mic. Maybe you should wire a 600ohm resistor in series with the generator, and repeat the test. Also the mixers input could be stressing the generator for whatever reason, could that be the source of the distortion?
Hmmm, the clip is the same when driven by a console output. A mic would never have that high of an output so that is irrelevant for tests at these levels. If the console is temperamental in ways that other consoles are not, and even if it was to distort with some sources and not others, that still remains to be an issue. So, if I have to put a resistor in line to make it work, that would just further prove the issue
@@DaveRat "the clip is the same when driven by a console output" pretty much proves your point. Thanks for the answer. Thanks for incredible content, cool, cool!
👍👍 and good point on checking to make sure it's not an issue with the generator. I do test that as I am suspicious of everything including non "audio" gear driving audio gear
I don't know if it's my younger ears, but the noise floor on the X32 seemed louder? Could this be the video/recording? The Allen and heath obviously has the horrible noise at higher voltages, but the noise on the x-32 sounded overall louder
Loudness is a perceptive and scope readings can be deceptive. Also, since the noise has differing frequency content, the perception of louder will be dependant on the bandwidth and freq response of the sound source you use to listen
@@DaveRat good points, I hadn't fully thought about that, I was listening through headphones and would have hoped it to be reasonably representative, so interesting to see that I hear it a little differently to you!
@@DaveRat PS, you're an absolute hero in my house, your videos are absolutely fantastic, and the way you show very complex systems/concepts simply is truly magnificent!
It's true what you say Dave with regards to making crappy gear sound great. On Drumeo, Jarred takes literally a toy drum kit and puts some half decent skins on and "hey presto" ...it came up pretty good. With regards to the Q series console, that buzzing could be earthing differential between maybe the logic board and the AD-DA converters... maybe? 🤷🏻♂️Maybe some phantom voltage leakage being drawn from the input despite it being off? Dunno but it's great how you find these quirks regarding things to watch out for. I'm still happy with my little Midas M32 best bang for buck me thinks. 😉
Hi thanks for sharing knowledge! Please tell why xenyx q1204 makes noise when fader is fully upward Because my xenyx x1204usb is creating same noise when volume fader is full or when gain is full, and this happens without putting any input in channels, I'm only connecting output to speaker any when putting fader and gain to full it makes same noise as you are using for this video I'm not sound guy so I've no idea why it makes... Is there any issue with my analog mixer or does they create this noise when volume fader or gain is full?
All consoles do that and adding lots of gain to a channel with no input will have even more noise than when there is an input load. The Xenyx is not a very quiet mixer, it's is more quiet than an x32 or qu16 though, for the same gain
Hey Dave, Thanks for all your interesting and informative experiments! I've never used the X32, but have used a Qu-32, so I'm not commenting on the 'which desk is better'. I'm not up on electronics, but I see info from a reputable place online that mic level is up to around 0.001volt, and line level is up to 1.00volt. OK, there might be some gear that pushes the boundaries a bit, but is the 9.3volts in the range of concern for normal mics and electronic musical instruments? Genuine question. Many X32 and Qu-series users run Ethernet stageboxes. In A&H gear, I understand the stagebox has different preamps to those in the desk. Would be interesting to see if the same issue persists with them?
I am using peak to peak voltages as they are easier to read on the scope. Usually people refer to rms voltage. 9.3 p to p is about 3.3 v rms and music typically has 3 to 1 to 10 to 1 peaks. So a 1 volt rms signal will often have a peaks well exceeding 3.3 volts rms
Thanks @@DaveRat that puts it in perspective for me now. Two takeaways for me: Qu users should avoid crazy hot input signals; and maybe we shouldn't be too quick to overlook good old analogue :-)
The big issue for me was the QU was distorting even when the clip light was not lighting. And the test inputs are not that hot, they are of a level you would expect from an audio playback device with a +4 output, which is common
@@DaveRat Certainly one to look out for. Think the only time I've heard clipping on the Qu was when I had made a mess of on-board compressor settings on a vocal channel. Audible clipping but no clip light. Thought the vocalist was too close & loud on the mic, but then I checked the DAW recording (signal tapped-off directly after the pre-amp), and it was clean. Guess it depends where the clip light is positioned in the circuit, but it's another one to look out for.
@@DaveRat Please do, since the QU series is really old tech and comes from the dark ages at A&H. Their new stuff is super good though. And if possible, please also add a DX168, so we can have the dLive preamps in the mix as well (which would be the quivalent to the Midas Pro Preamps).
Will ponder that. But more importantly, rather than me testing it for you and others, I am highlighting issues and using relatively inexpensive test gear and simple methods to do so such that you and others are able to do the tests you desire on gear of interest. My videos are to teach you how to test more than for you to observe the tests
Please check out an SQ series Allen Heath your not comparing apples to apples with the Qu being a considerably less expensive console than x32. That said I love your videos!
Well it was lol. There have been two price increases since I purchased an SQ and I believe the x32 dropped since the Wing came out. Having owned multiple Behringer, Yahama and Allen Heath consoles the SQ has been my favorite so far.
Thank you a lot for this (another) great and super interesting video. Very strange and impressive how the A&H reacts to higher voltages. Do you by chance have any experience with Presonus recent mixers (series III and III S) ? I'm quite interested by their stuff but I never see any Presonus gear in venues or festivals
So do I, as I own one, but, not the point of the video. It's obvious the M32 would perform better, but the X32 is more popular due to the price point. I prefer my M32 to the X32 any day of the week, but I'll rock the shit out of whatever board is in front of me to the best of my ability.
@@rickdagrexican7351 The sound is my first priority, but after that things like look, feel, workflow, and build quality factor into it. I'll take the QU-16 over the X32 any day of the week even though the M32 supersedes both of them and isn't out of the same price range...whats a couple hundred more when ur spending thousands?
Interesting. All the tests I did seem to show that the "better" in "better preamps" means lower noise. And low noise is good but the actual sound appears to be very close to identical.
I love Dave’s channel. He is completely humbled by his approach to gear and doesn’t have any biases
Thank you!!!
I really like your content, the simplicity of your explication reach a broad range of people of different knowledge levels and help us to understand pretty much everything. Also, the humbleness in the way you talk is what makes me appreciate you and the content much more. Thank you!
Thank you thank you!
I am so glad to have found this video! I just keep noticing that the Qu at church shows clipping early on some channels even though the PFL shows that the channel is well below clipping. It has made me worry that maybe my gain structure is done poorly. But, after seeing its behaviour on this scope, the odd clipping signals makes a lot more sense😅
🤙👍🎛️
Thank you for making this. I've had similar issues with the A&H SQ-7, the common mode rejection is so poor I can't really use quiet dynamic mics with it because of that same 60hz buzz. People online on forums are constantly spamming about how awesome it is, but my experience closely lines up with what this video describes.
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Strange, I own both consoles and will take the SQ over the x/m32 100% of the time. It’s much cleaner and true, I haven’t heard anyone dislike it’s sound quality
@@IanHind That's just the thing, Everyone on the internet talks about how awesome the A&H sounds but those claims are never tested / analyzed (until now). I'm not saying the A&H consoles sound bad for most cases, i'm just saying they don't sound any better than an x32, and that's just how good budget digital consoles are theses days. when the show starts, nobody should be able to even tell what console is running if we've done our jobs right.
I think the way the gain structure and input clip is setup on the Allen and Heath, it helps engineers not create clip problems
@@magoostus SQ and Qu are two entirely different animals. No comparison.
So the A&H has transient suppression diodes on the inputs that start clipping at approx 12V. I don't have the schematic for the QU-16, but I have it for the X32. Looking at the inputs of the X32, there are transient suppression diodes connected to the +/-15V rails. So if you push the Behringer inputs a bit harder I would expect it to clip without warning (nor red LED) just like the QU-16.
A friend's bar here bought the Qu16 twice, well almost. Had to replace the mainboard and some other components twice in 5 years and sold it after it came back from the second repair. Meanwhile the X32 in another friend's bar is going strong for about 5 years as well. Don't know if they got a lemon. Both consoles sound decent but I prefer the X32 slightly, M32 is a little better, Yamaha QL3 sounded a bit nicer againm especially the FX are way better, but we're already at 10x budget. Behringer Wing is a beast for the money.
Love watching you test these digital consoles comparing noise and and levels. Keep up the good work!
Thank you Josh!
Its totally hilarious having seen this clip from awhile ago and forgetting that i commented on it, and thinking that i was glad i bought the Midas m32. ...then going through the comments only to discover i already had commented. I must be loosing my mind! 😂 i still love the content though regardless.
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Wow! SUpervideo! And you're very right, it's the person who makes the sound, not the equipment...
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No other father-daughter video's, Dave? Hahaha! I liked them!
Next time she is back from school, will do one
I fully expected them to feedback like crazy at any moment, just by instinct. Imagine that noice on stage. Thanks. I will check my gear at max gain, too.
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That's interesting. The no clip light clipping on the QU. Regarding the Y-split noise from the QU to the B. I often have acts come in and use a Y-split to create a mock monitor split for a vocal. I wonder if this is also an issue when splitting this way on the one console. Thanks again for this series. It's a real eye opener.
👍👍👍
Don't iso splitters exist to prevent the consoles from being able to interfere with each other in this manner? With a Y-splitter you're not only halving the impedance, but also allowing a potential path for electricity to go from one console to the other in a way yuou don't necessarily want, which is why you generally want a transformer in there, no?
AC (music) travels both directions 8n wires and both directions through transformers.
The transformers offer DC isolation not AC isolation. A transformer will not alter what is occuring here but an active splitter would prevent one board from loading down the other.
I’m curious if the buzz is an imperfect CMRR that shows up when the inputs are connected with a straight ahead Y between the two consoles. The buzz reminds me of a ground loop with a switching power supply involved.
Not sure but cmrr is to fix noise from cables, this issue seems 6o be internal as it happens even when the resistor is plugged directly into the console, no cable.
I use the QU a lot and love it. I think it sounds awesome for the money. I do find the metering a little odd though. The individual channel meters seem to show the clip light way too early. If you PFL, the main meter shows no where near clip and seems to be closer to actual clip.
Hey hey Nick and yes, that's what I saw as well
The more I see from you, the more digital scares me. Would be neat to see a comparison of say the x32 to a better quality analog board, and would also be interesting to compare some of the same things you do, but with a couple popular recording interfaces. Or maybe even say a UA Apollo to the X32. Stole your live mixing idea with putting like- minded channels to stereo busses with a comp dual mono for studio mixing (analog), and that works very well and is really fun too. I'm joining!
Digital is awesome but also should not be taken as automatically better.
When using digital, try and convert once and stay digital, avoid multiple conversions with signals other than efx. Never clip digital, be wary and test and listen as digital is awesome and also temperamental.
And most of all, choose the simplest path that gets the job done, if you want the best results, regardless of digital or analog.
@@DaveRat Thanks, sound advice. The current workflow has a couple steps of conversion, like analog to digital, then digital to analog through the analog board and back to another AD conversion for the mix. Then I listen on another system and "master" in the digital realm. So I have a couple conversion points there and I don't hear a problem, but I think you are alluding to something. Might also add that I've been a programmer for about 25 years and have been basically starting at computer screens forever and whatever I can do to get away from that is a huge plus for me. So analog mixing and less mouse shit means I can have a lot more fun with music. Thanks, and looking for whatever you come up with that you think is interesting. It's all super interesting to me.
Do it and let me know how it goes!!
A comparaison of all the large/pro console brands would be amazing! (Digico SD/Quantom, dLive, LV1, Pro x, Avid, SSL, Soundcraft)
Btw, thanks alot for these videos! It's great!
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I'm very interested in seeing if the issues on the QU continue onto their premium models like the dLive.
I would think the addition of a pad and digital trim, If added, would alter the results.
If I come across one of the consoles I will test
Long time user of QU-24. Great mixer and recording interface.
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The noise on the Behringer being all in the really high frequencies kind of makes sense with my subjective limited experience with Behringer mixers. They tended to sound like there was some boost right at the highest frequencies I could hear. Other brands sounded more flat to me. This could easily be tested with a scope but I don't have one (or a reference mixer anymore). The sound wasn't particularly unpleasant but my boss also said the stuff we recorded with the Behringer gear sounded more airy and the cymbals stood out more
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I noticed the same thing
Thank you Fedge
I don't have an X32 (yet) so I can't test for myself, but would applying a high pass on all inputs negate that effect?
Great video as always. But that SHIRT is the bomb!!!
Ha!!! Awesome!
The fact that the clipping on the one mixer is affecting the signal going to the other, likely means that there is some sort of input clamping going on (like a protection diode, etc). The bench source is probably 50 ohms, so when driving the A/H console hard the input impedance is momentarily dropping down in that range at the peaks. Typically the active preamp circuit should have quite high input impedance, even if the output was clipping, so I'm guessing there is some sort of voltage/ESD protection at the input that is starting to activate. The clipping indicator light is probably only checking the voltage at the preamp output (probably digitally after the ADC), and so it doesn't know that the input is clamping, because even though distorted, the preamp attenuation keeps the preamp output below the ADC full scale range. With a higher preamp gain, you would never see this problem as the preamp output would clip first (which the system would recognize). It does seem like a design flaw if this is normal...it should be designed such that at the lowest preamp gain setting, the preamp output should clip first (so the clip indicator will work) OR they need to add an analog clip detector directly at the input that triggers right before the voltage protection start to clamp.
I was going to write the same thing. The SSM2019 preamp IC’s data sheet (probably not what”s in the QU16 but it’s pretty representative) shows 12 volt zener clamp diodes on the input for ESD and over voltage protection. I’d be suspicious that conduction of these diodes also cause the phantom ‘crack’ that QU16s are known for, that sounds like the clipping might actually be the excessive voltage getting onto a ground bus. It isn’t clipping the A to D converter but the preamp, but only when it is at its lowest gain setting. The shape of the clipping looks like something happening in the mic preamp where one leg is running out of feedback voltage. When the zener diodes conduct, if they aren’t exactly symmetrical it could cause the phantom blocking capacitors to slightly bias to one side, creating the asymmetrical preamp clip that isn’t detected because it’s clipping before the ADC. Just a thought. You’d need to pop the lid off and ‘scope the raw signals inside to figure it out. But it definitely looks like clamping diode conduction, but at a signal level I’ve only seen when you pop a capsule on or off of an energized condenser mic.
@@dale116dot7 yeah sounds reasonable. Would need to see the schematic. Seems they should have raised the min preamp gain setting if they couldn't handle that large of a signal.
Interesting
@@DaveRat I'm completely with @tompettytribute
Looks like a ESD protection diode clamping before the preamp. The ADC won't notice so peak led won't light.
Typical threshold values for protection diodes are +/-14V. So 9.3V peak to peak shouldn't hit the limit, but maybe they're using another protection method. I'm thinking on bidirectional TVS protection diodes...
👍 it's cool studying why is interesting, possibly from the " is there a simple mod/fix" perspective.
Sometimes finding an anomalies inspires a design fix or change in future products as well
Thanks a lot! Also interesting MR18/M32 vs QU16
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I'm going to try this with an isolated split amazing what a good transformer will do
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Thx again. Very interesting and inspiring. You rock!
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For reference 9.3volts = +21dBu which is pretty hot for an input signal. You'd be hard pressed to get a microphone to output that kind of level, but if you're taking input from something like a DJ deck with a hot output you might need to grab a pad of some kind.
That's 9.3 rms, we are looking at peak to peak voltages. 9.3 rms would be over 23 volts peak to peak.
9.3 volts peak to peak is only 3.28 volts rms or about 12.5 dbu.
While still not a low level signal, it is well below the rated input capabilities
I've had some really hot bass and keyboard signals in the past. I would imagine one of those instruments could also push such a high voltage?
The voltages are just pretty normal line level
I've been looking for board reviews and can't find anyone testing noise levels! Finally found someone doing it! Thank you!
Also, on my speakers and ears, the noise was louder every time the visual showed more noise. My speakers are very cheap, but my ears a younger. Maybe one or both of those things makes a difference?
Cool. Some of the noise is a lower frequency so speakers with a more full range response and more lows will change things
@@DaveRat thanks! If you can get your hands on more boards to test, it would be greatly appreciated!
i really like your content as very informative, one piece of PA kit i found was a total game changer was martin audios superb MLA as made setting up so much simpler than keep adjusting boxes to get the coverage
Thank you and very cool
This is not a correct comparison . you should have not have both on and plugged into the same source via a separate mixer. You only increase the chance of interference between the units like you demonstrated at 14:40.you should compare the noise with only 1 unit plugged in and connected to the source. The Behringer is a more cheaper equipment therefore more prone to pick up interference from other units connected to the same chain.
Do you really believe that the results will change?
If indeed having both mixers plugged in changes the outcome, would that not be a huge issue with the mixer?
When you use a mixer at a show do you make sure no other gear is plugged in?
With regards to clipping the X32, clippting the preamp and output stages are a bad thing, giving you flat top square waves. If you route a Channel to BUS to StereoLR, but you don't clip neither the input nor the StereoLR (XLR in and out), but instead clip the BUS do you still get the same clipping artifacts?
Seeing as the X32 theoretically has infinite dynamic range given that is uses a 40bit floating point?
Yeah, I think you can overload the summing buss, to test, send all channels hot but clean to 1 bus. Overload should be audible
On the qu. I use XLR to jack for line level in because of no 20db pad.
And the preamp is very easy to clip
By using the XLR in.
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I recently stumbled across posts of XLR vs DMX cables and about their impedances: xlr 75ohm and dmx 110ohm, I tried to google more information about xlr vs dmx cables and impedance of xlr cables being 75ohm but can’t find good explanations. Do you have any videos or articles explaining the reasoning behind xlr having 75ohm and dmx having 110ohm impedance ? And differences between xlr and dmx cables ?
I wish I fully understood enough to share info.
That said, I learn by testing and my perspective is that if it has no real world negative impact for the application at hand, then the differences can be ignored.
I have not used dmx for mic cables but have much experience using cat5e for analog audio and all tests result in cat5e of the same wire gauge performing better than mic cables with freq response, noise rejection and transmitting over longer distances.
I use DMX cable for the lighting in our Church and I had always heard that you shouldn't use regular XLR cables for DMX. I do know that for low impedance mic cables, 75 ohms makes a lot more sense because the impedance should be low for mic cables. The DMX protocol is based on the RS-232 protocol so apparently the experts decided that 110 ohms worked best for this type cable. Also, DMX cables can be very long. The one I use is 150 feet. I know this is not a real good explanation, but hope it helps : )
Dmx can be noisy so foil shield helps reduce it messing with audio.
For short to mid length cables, it makes little difference.
I did a vid testing AES3 down mic cables, AES cable and cat5e. Turns out the audio mic cables were better at AES3 than the AES cables and Cat5e was best.
Turns out that larger diameter cables tend to be better at everything than thinner diameter cables regardless of of whether they are mic AES3, dmx, or cat5.
That shirt is badass...how can I get? Thanks Dave for all you do brother!!
Happy New Year 👍💯👀
👍👍👍 thank you. Maybe we will make some of those shirts
Interesting that in gain test (7:40 - ish) the A&H has a 60Hz earth hum and the Behringer instead adds a 520Hz tone (which had its own harmonics, making it sound a little square?). Perhaps the A&H picking up the hum is something related to the circuitry that causes weirdness through the Y cable when connected to the second console?
0:40 Now I'm curious about your progress through the world of sound (how you started, how you improved, how you kept learning, etc). Have you ever talked or written about this? Also, after about four decades of working in sound, how do you deal with the limitations age adds to your ears?
Maybe do a search for Dave rat blog. I've done a few but Roadies in the midst I wrote much about all of that and more.
It seems to me like the 60Hz hum is present in the x32 as well, but it is buried by the extra noise.
Having used both consoles, I do find in regular use (not needing more than 30dB gain) that the QU sounds better because it's cleaner at the more standard gain levels.
Interesting. I have not used either for live mixing so I can only estimate what would happen
It would be interesting to compare these two consoles via the remote stage boxes. The preamps on the A&H AB/AR stageboxes are a better quality than the local ones on the Qu series. The Qu stage boxes use the GLD preamps, and offer an additional pad control. These are still not premium preamps, but still they are better than the onboard Qu series preamps.
To the best of my understanding, whatever is used for inputs and outputs determines the sound quality and noise. The surface is just control.
@@DaveRat I fully agree. Thanks again for making these videos. Always informative, and made me go out and do some comparisons on some of my own mixers.
Very cool
If the x32 has some noise in the very high frequency range on the outputs;
- it would be interesting to see if using class-d switch mode amps in the rig as well if that triggers the amp to introduce potential noise/distortion - as we know some class-d amps hate very high frequency on the input.... even causing some to go DC 🤷♂️ it seems like a potential way to add further exponential noise/distortion/artefacts....
True that many class d don't like high levels of HF. Based on what I tested, the HF noise from the x32 may be audible but is not at a high level. And most likely well below the level that would cause issues other than audible annoying
@@DaveRat yep. anything is audible if you crank up the gain behind it enough. But what matters is the relative amplitude to the program content, which should be easily >>60dB higher. Can't see it causing amplifier issues.
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Great vid and super interesting.
Thank you Sol!
I guess the noise on the QU16 would still be prevalent on 240v @ 50hz? Just curious as I've never come across it. Perhaps none of my input voltages have been high enough.
I would think so, but would need to test to know
So, if you were to run the signal fom the signal generator straight to the preamps and not through the Y cable would the results be different?
Nope.
Curious about all the noise on the X32 even when muted. Live, I can understand, but muted?
Whether the issue applies is up to you, and the noise is still there when not muted
@@DaveRat How bad is the noise? I'm guessing the audience will never notice (too much other noise even when nothing is going though the system), but if you're doing recording, that might be a different story.
It depends, in my experience I have done comedy acts and acoustic shows where noise floor is a concern. Having a hiss from the PA in a silent theater hush is a bummer. I have also done shows where amplifier fan noise is an issue. I would think plays and orchestral shows would be a concern as well
@@DaveRat I was thinking "concert" but that's a good point. Still, it seems strange to me. I can understand hiss if you have channels up and all those preamps feeding the bus, but a muted output? That's a straight up design issue that should be controllable.
Yeah, a noisy muted output is not ideal. Though using an aes3 or digital output to the amps would solve that
The title of this video should be "Why the X32 works better in small venues and in-ear racks than the QU16/32." Just for how the QU's preamps clamp down on the input like they do. If Behringer hadn't screwed up on the service end of the industry, they would have held a better reputation in the market. Where I work, we took in an S16 on a repair. Total nightmare and a complete loss in faith in that company by my boss. He will never own a piece of their gear. Such a shame.
From all the QU and x32 testing, one aspect that stands out is that digital clip sucks. The metering on the QU tends to offer more headroom on the inputs with mic level signals.
But mainly it's all about the engineers knowing how each console meters and not doing things that sound bad
Nice video!! Would ever show possible work arounds of these issues? Dealing with a high noise floor or the power issue with the Allen & Heath
Hmmm, lots of possibilities
Dave, what composition is the resistor you're using? You should ensure that you're using a wire wound or at least a metal film for the quietest operation/most accurate testing.
You wouldn't want to use a wire wound due to the added induction in its construction .
Metal film and since I am doing comparisons, not specific measurements, everything sees the same.
Hello, Dave. Firstly, many thanks for sharing your knowledge and wisdom. In your opinion or from your experience, how does the Midas MR18 compare to the Allen & Heath Qu-SB in terms of their sound quality, especially regarding their preamps, channel strips, effects and noise levels [input, output and digital (via USB)]? Thanks again, and all the best. ⚡⚡⚡
Hey hey Victor! Ha. Dunno. Never used either.
@@DaveRat Thanks, Dave.
Regarding the clipping. What is the output impedance of your generator? I guess quite low. Probably lower than any mic. Maybe you should wire a 600ohm resistor in series with the generator, and repeat the test. Also the mixers input could be stressing the generator for whatever reason, could that be the source of the distortion?
Hmmm, the clip is the same when driven by a console output. A mic would never have that high of an output so that is irrelevant for tests at these levels.
If the console is temperamental in ways that other consoles are not, and even if it was to distort with some sources and not others, that still remains to be an issue.
So, if I have to put a resistor in line to make it work, that would just further prove the issue
@@DaveRat "the clip is the same when driven by a console output" pretty much proves your point. Thanks for the answer. Thanks for incredible content, cool, cool!
👍👍 and good point on checking to make sure it's not an issue with the generator. I do test that as I am suspicious of everything including non "audio" gear driving audio gear
@@DaveRat Have you try another input of the qu16? The distortion (not clipping and asymmetric) is gain dependant?
The clipping/dist is before the gain, so gain raises and lowers the issue but can not make it go away.
All inputs are the same
I don't know if it's my younger ears, but the noise floor on the X32 seemed louder? Could this be the video/recording? The Allen and heath obviously has the horrible noise at higher voltages, but the noise on the x-32 sounded overall louder
Loudness is a perceptive and scope readings can be deceptive.
Also, since the noise has differing frequency content, the perception of louder will be dependant on the bandwidth and freq response of the sound source you use to listen
@@DaveRat good points, I hadn't fully thought about that, I was listening through headphones and would have hoped it to be reasonably representative, so interesting to see that I hear it a little differently to you!
@@DaveRat PS, you're an absolute hero in my house, your videos are absolutely fantastic, and the way you show very complex systems/concepts simply is truly magnificent!
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It's true what you say Dave with regards to making crappy gear sound great. On Drumeo, Jarred takes literally a toy drum kit and puts some half decent skins on and "hey presto" ...it came up pretty good. With regards to the Q series console, that buzzing could be earthing differential between maybe the logic board and the AD-DA converters... maybe? 🤷🏻♂️Maybe some phantom voltage leakage being drawn from the input despite it being off? Dunno but it's great how you find these quirks regarding things to watch out for. I'm still happy with my little Midas M32 best bang for buck me thinks. 😉
Cool cool. Yeah, not gonna dive into why as much as look for Gremlins.
Hi thanks for sharing knowledge!
Please tell why xenyx q1204 makes noise when fader is fully upward
Because my xenyx x1204usb is creating same noise when volume fader is full or when gain is full, and this happens without putting any input in channels, I'm only connecting output to speaker any when putting fader and gain to full it makes same noise as you are using for this video
I'm not sound guy so I've no idea why it makes...
Is there any issue with my analog mixer or does they create this noise when volume fader or gain is full?
All consoles do that and adding lots of gain to a channel with no input will have even more noise than when there is an input load.
The Xenyx is not a very quiet mixer, it's is more quiet than an x32 or qu16 though, for the same gain
@@DaveRat ohh thanks alot for replying and helping out.
Finally I don't have to throw it.
Thanks again!
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Would love to see the same experiment with the SQ6 instead
www.prosoundtraining.com/digital-mixer-study/
Thanks Dave
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Great video. 😃👍♥️
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Contacted Allen and Heath for...feedback?
Hey Dave, Thanks for all your interesting and informative experiments! I've never used the X32, but have used a Qu-32, so I'm not commenting on the 'which desk is better'. I'm not up on electronics, but I see info from a reputable place online that mic level is up to around 0.001volt, and line level is up to 1.00volt. OK, there might be some gear that pushes the boundaries a bit, but is the 9.3volts in the range of concern for normal mics and electronic musical instruments? Genuine question.
Many X32 and Qu-series users run Ethernet stageboxes. In A&H gear, I understand the stagebox has different preamps to those in the desk. Would be interesting to see if the same issue persists with them?
I am using peak to peak voltages as they are easier to read on the scope.
Usually people refer to rms voltage.
9.3 p to p is about 3.3 v rms and music typically has 3 to 1 to 10 to 1 peaks. So a 1 volt rms signal will often have a peaks well exceeding 3.3 volts rms
Thanks @@DaveRat that puts it in perspective for me now. Two takeaways for me: Qu users should avoid crazy hot input signals; and maybe we shouldn't be too quick to overlook good old analogue :-)
The big issue for me was the QU was distorting even when the clip light was not lighting.
And the test inputs are not that hot, they are of a level you would expect from an audio playback device with a +4 output, which is common
@@DaveRat Certainly one to look out for. Think the only time I've heard clipping on the Qu was when I had made a mess of on-board compressor settings on a vocal channel. Audible clipping but no clip light. Thought the vocalist was too close & loud on the mic, but then I checked the DAW recording (signal tapped-off directly after the pre-amp), and it was clean. Guess it depends where the clip light is positioned in the circuit, but it's another one to look out for.
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What do you use for noise generation
Sound Bullet for pink
Please make a comparison on Presonus STUDIOLIVE 32s and Midas M32 console
Hmmm, don't have a presonus but if one shows up somehow, will look into testing
Woah very interesting! Would be curious to see if the SQ is the same.
I maybe someone that has one can test and post
@@DaveRat Please do, since the QU series is really old tech and comes from the dark ages at A&H. Their new stuff is super good though. And if possible, please also add a DX168, so we can have the dLive preamps in the mix as well (which would be the quivalent to the Midas Pro Preamps).
Will ponder that. But more importantly, rather than me testing it for you and others, I am highlighting issues and using relatively inexpensive test gear and simple methods to do so such that you and others are able to do the tests you desire on gear of interest.
My videos are to teach you how to test more than for you to observe the tests
Thanks again
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thanks
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amamamazing!!!
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Please check out an SQ series Allen Heath your not comparing apples to apples with the Qu being a considerably less expensive console than x32.
That said I love your videos!
Hmmm. Qu16 2199, X32 2499. Sq5 3899
Seems in the same price realm with the more than the sq.
And thank you. May look at an sq at some point
Well it was lol. There have been two price increases since I purchased an SQ and I believe the x32 dropped since the Wing came out. Having owned multiple Behringer, Yahama and Allen Heath consoles the SQ has been my favorite so far.
Cool cool, hope to check one out at some point
Thank you a lot for this (another) great and super interesting video.
Very strange and impressive how the A&H reacts to higher voltages.
Do you by chance have any experience with Presonus recent mixers (series III and III S) ?
I'm quite interested by their stuff but I never see any Presonus gear in venues or festivals
I do not
Can you do the SQ next? :)
CL1 Yamaha is next
@@DaveRat Think you'll get around to the SQ at some point?
Possibly, but I'd rather see people use the simple tests I have done in the videos and test their own boards and report back what they find
@@DaveRat I hear ya. Maybe I have some homework to do!
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I prefer the Midas M32 over the Behringer X32...better pre amps
So do I, as I own one, but, not the point of the video. It's obvious the M32 would perform better, but the X32 is more popular due to the price point. I prefer my M32 to the X32 any day of the week, but I'll rock the shit out of whatever board is in front of me to the best of my ability.
@@rickdagrexican7351 The sound is my first priority, but after that things like look, feel, workflow, and build quality factor into it. I'll take the QU-16 over the X32 any day of the week even though the M32 supersedes both of them and isn't out of the same price range...whats a couple hundred more when ur spending thousands?
Interesting. All the tests I did seem to show that the "better" in "better preamps" means lower noise.
And low noise is good but the actual sound appears to be very close to identical.
@@DaveRat it does appear to be apples to apples thank you for the demo and the response!
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At first glance, the X32 has a very noisy analog output buffer.
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