Aux Fed Subwoofers Are Better - Because of How Mics Work
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- Опубліковано 25 чер 2024
- I explain and demo the issues with subwoofers connected to the left right outputs and show why controlling what inputs are sent to the subs is preferable, due to microphone limitations.
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00:00 Introduction
01:12 Mics are flawed
03:20 Diaphragm mass
06:25 Mics add unrealistic low end
07:56 Demo of subs aux vs subs to L/R
11:31 Dont send inputs to subs that dont need subs
13:18 Outro
I gave up trying to explain this to LR hacks years ago.. It's a lost cause. Thanks for making a video about it that they can't argue with. You're doing a great thing here Dave. Most, and I mean MOST, sound guys would rather belittle someone for not knowing what you feely share, than actually help each other out. You may have gotten your chops years ago, but you continue earn your respect every day.
Thank you so much Bob! Yeah I remember years ago we would rent gear to some vans playing a metal club and they were engineers that were taping over there board channels so you couldn't see their signature snare sound EQ and they would go back and dress up in hairspray their hair before the show.
And I thought to myself this is exactly the opposite of anything I ever want to be
Hearing my favorite tracks in atmos pulled me from depression, hearing that song live pulled me from addiction. Music and audio can move you from your worst to your best, as long as you can hear the emotions. I totally get the the vibe of this guy. Love to all! Please keep posting my brother.
Thank you and awesome comment
Totally hear and have experienced what you are saying … at least on a similar level.
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Hope you're still doing well, brother (or sister). It's a classic cliche, but one day at at time, and don't let the bad days make you think they'll never be good days.
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I have been doing live sound for 2 years and this is how I was taught . Subs on a Aux. That's my personal favorite how to set up the subs. Gives me more control.
This is so fun for me to watch. I love skills and how they are taken seriously. I’ve always wanted to make music, but have always wanted to start at the source. It’s very enjoyable watching you give your art to the works. Thank you good sir
These are the types of videos that I enjoy most: often overlooked but simple techniques that reinforce common sense.
Keep ‘em coming, your Ratness!
Awesome and thank you!
Seeing Dave get excited playing from the tape hit home for me. I remember the first time I got trained on a tape machine and got to run the tape remote as an assistant engineer at Evergreen Studios and its the same reaction. Its just cool, makes you smile watching it work and do its thing.
Yeah, it was fun and also skittish getting those old machines to work
I love having a separate send to Subs! Consoles like M32/X32 have a mono/center feed which i use to feed subs. The awesome advantage of using is unlike an aux send, you can set m/c to follow LR Level so you can bring the whole mix down without altering the relative balance between Mains & Subs.
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A work around would be to set the aux master to the same level as your main fader, and if you need to change the main just match the aux. But agreed; boards that have a mono or center bus is pretty handy
I sometimes use a matrix for a second set of speakers and put L/R and the matrix in a dca group. That way you can control all speakers with one fader if necessary .. and are still able to control the balance with the matrix or/and L/R fader. Works with M/C, too of course.
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Adds an independant layer of insert, eq and compression, too (at least on the x/m32), which is pretty handy.
Dave...thanks so much for all the great content you create. I was so inspired by this video of yours, that I ran my subs on an aux (for the first time) this last weekend for 2 shows. I have to tell you that the results were MAGICAL. The system was so clear and punchy and I didnt have to push it hard at all. The bands I ran sound for were very pleasantly surprised. I got lots of compliments on the sound too from audience members. I am never going back to full range stereo again. Your demo of what was leaking into my subs proved your point without any doubt. I was confident that doing things this way was going to work. Keep giving us your confident opinions and more education.
Thank you you just made my day!
I love that you did this demo with an ADAT... OLD SKOOL! Awesome as always Dave. Great explanations!
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I’ve been obsessing over this topic for months now!! I love the concept of the LR going everywhere and using EQ to determine what goes to what. I started doing virtual sound checks at home with two mains and a sub, I noticed that a bunch of vocals, guitars, etc were going to my subs even though the vocals are HP at 170hz!!! And subs LP at around 100hz. It just didn’t make sense to me or I kept thinking I was doing something wrong. Lol
Thank you so much.
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@@DaveRat @Rene Why is this happening though? Why are frequencies above the crossover getting through? Is it because the slope of the crossover is too gradual and some higher frequencies get reduced but not muted? If so, should the sub be calibrated differently?
A high pass is a filter. That filter has a slope quite often 12 DB per octave.
If you sent a high pass at 200 and the slope is 12 dB per octave, one octave down is 100 HZ so the sound will be 12 DB down at 100 Hertz at 50 HZ it will be 24 DB down.
You can get high passes with higher slopes but the higher the slope the more they impact other things like phase shift and ringing
If you don't want something to go there don't send it there if you want most of it not to go there but some of it to still get through then use a filter
When I switched over my sub to a bus control it made a HUGE difference. I send only kick, floor tom, bass, bass side piano mic, and sometimes guitar if it's a lone acoustic. This is spot on! Cut the crud and let that sub sing freely! It's the ultimate form of subtractive EQ'ing. Your listeners will thank you, people with hearing aids won't need assistive listening devices in most cases, this is an indoor set up, and the bass will sit soooo nicely in the mix.
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Equally applicable to mixing for recordings. It's the same reason to high-pass tracks that shouldn't contribute to sub (subjective choice, of course). I find your videos make sense immediately, though I may not have ever thought about the live use case before. This is another very helpful video. Thank you!
Awesome and thank you
I love the sound of ADATs rewinding! That brings back memories. I had three XT20's. I still have one for archives.
I agree that maintaining the crossover point is important. Always did aux fed but noticed when well mixed the send would always be close to each other. The current system I work with is stereo to all but ive been considering ways to isolate the subs from signal I dont want in there. Working on a Yamaha right now so I think were going to put the subs on the mono buss. Thanks for all your encouraging videos. Im glad to know im not the only one considering all these ideas you go over.
Often people will respect your opinion over mine but i take it if it means implementing the improvements and opening the eyes of others.
Your company did an event for us at Anaheim last year the crew was awsome, thanks.
This is what we are using in Dolby Atmos; sending channel low end to the SUB/LFE from each individual channel, object or bed.
You’re hypotheses really make’s sense.
I will now consider some sort of wind protection, in certain areas of microphone placement, and give you’re idea a go.
Thank’s really useful.
Love that
I have mixed with aux fed subs for many years, I just love the control it gives the engineer and as you mention you only send info to the subs that you want to be reproduced in them.
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For a very long time, I avoided the ‘sub on aux’ method. My main motive probably arose from the fact I am always multitracking every single show I mix and make the effort to filter all my stems accordingly. It’s only recently I see the flaw in my reasoning and Dave helped a lot with it.
When simultaneously mixing and tracking, the responsibilities add up to a level that can be a risky undertaking if setup time is short. A ‘sub on aux’ directly addresses both issues in an efficiency and most important, sonic improvement. In a console with 70-80 mix channels, barely a handful need to contribute to the subwoofer. Post-aux feed the few and mute-aux the remainder and you have beaten several major issues in one smooth move. If the console allows, flip that aux’s master to a fader for inventive FX.
Super cool and great perspective
Absolutely!!! I've been using aux fed subs for about three years or so now and what a major improvement in FOH sound it makes!!! Everything is cleaner and clearer and we never have vocal mics feeding back through the subs!!!
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Nice video Dave! I remember asking you this question because of seeing Pooch and Rabold saying they DON’T do subs on an Aux. I found it fascinating because since I’ve been learning the craft EVERY engineer I learned from and every venue I go to has the subs on an Aux option. Great job explaining why you want it!
Yes, Steve I remember and you are the inspiration for the vid.
Yeah, don't need subs on a send but unless you need subs on all inputs you will add high pass on inputs that may not need it and will get unwanted energy sent to the subs which is usually time lagged bass bleed, handling noise, wind noise and vibrations.
@@DaveRat Very cool! There is one venue I'm in often that is full range and it' such a different animal. I have to be WAY more liberal with high pass filters. In a weird way I'm glad I'm forced to mix full range at this club so I have an idea of how to handle it if I run into it in the future aka more aggressive with the high pass on all instruments. Otherwise the low end swallows everything. Hopefully I can jump on a zoom soon!
There is a subs on an aux emulation option as well
Feels good hearing my favorite engineer reinforce a practice I've been doing all along. Can't imagine not having it separated out, or being able to set higher or lower levels for certain instruments in the sub mix.
This is perhaps the best demonstration of why bass management is critical that I have ever seen. Trying to explain/convince others that are stubborn (and we all know at least one), I'll send them this link as well!
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most desks don't have/most people don't use filters anywhere near sharp enough to cut sub frequencies to -inf with the filter set anywhere that won't also impact how it sounds on the tops, and using filters that sharp has its own phase consequences.
There's a reason cinema has always done it the dedicated send way.
Agreed and even with identical sharp filters to the sub crossover filters, filters let some sound though, a send can prevent any sound from getting through
Big 👍 for Aux fed subs. Only Kick, Floor Tom’s and Bass is sent. Very helpful in challenging rooms. Great content. Thanks!
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I'm a newbie compared to many here, but I love this concept. Dave, I very much appreciate in your videos that you present the reasoning for such techniques and then demonstrate using real world audio. It really helps someone like me to make changes that actually impact sound in a positive way. I'm very grateful for your efforts to produce this channel.
Thank you Kurt, that means a lot to me and makes doing this worthwhile
Then make sure to listen to other sources. There are many reasons why Subs on Aux are not a good idea. Especially if you are not 100% sure what you are doing here. Michael Curtis has a good video on it. Pooch van Druten (Iron Maiden, Linkin Park, Justin Bieber) doesn't do it (just an example). Subs on Aux is a possibility. But you should really check if it is worth the extra effort, and if you cannot get a simular result with proper processing ( and not put the HPF on a vocal mic on 90 hz).
Especially with PA systems nowaday going down to 35-50hz (l'acoustics K1: 35hz, d&b GSL: 45hz Meyer Panther: 55hz) it is imo a better idea to handle all these things with proper PA setup and highpass filters. It's not only Bass and Drums down there. Metal Guitars are often around 60hz, clearly in the subbass range. Male bassist vocals also have frequencies around 85hz. Not using subs on aux does prevent you from falling into these pitfalls.
Make a post preamp recording of the next show you do and sit down and check your channels and how a HPF affects it and where you have to set it to get rid of dirt in the bass frequencies.
There are certainly many ways to accomplish similar outcomes. All of the things that you mention reflect our current setup. Now I know of an alternative approach that I had not previously considered. Options are good 😊
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I don't buy the argument that since a pa goes down low, one should send instruments that do not generate sub frequencies but the mics do pick up low end crap, to the subs.
What kind of logic is that?
Just think of it in reverse. "Does this input need subs? No? Ok, then why send to subs?"
As far as being in control of your mix and not ruining the recording, of course, avoid that regardless of how your subs are sent.
You don't need subs on a separate send to get a good mix but also, not sending excess unwanted crap to to the subs will always sound better than sending crap to the subs.
The question is whether the difference in any situation is audible or not.
And that is fairly easy to test. Which I highly recommend.
Don't believe me or anyone, test it!
With subs on L and R, dial up your mix, high passes and all that, then mute the mains, then mute all the inputs you do want in the subs and then, whatever the subs are now doing is the excess. Look at that signal in Smaart, go listen to the subs, see if they are bouncing around, maybe they are, maybe they are not, and then decide, "is my mix better with this noise added, does it matter? or should I setup my mix so it can be removed?"
And remember to enjoy learning and avoid dogma
Dave, you're one of kind in my world!
I've never heard anyone consider the topics of which you speak!
And not only do you talk about the theory but you already have run the tests to prove or disprove what you propose at the start as a "what if theory"!
I always learn something from your videos even on topics of which I am (or believed I was 😞) somewhat knowledgeable!
How absolutely BLESSED the people in your life are to have you around on a regular basis!
They probably don't even realize it!
Well, not your daughter. She seems to get it!
Thanks for this lesson!
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Thank you! And I do have wonderful people in my life and appreciate the positive comments!!!
Great to hear you say this. I've been an advocate of aux fed subs for a very long time.
I work in corporate rather than live music but from time to time the PA will have subs in it and often times it's set up by someone else and I come in and mix the event. I often find they've either sent everything to the subs or in the case of d&b PA they've set things up in mix/top sub configuration letting the amp's crossover handle the split.
I only need my playback machines and background music to go to the subs but they've routed everything: top table mics, lectern mics, lapel mics, hand helds, everything. So I unpick their rig and route things my way with only the things with desired low end information to the subs.
Even for the mains I tend to roll off a lot of the low end in most speech mics to minimise unwanted noise (and try not to remove the colour of the presenter's voice).
I suspect this old school purist matrix/mono sub routing ideology is also why so many live music engineers have really flabby sounding subs rather than tight and punchy ones!
That is another great example of why subs need to be seperate
With mix/top sub with d&b you can still set the input source of the sub outputs to a different input.
You just need to know how to navigate the amp.
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A practice I live by. Learned from you waaaay back. Thanks!
Awesome Perry!
I’ve been running sound for live bands and dj gigs for 20 plus years. I don’t call myself an engineer by any means. I’ve always set up my and everyone else’s rigs with the subs on a separate send where I at least had control of them independently. Only recently discovered I could aux send the signal a few years ago. When u clip all the extra garbage out the sun send it cleans them up tremendously I was so happy when I got that low mud I couldn’t find before out of my mixes. Most people didn’t notice but I could hear it. The new digital stuff out makes life a whole ton easier. The people buying a new Xr18 don’t really comprehend the processing power they jus purchased. I learn something every time I power on. Great video. And demonstrating the output. Fantastic
Wow, this was illuminating. I haven't been able to comment or browse vids for awhile (life's been busy), but this was an eye opener. I always assumed that high pass filters generally did a good enough job that you could mix into L&R only, but I never realized how much remains down there to be heard in subs! Gotta consider changes at the church ☺️ Thanks Dave as always! Hope I can sit in on a members Zoom soon!
Cool cool Efrain and see ya soon zoom
Not much remains. DId you see how much further up he had to push the fader to get it audible?
That is a 3" speaker. Even the slightest amount of low end garbage is quite audible on a large sub system.
Would you buy a sound system with 10% distortion? Do you think you can hear 10% distortion added to you mix?
If the cumulative sub energy crap sent to your subs is 20db down, that would be the equivalent of 10% distortion.
But yeah, it's not the end of the world and distortion is hard to hear at lower freqs. And subs on an aux is not needed for a great mix and also, the great mix will be a bit greater with the garbage removed.
I think you have a great point but a bit too one sided. The more lows handled by the subs, the more headroom and clarity in the mains is too be considered as well. Depends on cabinet sizes, coverage etc... A lot to consider.
I will do more on this and show what sound filters let through that seperate sends prevent.
A high pass reduces unwanted lows and reduces lows sent to subs. And cleans up a mix
A separate subs send eliminates unwanted lows sent to the subs and cleans the mix up even more
Thanks for the heads up! I hope I get to hear one of your live mixes soon!
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An outstanding presentation, Dave. Evidence and all, you sold the idea brilliantly.
Thank you Peter!
Oh man. It's SO cool to see these videos for me! I have been fascinated by sound gear since I was like 10. I am now 53, and my health crashed 5 years ago, so I am up on blocks. I got the work I could, and am a lqualified mechanic, and engine rebuilding specialist, or at least I was. I have however been reading and larning all I can about sound, and you never know, someday I may be able to use it! I also am training on electric fundementals with one of the most experienced engineers in Canada, who has retired, but he kept a shop, and we are buddies. HUGE opportunity. Anyhow, thanks for the videos!
So cool and never stop with curiosity and new adventures!!
Good session, Dave. Very informative as always! I was getting nostalgic when you mentioned the ADATs!
👍👍👍, I need one more and yes having them working as a blast from the past
I know this is an older video, but I wanted to say thanks for the content on your channel. It’s nice to get some real-world data/testing to ‘prove’ the things we know are the right thing to do.
I just picked up one of your CAT5E cables, by the way. Glad I found you here and that it led to some good equipment purchases!😂
Awesome and thank you TheDude!!
As always, true passion for the thing called sound/audio!
Fun!
I think the same, most people ignore this, some think 'ok why not'... I like it when an Aux Bus is set to post fader, you just put the stuff you want/need the subs, and thats it. Easy and clean. Plus you have additional processing on most aux buses so you can further shape the low end.
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I inadvertently replicated your demo. I was installing a replacement mixer and cleaning up a few things in the process. When I tested one of my mics to make sure that sound was properly passing through the new mixer, I was hearing only low frequency distorted sound. My initial response was I didn't know what I was doing or there was something wrong with the new mixer.
It turned out that the speaker terminals had pulled out of the mains amplifier while I was moving one of the racks. This left me with only the sub connected. It didn't make sense to me that I was getting such distorted low sound, as my voice should not have had any impact on those frequencies.
Your point about microphones imperfect reproduction of sound became crystal clear. Without your video, I would probably have never understood the dynamics of this situation.
Perfect
You have a great way of explaining complex concepts regarding audio as we hear it and audio as technology that attempts to simulate audio as we hear it. The major point I get is that much of that audio is felt and not necessarily heard, but microphones can’t adequately compensate for this. In order to simulate the experience a cleaner and more effective mix you must exaggerate frequencies with audio that is meant for the output they are given.
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The moment I realized many years ago about running subs on an aux my world changed for the better. I often use subs on a matrix to control subs in some situations but my favorite setup now is how the X32/M32 new firmware handles subs on the mono send... Each channel has a sub level that sends to the mono as a sub out like an aux send but there is also an on/off button. So I can really dial in low end the way I want. Sub or no sub or a set level and I can pass filter along with that. And as someone else also mentioned that mono sub send follows the main L/R level with mute. I love it. I do a ton of conference and AV events now and that sub on and off on each channel is a game changer especially when you have to do video playback... So many people that edit video these days leave a ton of low end garbage on voice so I pass filter and turn subs off. Or video conferencing returns sound terrible with any low end let alone subs😉
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Finally tried it last Weekend, Gotta say, truly liked it! Thank you!
Awesome that makes my day!
Damn, you make me want to reconfigure my system for aux fed subs. Been running full range for simplicity sake, but you make a damn convincing point, and any other engineers probably just need a note ahead of time and they'll be ok with it
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I'm a mobile DJ (not a sound engineer) and I should not find this nearly as exciting as I do. Thank goodness there were already thousands of viewers before me to make me feel better. The microphone explanation was priceless and overall eye opening. Thank you.
Awesome and I hope at some point artists release music with left, right, subs and more. That said, as a DJ, rather than dum lows for tracks that you want to lose lows, having the ability to not send to subs may be interesting
This has the added benefit of not needing as big of a sub amp if your only reproducing the desired content.
Yes, a 3db drop in energy sent to the subs would mean using 1/2 the power
@Dave Rat, you're f-king brilliant. Maybe this is a measure of me as a live sound engineer but you always come at me with a problem I never knew I had and change my whole approach. Top! Ta
Thank you so much!
That little sub is great for showing you visually how much energy is there. That wasted energy can mean the difference between enough headroom and no headroom. I do some small, low budget events where the PA is often undersized. I find subs on a separate send makes a difference not only to the quality of the mix, but also the available headroom of the subs.
Agreed
Dave, you are the best. I love your videos and I learn a lot watching them. thank you for your time and effort.
So cool thank you!
Gracias amigo Dave, definitely the truth for me as I do experienced my self and the result is a cleaner sound on the overall, thanks again for your contributions. Saludos from Michoacán México
¡Buenos! And thank you David
Great content Dave! I'm sending this to our soundguy!
Awesome
Wow! So simple... but I never thought of that... Thanks for another great advice-video, Dave! 🙂
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Having done live sound for ten years and then 35 years of designing installed systems, I specify that vocal mics (mostly spoken word) are not part of the matrix to subs. It makes the voice/s more clear and articulate whilst preventing feedback into subs. Most of these systems have audio DSPs under system wide touchscreen control, so it is no big deal to program the DSP accordingly and lock them to stop people messing with them!
Love your sessions Dave - you are an original thinker with masses of experience to back you up. Please keep 'em coming.
Awesome thank you Peter!
Sometimes I found the best for spoken voice is to feed a lot into the subs and then eq and sculpt your vocals off of that
Backwards approach maybe but it gives your vocals more power and punch
Hmmm, with a subwoofer being a speaker that reproduces sound below what the woofer reproduces, sub woofer frequencies, we typically you're talking about frequencies from 20 Hz to 60 or 80 Hz.
So these frequencies are booms and pops and rumbles that you feel in your gut and tend to be very distracting from actually listening to what someone is saying as a true subwoofer only reproduces frequencies below the actual human voice.
I can understand using subwoofers as an effect on a vocal but you would have to be quite careful because even the slightest breath or touch of the mic would shake the room with a two subwoofer system.
I get the feeling you are talking more about low frequency drivers and warming up the vocal then talking about actual subwoofers
Thanks again Dave, for getting more live engineers in on the ways to make systems shine and flow! It benefits us all, engineers and listeners, to produce and enjoy a more sonically pleasing experience. Cheers!
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I've never liked powered speakers linked to powered subs when mixing a live band. I've always found the mix so muddy. I used to think that I was doing something so wrong by using a sub on an aux send haha. Other than the mix being cleaner, I'd like to think that the subs would be working more efficiently not having to worry about the "junk" getting in.🤷♂
I love your videos so much. My best subscription on youtube. Thanks for sharing your knowledge with us good sir🤙
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So orderly, but oh so musical… thank you for sharing this VALUABLE knowledge and thought process!
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Hi there , Dave I've always used aux for subs just because this reason ! Just thanking you for all these great content! I love to learn, and you are one of my best teacher since my math s teacher from the first grade! I wish I to know you from the very begging of my career hahah! Thanks for all and when you come to Rio , just let me know. Would be a great pleasure to shake your hand! thank you for all! and sorry for my bad English.
Very cool and great to meet you. I've been to Rio several times and it was wonderful!
So from now on, my colander strainer will always be known as a condenser strainer! Can't unsee that, great visual demo. Great video...
Awesome and thank you!!
Another amazing video Dave! Still waiting for that monitor/room ringing put video 💪❤️
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The old Yamaha Sound Reinforcement Handbook recommended this 30 years ago (for the same reasons) and I still do it. The laws of physics do not change. The problem is that most live engineers have never read a book. Every engineer should at least own the Yamaha book and the JBL Audio Engineering for Sound Reinforcement.
Interesting I will take a look when I get a chance.
Nice vid. I do more corporate stuff than bands these days, but I started getting into the habit of only sending video playback and pre-recorded music content to the subs on an aux mono send (post-fader), and then not sending any microphones to the sub. I worked with a guy who was sending his entire L/R mix to the sub on a matrix and we solo'd out the sub and you heard faint rumblings from open mics. I'm glad to see I'm not the only one who thought that method was weird, hah. Also, low passing the sub to taste and adding some fairly intense compression can help really make the sub sit under your mains.
Agreed
So smart. Love your channel Dave! Keep doing what you’re doing brother 😎
Awesome and thank you Noel!
This is one of the best themes in my opinion, and very underrated for some folks.
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Great topic. I have done some installations where sound engineers insisted of having subs tied to LR output. I tried to negotiate that it is not right but no luck :)
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This was really helpful. Thanks for making this!
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Love the idea. That really has to make the low end really clean and clear and would argue that if you could employ a crossover on those low frequency instrument channels, you could eliminate phase problems between subs and mains.
That would just be a glofied high pass and filter lows but not prevent the instrument from being sent to the subs
Also, issues with sub crossover perfection are over rated.
Any issues only impact a very narrow band of frequencies at the x-over point.
Plus, unless your subs and tops are physically extremely close together, an audience member moving closer to subs and father from tops or vise a versa, totally screws the crossover summation anyway.
So you have the ability to clean up lows and possible slight impact crossover issues that are already there, or you just have the crossover issues anyway
Putting sub/main on phase is very important (and yes its never perfect wich is why you average it with several mics) but using aux for sub doesnt prevent that.
Just set it up with the console setup you will use and make a dca for main+sub in case you have to change your overall signal.
Thanks Dave. I always learn something interesting from your videos.
Cool cool Joel!
@@DaveRat AND, I've been using aux fed subs for years and love it. Have no intention of changing regardless of what the naysayers might claim.
It just works for me.
The beauty of the naysayers is that they voluntarily choose to give those of us who desire more control an advantage to sound better than they do
Years ago I attended a great seminar by Buford Jones for Meyer Sound, where he addressed sub-woofer levels. So many techs just push the subs up to full power meaning there's basically a huge level boost at the sub-woofer frequencies. He advocated a balanced system, and to prove the point played some gig 2-track board tapes through a system, which not only sounded amazing (I think it was Jackson Browne), but had a completely smooth and balanced low end.
Take time to get a balanced system, then use a separate sub-woofer feed, and you'll be a long way to getting a clean and musical low end!
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Love the way you explained. Thanks a lot
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This makes complete sense to me, I am picking up what you are putting down my friends. Great explanation and topic. Cool Cool! :)
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Wow, something I never really considered! Great explanations!
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Very insightful! Great explanation on this topic!!
I have been doing aux fed subs for many years....since way before digital consoles etc. I started when I acquired 4 EAW FR 253 cabs for FOH along with 8 single 18 JBL cabs. I experimented by running the EAWs full range in a LR combination and ran the subs in mono on an extra aux send, it was like the sky opened up and the sun came shining through....i only used an external crossover on the subs and a separate EQ as well......i could dial in what I wanted through the subs, things like cymbals, drum overheads vocal mics etc could all be dialed in much tighter and I wasnt using all of the energy sent to the subs that was being wasted on things that just werent generating those frequencies. It cleaned up the mix tremendously, of course I could also use high pass filters to keep those unwanted frequencies out of the FR cabinets as well. I still to this day swear by this method, it has worked wonderfully for me.
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Thanks for the explanation, I am running the sound for a student council party at my college and we have a weird collection of random technology. Feeding a Macbook into a Yamaha MG16XU which then outputs into a Yamaha PX10 to power the 2 passive Dynacord D15-3. That is where I struggled to find a good solution, cause the Sub we have is an active RCF sub 905-as ii. At first I didn't know what to do, cause usually we get active speakers with passthrough, but now I am excited to run the sub over the Aux send, and possibly in the future with other setups as well.
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Great Points. Im going to look in to this deeper
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Very much appreciate this information, the demonstration was very helpful too
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never thought of that. basically cleaning up the low end… lots of mud off… thanks for this
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I've been a sound guy since 1989...and also played in bands early on. I remember having this debate in the late 80s...and we (the band) agreed that subs on an aux would be preferable.
We had a 24 channel analog console, with 6 auxes, and 4 sub groups. And we had one stereo two-way crossover. We used that to send lows to the subs, and higs to full range, passively crossed over tops...the classic quasi-three-way system that was common in those days.
So the dilemma became how to create an additional send for the subs, and purchasing an additional crossover, so we could separate the subs.
We ended up buying a bigger console and an additional crossover, just to achieve subs on an aux. The band eventually broke up, and I ended up owning the system...which I began renting out. At the level I was at (small time level), it was quite the selling point to be able to do subs on an aux.
So cool
Mixing the Tasmanian Symphony Orchestra back in the day I would have 8xdouble 18” boxes just for Cocert bass drum, principle double bass and tube via an aux send for live outdoor sound gigs… love this concept and teach it to others 🤓❤️
I learned subs on aux near the beginning. The video is actually pretty relevant to me because I hold Mr. Rat's opinion in high regard, but also somewhat recently had made the switch to LR after a diatribe from a very senior, touring engineer advocating LR and basically telling me that Aux Fed Subs are a flawed way to do things.
His reasoning was, as I understood it and recall: Take the kick drum. You make a certain EQ for the kick drum and send a healthy amount to sub aux. In further processing the kick channel you decide to send more or less of it to the sub aux. In doing so, according to that engineer (or how I understood him), realistically that will change how that EQ or processing is behaving on the channel. Sending more kick to the aux sub creates an effect where the processing for the channel is no longer predictable, as the amount of kick in the sub is increasing and potentially blurring the phase(?). Just by virtue of something being louder or quieter there's a natural/psychoacoustic (fletcher-munson-type) EQ curve thing going on. So for only the crossed-over low end to be raising in volume against the LR image of the same channel.. phasing and predictability of processing suffers. Something like that.
And just one gripe I have with the video is in the HPF demonstration portion, the HPF demonstrated is much lower than engineer are actually using when they use LR, no? Vocals will end up going to something like 150.. depending on the slope as well. And for a high hat which is by the drums and bound to pick up low end, a 90hz HPF is pretty unrealistic. That would go somewhere to at least 300hz and have no chance of being the subs I'd assume.
I definitely digress, I'm not an authority on the subject. It was my deference to that one engineer that made me try to understand exactly why he was so adamant about the concept. But of course, at the end of the day, we use our ears - and I've personally never been inconvenienced by the concepts above when using aux fed subs. So it really does come down to a bit of a "purist" contention. But if anybody more learned could tell me if there's some truth to the concepts, I'd be interested to know.
I used 90 Hz because most true subs crossover at 80Hz. So I could show that a high pass at 90 let's loads of energy even when the subs only go up to 80.
Setting super high high pass filters does reduce energy to subs but also tends to sacrifice warmth and sound quality.
With subs on an aux, those things are seperate. You set the high pass for best sound, not to keep energy out of the subs. You send to the subs for best sound, not just send everything and try and high pass out the excess
Very interesting explanation,thanks Dave
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Dave, love your content! Thank you for sharing your knowledge! Your examples are so clear and complete - I just love watching and sharing your videos!
I've heard all the arguments for or against Aux-Fed subs - It IS the industry standard (I see more riders specifying that subs MUST be on an AUX) for a reason. I don't know why anyone would prefer to send all the material into a bus, to cut it down in the console, processing or sub itself (for self-crossed-over powered units). My theory has always been that anything that isn't turned into sound is turned into heat - whether that is just processing power sucked-up by having to trim out all the unwanted frequencies before the output, or actual physical heat at the power amp input or turning the signal into watts that won't get reproduced by the sub speaker anyway, or at the speaker getting a signal that it can't reproduce - there's just no reason to do any of that when you send just the sub frequencies out of an aux or bus. Basically, if my subs catch on fire I want it to be because we were cranking SOOO MUCH bass, and not because the system was setup to generate undue signal/heat...
I've found that too many (young?!) sound guys want the subs ALL UP ALL THE TIME and getting them to mix the bass and kick to be full/present in the subs but not eating up the audience area with low frequencies is a real challenge. We all like a good, full, punchy, loud concert, but there are ways to get a good sound without just ripping the low end items 100% all the time! The first place I look/knob I reach for if a kick or bass isn't sitting in the mix is that sub aux, a gentle turn DOWN and a boost on the fader usually sets the world right again and instead of just turning any part UP, the instrument fits in its place in the mix and everyone is happy...
Yes
it's always reassuring when a video about audio mixing has a high pitched noise for the first 3 and a half minutes
Yeah, never been much of a video guy. More worrying is an audio guy doing video at all. The good part is ya take it or leave it if the info I am offering to a couch critic stranger is appreciated all good.
It's not like it's not like you paid to see a live show or anything
@@DaveRat that was only meant as some light japes. We've all missed bits like that in productions, from unfortunate personal experience I learn best from when stuff goes wrong. But still, it is pretty funny for content on audio tips to have audio issues 🤭
Regardless, thanks for the imparted knowledge. I've used sends for subs before, mainly as it's a cheeky way to create a combined mono of the mix, but it didn't occur to me to be selective with what was sent to it. Using sends is also a quick way to create a combined mono mix for recording onto old mono samplers like the Akai S950.
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Love your work. Great advice!
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Hey Dave,
Thanks for sharing so much of your knowledge, it's so interesting. I'm a Sound guy, but I work in a different field. It's fascinating to see how simular and how different things are for us all.
Much love and respect.
Still not sure about behringer though.... 🤔😉
Great to meet ya and I use the behringer to show that knowledge and skills don't require expensive gear
Good Stuff Dave! What made me switch to Aux Fed Subs was a scenario where I was mixing for a few comedians. One wanted house music and a few tracks for him to perform with and another playing guitar...etc.... so I used subs. My system was setup like I use it for rock shows. Magnitude Response has a tilt to it... strong in the low end... One comedian wouldn't keep the mic close so I started getting some low rumble. My RTA kept showing a frequency well below the high pass setting on the vocal mic. One guy and one mic... nothing else going on at the time. It hit me that I just need to make the switch to aux subs and I never looked back. The high pass filter isn't bullet proof on systems with a spectral tilt. That is what the problem is... but I don't like the sound of my system completely flat all the way from one end to the other. So on an Aux, it's impossible for a vocal to get into the sub unless you want it to. For others that don't have subs on an aux try this at your next gig: Shut your tops off and turn up the vocal mic and speak into it and listen to the subs. You will hear some rumblings in that sub even if your high pass is set pretty high... multiply that by all the mics and no wonder the low end is a mess. I love aux subs and 99% of the touring acts that came through our town venue wanted subs on an aux.
Yes and exactly and thank you
This man in a genius, thank you for sharing your knowledge!
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started using aux fed subs about 6 years ago and never looked back...just wished i discovered it sooner
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A great way of explaining the issue than showing it! Perfect
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I needed this...more than u know!
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Nice demonstration. I'm still using Aux feed sub. Cheers! 🥂
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Another great vid, thanks Dave!
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This discussion changes massively depending on WHERE the subs are.
- If they're flown together with the tops, so that the *entire* true-full-range signal comes from a single acoustic point, then you want to send a single true-full-range signal to that acoustic point. No separate control, because you'll only mess it up.
- If they're ground-stacked, separate from the tops, then there's no way to match the two sources for the entire audience, and so you have to wander the room during rehearsal or sound-check (virtual or live) and fudge it. Then continue to fudge it from the booth during the show. That fudging, of course, requires separate control.
Ground-stacked subs with flown tops are practically two separate PA's. Physically grouping all of the drivers in acoustically the same place is a single PA. Each PA requires its own separate control, but don't try to control elements of a single PA separately. Use the channel and group/master filters for that.
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Also, the demonstration of highpassing in this video is terrible. All at 90Hz is no thought at all, and probably wrong for every channel. Not a fair demo. This should be obvious when you consider that the crossover is simply a highpass for the tops and a matching lowpass for the subs. Period. You might think that the speakers' acoustic response adds to the crossover's response, which it does at the extremes, but if you rely on that happening, then it's a bad system design. Each driver should have enough extra range that the crossover filters do ALL of the work until the filters' response is down enough that the drivers' response is not audible anyway.
The *proper* way to use the channel highpasses is to listen to each one and set its HPF as high as you can get away with, without affecting its intended sound. Do this separately and independently for each channel, including the bass instruments. Bass sources will of course have the HPF set way low, because you want to keep their bottom end, but not completely disabled. Non-bass sources will have them much higher, with all of them right at the bottom end of what you actually want to keep from each one. Once you've done that, they will all be different. All the same is a blatant sign of naivete, laziness, or a VERY rare stroke of luck.
If you have an analog board that only has a button for a fixed HPF on or off, so that they *must* all be the same or not at all, then you might start to think like Dave does. I like mixing on analog myself, but that is one of its common limitations, especially for "affordable" small boards compared to today's pricing of digital consoles. Not all analog boards are like that though: some do have adjustable channel HPF's. If yours does, USE THEM!!!
Once you've set them all individually so that each one just barely allows everything that you want, continue to listen to it. If there's still too much rumble, and you must have a steeper rolloff, add another highpass in series. You probably won't need to though, considering the next section of this comment. But if you do, the X32 shown in the video can use each band of the 4-band channel EQ as an additional highpass or lowpass, at the expense of using that band for something else. (they're not fixed to being shelves and bells) And every submix on that board has a 6-band EQ that works the same way. No excuse to not send a muddy vocal to a true-full-range single PA. (the X32's output EQ's even have purpose-designed crossover filters)
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With all of that said, yes you will still hear *some* low-end of non-bass sources in the "subs" of a single true-full-range PA. That's only because the filters are not infinitely steep. But also consider that an unfiltered set of tops would have played the same thing. (if the PA is designed well, with enough extra range in each driver) You can get the same effect by adding a copy of the crossover filter to that source, but because *that* is not infinitely steep either, you'll still have *something* coming from the "subs". You can repeat that as many times as you like, cascading more and more highpasses (you'd probably need a DAW at this point), and still never get to zero.
Then consider how much of this pursuit is actually audible in the context of everything else. Probably none at all, just because of the actual levels involved. The residual after filtering the "stage mud" out of all the non-bass stuff, is so much softer than the actual bass stuff, that nobody's going to notice. Not even audiophiles. (audiophools might, but it has nothing to do with their ears) Even the residual from a single vocal by itself, is only noticeable to the people in the "mosh pit" next to the ground-stacked subs, who are there because they want their insides rearranged, and not because they want to understand the lyrics.
But like I said up top, if you have your subs in a separate place like that, then you want to control them separately for reasons that are NOT stated in this video. The reasons stated in the video are not relevant, given the middle section of this comment.
Hmmm, I understand the reluctance of people to cling to stereo and not progress the the complexity equivalent of home hifi 2.1 audio.
That said, high pass is helpful in reducing unwanted lows. Subs on a separate send is just the next natural step beyond high pass by not sending mics to speakers that reproduces sounds you don't want reproduced from those mics.
This applies regardless of sub placements
High passes help and seperate sub sends helps even further.
It's not that complex or scary but the benefits can be very audible in some applications and less so in others
Having subs on a send allows you to send everything to the subs or send somethings to them
Subs on LR only allows everything to the subs and is way more limiting.
Subs on a separate send from channels or groups or from matrix dialing up desired groups will allow everything that the more restricted subs on LR can do, plus the ability to improve things further.
Not having subs on a separate send is best for situations where the system does not have true subwoofers
Subwoofers being speakers operating at below the frequencies of a full range system
Having said that, I think that this other video from Dave ( ua-cam.com/video/wDcf184730E/v-deo.html ) is spot-on. And this one ( ua-cam.com/video/VLkQSSydXwk/v-deo.html ) is pretty good too.
If we were to play back a multitrack recording, still in multitrack, never mixed, to a set of near-omnidirectional, true-full-range, point sources, one for each instrument - or even several tracks per instrument, that go in different directions from that point in space - I think that's what Dave is going for.
What I'm going for, is for each point in space (and possibly direction from that point) to have a single electrical signal going to it, and whatever gadgets are responsible for that point in space, convert that single electrical signal into an air pressure that matches the electrical signal.
- If you send it bass, it produces bass.
- If you send it sibilance, it produces sibilance.
- Different location or direction? Different signal.
- Same location and direction? One signal.
Frequency isn't involved in that discussion at all, except for how to produce air pressure to match the electrical signal that each one is going to get.
I think that Dave and my overall goals are completely compatible. But this video in particular comes from the wrong reasons.
@@DaveRat I wrote my followup without having seen your response, and I think it's still accurate. I just want to clarify my use of the term "true-full-range" to mean honest 20Hz to 20kHz response, and not the 60Hz to 15kHz or so that most people call "full-range". I put the "true-" in front to distinguish that.
For pro audio 20 to 20kh is probably not realistic.
In fact, undesirable
Projecting 20 kilohertz hundreds of feet is prohibitive and having a system that will do so is a poor usage of resources.
Having a subwoofer reproduces 20 Hertz just creates more of a mess and there's not a lot of material usable down there from all but very few extreme artists.
Again a waste of resources having built subwoofers that go down to 23 Hertz have first hand knowledge of the importance of limiting the low-end below 28 Hertz or so.
Most full range systems for pro Audio would be 40 Hertz to 15K or so.
With most subwoofers operating in the 30 Hertz to 60 or 80 region I'll bring some overlap for rain system whether it's used or there's a distinct crossover between them
@@DaveRat Now that I can agree with! Every once in a while, you do get 20Hz or even 16Hz (pipe organ, sometimes, or a synth, and that fundamental is entirely felt, not heard), but for most things today, the lowest fundamental that it will ever get legitimately is likely to be a 5-string bass guitar at around 31Hz or so. (kick drum is roughly an octave higher) And if most of the audience is beyond their teenage years, they probably won't appreciate above 15k anyway. Maybe not even 10k.
For thinking it through though, I just want to make sure that the concept still works beyond the appreciable range. For a DIY PA for a small band, my actual design range does indeed bottom out at 30Hz, not 20.
This is such a sweet video to see during this “modern mixing revolution”. SO many engineers mix full range, and I feel like this video debunks a lot of their theories out there. I really appreciate your input here. Like you said, “it’s not about mixing subs on an aux, it’s about not sending everything to the subs.”
In general: how do you feel about flown subs? I work in a venue that has flown subs tied in with the Main Arrays. There are ground stacked subs on a separate drive line. The 2 zones of sub can be difficult for some engineers, but everything is in phase, and I personally really love the result. I feel like the best approach is to use the ground subs as supplement (on an aux.) Would love to hear your thoughts. Thanks!
Your comment about routing the aux to a bus at unity is the key thing many mess up. I've seen several chase their tails trying to get levels right because they don't consider this.
True and also, having an offset in sun level is not that big of a deal. It's the same thing that happens if someone walks closer to subs and farther from tops or visa versa
So informative ❤love your work
Awesome and thank you!
Fantastic info. Great video.
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Lovely video, great explanation to boot. Is that a Midas in the background?
H3000
Brilliant concept!
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This is GREAT!!!! Thanks Dave 🤙!
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I always heard of subs on an aux, but we subscribed to the idea of using the high pass to eliminate what you didn't want in the subs... Until we randomly blew a woofer. I then started paying attention to the sub amp meters when the kick and bass were NOT playing, and noticed that when a vocalist talked, or the guitar player struck a note, the meters lit up almost as much as when the kick and bass were playing. We immediately started running subs on an aux. Much cleaner mixes, and we haven't blown a speaker since!
Perfect! And yes. Imagine every mic needed to be on all the time in the main PA, yuck!
We can turn them in and off and up and down. Why would we not want the same control over the subwoofers?
@@DaveRat I completely understand and agree! We have been running subs on an aux now for 3 years. We will never go back!
Excellent video as always!
Awesome and thank you Harris!
Awesome topic. I’ve seen a lot of people say they use a Matrix to feed their subs and mains. Most of them send their entire LR to the sub matrix though and create their own crossover with HP and LP filters. I like your idea of using a group for all sub instruments and then sending that to a matrix. I feel that might be the best option. I never realized how much unwanted low end energy gets sent out.
8ve done setups live with the group send and compared and the difference was quite audible
They're most likely eyeballing the system integrator's job with a janky workaround. The system crossovers should be handled by proper speaker management systems or inside dsp amps. This way, the system integrator can tweak every delay and tuck phases into place for optimized spatial distribution and frequency response. You can still feed subs seperately in such a setup, which would be ideal for sound quality and flexibility. If you just want a stereo setup, send the main mix to the sub-group. If you don't want that, send individual instruments there as you please.
Agreed
@@DaveRat I agree, unfortunately some manufacturers are a little conservative with their parametes (L-Acoustics won't let you freely tweak he crossover freq for the subs to anything else than their set freq AFAIK) hence the need for a matrix. But agreed the "to-the-subs' groupe absolutely makes sense.
You don't really need to mess with it but yeah, I used to carry a crossover that I would put in the subwoofer out and have the option to low pass the subs further if desired
I love this guy. So a mic in a giant concrete block would have less mechanical movement than in a cage that only evens out the mic moving, except in an environment when the whole ground shakes like near a train or trucks on a road sending a pressure wave in front of them through the ground
Stable mounts and shock mounts do help but wind is a whole other issue as well as handling noise
Your video is Fantabulous !!!! Spot ON !!!! Brilliant !!!! " Super Dave " !!!
So cool and thank you!!!
Great info Dave, makes totally sense .
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@@DaveRat Btw, what sources would you send to the subs except kick and bass .. since most other sources dont operate below 90 Hz, i.e thats why we wanna exclude them ???
Maybe floor tom, keyboards and any playback tracks