Mixing Console Gain Structure

[Skye]

My professor in class today mentioned that when he mixes, he sets the gain for each channel so he can keep the fader right around unity.

I raised my hand and asked if he was sure this was the proper way to do it. I remembered that my console's manual specifically described mixing with the gain knobs instead of the faders and described it as wrong for various reasons. I remember it because I always used to mix with the gain knobs when I was a lot younger simply because I'm a neat freak.

But my professor said that anytime you're dealing with a console that costs less than $10,000 - $20,000, having the faders far from unity changes and degrades the sound. He said it introduces phasing issues and also frequency abnormalities, but this is less the case on more expensive brands (he listed a few expensive brands, but Midas was the only one I knew already). He said he discovered this when he was mixing drums years ago and he noticed major bass cutoff on the kick mic when he lowered the fader. He thought it was an anomaly for that specific board, but he noticed the same thing on an identical board owned by someone else. So he says we should always set the gain so the faders all sit roughly at unity. He said that his good friend that he talks to weekly mixes for big bands, like Audio Adrenaline and DC Talk, and he does it the same way. Of course he doesn't change the gain during the performance, but still...

A direct quote from my console's manual (A&H GL2400) that I mentioned (but didn't quote) in class is as follows:

Mixing with faders or gain controls? There is a technique
used by some operators where they set all the faders to ‘0’ position and balance the mix using the channel gain controls. We do not advise this method as the signal to noise ratio and control resolution can be severely degraded. In addition, it is impossible to mix monitors from FOH in this way as changes to the gain settings affect the monitors too.

The correct method is to use GAIN to match the source to the operating level of the channel for optimum dynamic range, and then use the FADERS to balance each source into the mix. With correct system gain structure, prime sources such as vocals would have their faders operated around ‘0’ while sources low in the mix such as backing vocals and acoustically loud brass and drums would display their true contribution with their lower fader positions. This is a much more visual and accurate way of mixing.

Well, which is it?

[MrJulius]

On my board I generally push the gain until I start getting a little hum/solid signal (depends on the mic and background noise) then the fader follows to fit the mix. On my mackie CFX it starts getting noisy if I push the fader too high so I try and avoid it, but I have had no problems with way low.

[Kronos147]

Originally Posted by Skye

I raised my hand and asked if he was sure this was the proper way to do it.

Ooooooooo, you started the cycle:

1. Question - Is keeping the faders at unity and using (not using) the gain knobs the 'proper' way (assuming proper is the least amount of noise and best sounding to you).

2. Hypothesize - __________________________________________
(I'll give you an example - using the gain knob adds unwanted noise compared to not using it.)

3. Materials - __________________________________________
(I'll give you an example - mixing console, mix down method or device, song....)

4. Procedures - __________________________________________
(I'll give you an example - mix the song both ways, document the process.)

5. Observations - __________________________________________

6. Conclusion - __________________________________________

Good luck!

[conquest]

Was your professor teaching live or studio mixing when giving his demonstration?

[Skye]

The class is generally geared towards live sound, as was the lecture. I assume that if he's right, if a cheap mixer, say my GL2400, sounds poor if the fader is set at -60, then it would be the same whether I'm using it in the studio or live.

My professor has worked live sound for many years, some as FOH, but quite a bit of monitor mixing too. He's also gone the studio route and worked with bands like Go Fish, Mint Condition, and a bunch of others I can't think of.

He's very clear that he doesn't understand the technical knowledge behind many things. He could go crazy over figures and specifications and not learn a thing, but his ears tell him how something works and how to use it. When his ears tell him something, he doesn't bother to see if the technical data backs it up. For example, he said an electrician would say the sound quality of a cheap mixer (below $20,000) is the same whether the volume is at unity or far lower.

[aussie_techie]

gain match the channel to the source and then leave the gain and mix with faders. once gains are set you shouldnt have to change them unless sometime on stage changes or the gain staging of an insert changes. everything else being equal (not that it ever is live) most faders will be at a similar level either at unity or slightly above or below. you should also start with your master faders at unity, but use your sub groups to their potential. of course once you know a system you may break the rules on purpose but you have learn the rules before you break them. one example is if your running a small scale system you may need to keep the desk level low so you would set gains channel faders and master faders all lower than you otherwise would. or with a GL using a PAD raises the input impedance so you may choose to not use a pad and run the pres hotter or vise versa in order to match your mics better as changing the loading will affect different mics differently.

buying a console and not using faders is a waste on money buying that fader in the first place.

[theblue1]

Originally Posted by Skye

My professor in class today mentioned that when he mixes, he sets the gain for each channel so he can keep the fader right around unity.

I raised my hand and asked if he was sure this was the proper way to do it. I remembered that my console's manual specifically described mixing with the gain knobs instead of the faders and described it as wrong for various reasons. I remember it because I always used to mix with the gain knobs when I was a lot younger simply because I'm a neat freak.

But my professor said that anytime you're dealing with a console that costs less than $10,000 - $20,000, having the faders far from unity changes and degrades the sound. He said it introduces phasing issues and also frequency abnormalities, but this is less the case on more expensive brands (he listed a few expensive brands, but Midas was the only one I knew already). He said he discovered this when he was mixing drums years ago and he noticed major bass cutoff on the kick mic when he lowered the fader. He thought it was an anomaly for that specific board, but he noticed the same thing on an identical board owned by someone else. So he says we should always set the gain so the faders all sit roughly at unity. He said that his good friend that he talks to weekly mixes for big bands, like Audio Adrenaline and DC Talk, and he does it the same way. Of course he doesn't change the gain during the performance, but still...

A direct quote from my console's manual (A&H GL2400) that I mentioned (but didn't quote) in class is as follows:

Mixing with faders or gain controls? There is a technique
used by some operators where they set all the faders to ‘0’ position and balance the mix using the channel gain controls. We do not advise this method as the signal to noise ratio and control resolution can be severely degraded. In addition, it is impossible to mix monitors from FOH in this way as changes to the gain settings affect the monitors too.

The correct method is to use GAIN to match the source to the operating level of the channel for optimum dynamic range, and then use the FADERS to balance each source into the mix. With correct system gain structure, prime sources such as vocals would have their faders operated around ‘0’ while sources low in the mix such as backing vocals and acoustically loud brass and drums would display their true contribution with their lower fader positions. This is a much more visual and accurate way of mixing.

Well, which is it?

Imagine... your manual is correct.


Funny you should bring this up.

I went to two different community colleges that both had pioneering commercial recording classes (this is So. California, after all) back in the early 80s.

One was very professional, by the book, the teacher had run a studio for years. The other was, let's just say, not.

I started at the latter and tested into the former. They administered the test to between 300 and 500 applicants every year and took the top 90 -- my teacher at the not-so-by-the-book school also took the test (and passed) but got a lower score than me, which, frankly did not surprise me.


Anyhow, one of the bons mots from the not-so-pro teacher was that we should gainstage in the same backwards fashion that your teacher suggested.

This, of course, contradicted everything I knew about mixing board practice, everything basic signal flow logic told me about gainstaging, the way the board was laid out and, finally, what the more experienced teacher at the by-the-book school said. (Come to think of it, I think I checked the Woram book that was our text at the by the book, school, as well.)

But, far as I know, this guy kept on teaching kids the backasswards way.

God love him.

[theblue1]

Originally Posted by Skye

[...]

He's very clear that he doesn't understand the technical knowledge behind many things. He could go crazy over figures and specifications and not learn a thing, but his ears tell him how something works and how to use it. When his ears tell him something, he doesn't bother to see if the technical data backs it up. [...]

In the past, I've often said that your ears are the most important piece of gear you'll ever own.

But I'm tempted to now add that the brain is equally important.

At any rate, if the signal is degraded on a given board at the short end of the throw, that will be something that will show up in measurement.

The ears and brain are amazing tools that can do incredible things -- but they are not very good at objective, standardized measurement.

We're all familiar (or certainly should be) with the Fletcher-Munson Curve, which describes the radically varying perception of loudness at different frequencies of the human auditory system. It's the most obvious -- but only one of many "non-linearities" in human perception of sound. One's hearing changes from day to day, even from hour to hour. Changes in health and body chemistry affect hearing. And, of course, hearing is idiosyncratic to each organism; each pair of ears and each nervous system is a little different. (And we won't even go into the highly irregular resonance responses of most less than ideal listening environments, the huge changes in perceived sound that can come from relatively small changes in listening postition or angle.)

Audio analytical tools, by contrast, are extremely accurate in very narrow ways. They can be calibrated and standardized, allowing for meaningful communication of performance details. And they are far more sensitive than human ears -- at the very narrow point of measurement.

A smart person uses both tools for what they do best, and balances what each tells him against what he knows about the performance characteristics of the other.


Maybe your teacher formed his approach on very poorly designed or performing mixing boards. Maybe he's simply fooled by his ear's alinear response as he pulls down the fader. Who is to say?

But I can tell you one thing, if mixing boards were designed to leave the faders in one spot and mix with the trim pots -- they would not be designed with wee, tiny little knob pots way at the top of the strip for trim and big, luxurious, smooth-gliding slider pots handily at the near edge of the board for channel output faders.

Really.

[aussie_techie]

you have to know the theory before you do the practical. then you already know what will be right and its just a matter of putting into action.

guess where the best place to start with for theory and practical, THE MANUAL. everyone should read manuals of gear they dont even own to get the same information. manuals from truly professional companies explain concepts as well as their own gear. hell even behringer manuals explain wiring and most people cant even get that right.

[watersedge1234]

This theory, while functional to an extent, is not practical in real world applications (especially live). As previously stated, mixing via pres will affect everything in the chain, including sends, and thus will change the stage mix with each preamp turn. While I am not saying you should question your teacher *we all know how well that goes *, rest assured that you are correct in questioning his teachings.

Phase issues? You have to ask yourself...in a live situation, on what instruments are you worried about phase? Typically you would only run one mic on each instument, so phase wouldn't be a concern. And on something that is ran in stereo, like overheads or stereo keys, you would typically run the preamps and faders at a similar volume...so any phase issues that arise end up being symmetrical and therefore wouldn't be considered "problems" if you ask me. As long as the overheads/keys stereo channels are in phase with one another, there should be no detriment to the overall mix.

All in all, your teacher is sadly mistaken. It is upsetting to see all the misinformation that is thrown around in "recording" classes these days. I recently went to a school to help record a demo for some friends and found pro tools to be setup in a virtually unusable configuration *such as the buffer settings being set at 512 on their "tracking" station* and it saddens me. Everyone thinks they are a recording engineer these days...

Now what your teacher SHOULD'VE added was that going over unity gain with your faders is what you should be most careful about. There are conflicting ideas concerning this theory, but *IMHO* the golden rule is - pres are made for gain, and should be the only place you get it. If you are pushing faders over unity gain you are adding gain with a device that is not created to do so, thereby adding potential noise/distortion to the mix. It's all about gain structure baby...

[aussie_techie]

Originally Posted by watersedge1234

Phase issues? You have to ask yourself...in a live situation, on what instruments are you worried about phase? Typically you would only run one mic on each instument, so phase wouldn't be a concern. And on something that is ran in stereo, like overheads or stereo keys, you would typically run the preamps and faders at a similar volume...so any phase issues that arise end up being symmetrical and therefore wouldn't be considered "problems" if you ask me. As long as the overheads/keys stereo channels are in phase with one another, there should be no detriment to the overall mix.

phase issues are everywhere in a live system and you have to consider phase on everything. Very few system you will come across are time aligned (even fewer correctly) so you have to consider the phase of everything on stage relative to the PA. and all the drivers wired in phase in front loaded cabs or are some reverse loaded and whats the relative phase of them. its not uncommon to have top and bottom snare mics (in theory the phase will be opposite but theory isnt always right) all drums to each other and to OH, there's also the question of do you gate drums? multiple guitar cabs and multi micing cabs. The phase of foldbacks relative to FOH, phase on individual instruments in FB, vocals being the huge one. the possibilities never end, if more people actually paid attention to ime and phase differences most PAs would sound much better and you can achieve much for clarity at lower volumes.

[watersedge1234]

Originally Posted by aussie_techie

phase issues are everywhere in a live system and you have to consider phase on everything. Very few system you will come across are time aligned (even fewer correctly) so you have to consider the phase of everything on stage relative to the PA. and all the drivers wired in phase in front loaded cabs or are some reverse loaded and whats the relative phase of them. its not uncommon to have top and bottom snare mics (in theory the phase will be opposite but theory isnt always right) all drums to each other and to OH, there's also the question of do you gate drums? multiple guitar cabs and multi micing cabs. The phase of foldbacks relative to FOH, phase on individual instruments in FB, vocals being the huge one. the possibilities never end, if more people actually paid attention to ime and phase differences most PAs would sound much better and you can achieve much for clarity at lower volumes.

Trust me, I realize this. But time aligning really holds no bearing on what this thread is discussing, so I didn't feel the need to add that into the equation. And no matter how much attention you pay to the respective phase issues on the live front, there will be some problems no matter what you do. Factor in bleed from other mics/standing waves/subpar rooms, and you have a phase nightmare. Regardless, this is not a "how to set up a pa" discussion, rather how potentiometers affect the timbre/phase of its respective sources. I am NOT saying phase does not apply to a live scenario, and in many cases is more important than recorded situations. I'm just saying that for many scenarios, mixing via pres is silly and impractical. Do what you will, but you won't catch me running the board that way...

I guess I should've been a bit more specific when i said "phase issues?", it did come off as a bit too broad of a statement.

[Weasel9992]

Originally Posted by aussie_techie

gain match the channel to the source and then leave the gain and mix with faders. once gains are set you shouldnt have to change them unless sometime on stage changes or the gain staging of an insert changes. everything else being equal (not that it ever is live) most faders will be at a similar level either at unity or slightly above or below. you should also start with your master faders at unity, but use your sub groups to their potential.

That's the way to do it live. I'm not sure why anyone would want to try and mix with the gain knobs.

Frank

[theblue1]

You guys seem to have wandered off onto a pretty peripheral issue there...


To swing back around: what the OP's teacher was saying was that his ears had told him that at the short end of the throw of faders, there are supposedly EQ and phase problems (and perhaps other degradations) and that this is especially true for less expensive boards...

... and that that is why one should ignore the way the board is designed, ignore the manufacturer's explicit instructions on how to gainstage the board, ignore accepted best practice, and ignore the basic logic of gain staging and leave your faders at unity and mix with the wee, tiny little trim pot knobs, instead, despite the fact that, as the quoted board manual and a number of us here have suggested, that mixing with the trim pots will tend to cause a ripple effect, changing (hopefully carefully set) levels of sends to FX or cue mixes, etc.


The real question here is how did this instructor get his job in the first place and how does he keep it?


In the case of the instructor I cited in my decades-old reminiscence above, I know the answers to those questions and, frankly, they are extremely discomforting but, perhaps, not entirely surprising. That instructor's lack of knowledge was actually the least of the problems with his time as head of the nascent commercial recording program at that school. There were also overlapping financial and malfeasance scandals. He lost his position as head of the program but later, reportedly because of personal connections within the department, was granted tenure, even though he only had a bachelor's degree instead of a master's. (He was hired as an instructor before he had anything but a H.S. degree, with the understanding that he finish his two year associate's degree in electrical engineering.) It's a disturbing story of taxpayer money poorly used, improperly monitored, and undercutting the proper education of students. It was a long time ago... I just thought... maybe the OP's teacher is one of the poor, benighted souls taught by my former teacher who actually then never got the correct information. One teacher can change many lives... for good or ill...

[CAMGRec]

Before everyone jumps on the professor, it sounds like Skye needs to follow up for more clarification.

Originally Posted by Skye

My professor in class today mentioned that when he mixes, he sets the gain for each channel so he can keep the fader right around unity. I raised my hand and asked if he was sure this was the proper way to do it. I remembered that my console's manual specifically described mixing with the gain knobs instead of the faders and described it as wrong for various reasons.

It sounds like what your professor is doing is right - you should set the gain for each channel such that the fader sits right around unity. I don't see where your professor said that you should then go on to adjust the volume of individual channels in the overall mix via the gain knob and not the fader? And really, if you're having to drastically move a fader up or down to balance that channel in the overall mix, it sounds to me like you're doing it wrong.

Perhaps you should follow up with your professor for clarification? If he does in fact state that he actually mixes a band live using the gain knobs and not the faders, then I would be suspicious.

[treccatrak]

the manual is right about one thing, don't mix with the gain knob. mix with faders. the point is keep the gain as low as you can for cleaner sound. clean sound all depends on the many different variables of course(board, mics, speakers, power, drive system, etc), but the lower the gain on a mic, the less other stuff it picks up around it. this will make sense on drums, where you have many mics in close proximity to each other. the only thing i want my hat and overhead mics to give me out front is cymbals, not the whole kit. a good way to ensure the lowest possible gain is to start the fader at unity and set your gain at the volume you want in the room. you can also learn a lot about gain stage mixing monitors. the higher the gain on the pre, the more likely to have feedback you will be.

[theblue1]

Originally Posted by treccatrak

the manual is right about one thing, don't mix with the gain knob. mix with faders. the point is keep the gain as low as you can for cleaner sound. clean sound all depends on the many different variables of course(board, mics, speakers, power, drive system, etc), but the lower the gain on a mic, the less other stuff it picks up around it. this will make sense on drums, where you have many mics in close proximity to each other. the only thing i want my hat and overhead mics to give me out front is cymbals, not the whole kit. a good way to ensure the lowest possible gain is to start the fader at unity and set your gain at the volume you want in the room. you can also learn a lot about gain stage mixing monitors. the higher the gain on the pre, the more likely to have feedback you will be.

Your logic is deeply flawed.

Changing the trim only changes the overall level of the signal from that that mic going through the channel -- it does not change the level relationship of various components in the signal that the mic picks up. [Read that again.]

(Proviso: changing the gain of a mic preamp can change the impedance relationship between the mic and the preamp and that can change the frequency response characteristics of that circuit.)

To properly set the gain staging for a conventional mixing board that does not have individual pre-fader meters for each channel:

• Route the signal to a metered buss. If the metering is post-buss-fader, set that buss fader to unity.
• Set the individual channel output fader (typically a slider pot) to unity.
• The steps above set you up so that your buss meter will reflect the level going into the individual channel in question.
• With the expected signal coming into that channel, now you can set the trim pot for optimal gain going into the channel.
• Once the channel's optimal input level is set, then you can set the monitoring/mixing level for that channel using the channel's output fader (the slider).

This accepted best practice not only assures that the gain staging in the individual channel is optimized for best signal to noise ratio, it also allows one to create different cue and/or FX sends that will be independent of the channel's output fader (depending on the pre/post settings or fixed routing of the send, that is).

Now -- if the overall level of the input signal changes -- say a mic is moved or an amp turned up -- then you want to readjust the trim pot to re-optimize the channel's gain.



Now -- all that said -- there may well be times when it is convenient to trade off properly optimized gain structure for the convenience of having one or more faders set to the unity gain position while mixing. You'll potentially be losing signal quality by so doing, but you may find circumstances where the tradeoff is worth it.


And, finally, IF one is using some board that demonstrably does have degraded signal quality at the short end of the output slider throws (big if), you may find it necessary to go with a less than optimal gain structure for that channel if your mix requires a very low level for that channel that would otherwise require the output fader to be in the 'degraded' level range.

But -- geez -- for crying out loud do not approach all boards as though they were inferior/defective. Do not build your practice around an emergency corrective measure.

AND -- if you are an instructor or simply a mentor -- please make sure the practice you are passing along actually makes sense and is generally accepted best practice.

[Skye]

When I was young, I mixed with the gain pots because I thought the mixer looked cleaner that way. But we didn't have auxiliaries to worry about, much less effects returns.

My prof. doesn't continue to mix with gain knobs during the performance, but he sets the gain so the fader at unity will be roughly the appropriate volume level. Of course mixing with the gain knob would cause problems, turning all your pre-fader auxiliaries into posts.

So the difference is when you first have the sound check. Do set the gain so that when you solo the channel, the peaks are around +6 decibels? Then you'd have some faders high and others low, depending on how loud you need the various instruments ... or do you take into account that some instruments are not meant to overpower the sound, say a pad or an organ, and you set the gain far lower than peaking at +6 so you can keep all the faders roughly around unity?

As for the boards he's worked on, of course he's worked on some cheap boards, but he's also worked on some really first class consoles for many years. It seems he's been everywhere. Why is he teaching, you may ask? Because as much as he loves music, he feels called into something else, so he's teaching us to support his family as he gets his masters in theology.

[theblue1]

Originally Posted by Skye

When I was young, I mixed with the gain pots because I thought the mixer looked cleaner that way. But we didn't have auxiliaries to worry about, much less effects returns.

My prof. doesn't continue to mix with gain knobs during the performance, but he sets the gain so the fader at unity will be roughly the appropriate volume level. Of course mixing with the gain knob would cause problems, turning all your pre-fader auxiliaries into posts.

So the difference is when you first have the sound check. Do set the gain so that when you solo the channel, the peaks are around +6 decibels? Then you'd have some faders high and others low, depending on how loud you need the various instruments ... or do you take into account that some instruments are not meant to overpower the sound, say a pad or an organ, and you set the gain far lower than peaking at +6 so you can keep all the faders roughly around unity?

As for the boards he's worked on, of course he's worked on some cheap boards, but he's also worked on some really first class consoles for many years. It seems he's been everywhere. Why is he teaching, you may ask? Because as much as he loves music, he feels called into something else, so he's teaching us to support his family as he gets his masters in theology.

No reason to think he's not a nice guy, with sincere motivations, and possibly quite knowledgeable in many ways.

And, though it looks like you've made a conscientious effort to explain his ideas about this, it's always possible that there's been a breakdown in communications someplace along the way.

Even if not, though, I would suggest that you learn what you can from the guy, even as you double-check and triple-check the information with recognized, authoritative sources (and I don't mean me ).

Maybe he's great at coaxing the best performance out of the talent. Maybe he knows how to keep things on time and organized in the studio (and that's huge). Maybe he's got a secret technique for keeping the producer happy but out of everyone's hair. Everyone has something to give.

[treccatrak]

Originally Posted by theblue1

Your logic is deeply flawed.

Changing the trim only changes the overall level of the signal from that that mic going through the channel -- it does not change the level relationship of various components in the signal that the mic picks up. [Read that again.]

(Proviso: changing the gain of a mic preamp can change the impedance relationship between the mic and the preamp and that can change the frequency response characteristics of that circuit.)

To properly set the gain staging for a conventional mixing board that does not have individual pre-fader meters for each channel:

• Route the signal to a metered buss. If the metering is post-buss-fader, set that buss fader to unity.
• Set the individual channel output fader (typically a slider pot) to unity.
• The steps above set you up so that your buss meter will reflect the level going into the individual channel in question.
• With the expected signal coming into that channel, now you can set the trim pot for optimal gain going into the channel.
• Once the channel's optimal input level is set, then you can set the monitoring/mixing level for that channel using the channel's output fader (the slider).

This accepted best practice not only assures that the gain staging in the individual channel is optimized for best signal to noise ratio, it also allows one to create different cue and/or FX sends that will be independent of the channel's output fader (depending on the pre/post settings or fixed routing of the send, that is).

Now -- if the overall level of the input signal changes -- say a mic is moved or an amp turned up -- then you want to readjust the trim pot to re-optimize the channel's gain.



Now -- all that said -- there may well be times when it is convenient to trade off properly optimized gain structure for the convenience of having one or more faders set to the unity gain position while mixing. You'll potentially be losing signal quality by so doing, but you may find circumstances where the tradeoff is worth it.


And, finally, IF one is using some board that demonstrably does have degraded signal quality at the short end of the output slider throws (big if), you may find it necessary to go with a less than optimal gain structure for that channel if your mix requires a very low level for that channel that would otherwise require the output fader to be in the 'degraded' level range.

But -- geez -- for crying out loud do not approach all boards as though they were inferior/defective. Do not build your practice around an emergency corrective measure.

AND -- if you are an instructor or simply a mentor -- please make sure the practice you are passing along actually makes sense and is generally accepted best practice.

didn't mean to step on your toes, buddy. sorry to comment on your subject. just tried to keep my advice to 100,000 words or less. well, apparently i didn't give any advice. i'm a novice i guess.........

[camus]

There's a reason why some people might build a rough mix with the line trims, leaving all faders at unity. This is to give yourself maximum fader resolution when you are riding levels during the final mix. Think about it.

Let's say you have a guitar part that's meant to be really soft in the mix. If you used the "set line trims so average signal is around 0VU while in PFL mode" method, you'd have to set the faders way down during the mix. Now if you need to ride the faders during a passage to make a "delicate" mix move, you're basically screwed. Every small adjustment could be a leap of a couple of dB when you're near the bottom of your fader travel.

The reasons your lecturer gave you for balancing a mix this way are basically complete nonsense, but that doesn't mean the technique is not without its advantages.

[theblue1]

Originally Posted by treccatrak

didn't mean to step on your toes, buddy. sorry to comment on your subject. just tried to keep my advice to 100,000 words or less. well, apparently i didn't give any advice. i'm a novice i guess.........

You didn't step on my toes at all. I'm definitely sorry if I seemed dismissive. But I think I explained where I'm coming from. (Perhaps at too great a length but, you know what? I'm getting to the point where I'd like to get in one clear explanation of a given issue and then never have to deal with it again. A naive hope, perhaps.)

Anyhow, no one is infallible -- most certainly not me. I've been corrected a number of times in this and other forums and I always appreciate it when someone shows me the error of my ways or statements.

[theblue1]

Originally Posted by camus

There's a reason why some people might build a rough mix with the line trims, leaving all faders at unity. This is to give yourself maximum fader resolution when you are riding levels during the final mix. Think about it.

Let's say you have a guitar part that's meant to be really soft in the mix. If you used the "set line trims so average signal is around 0VU while in PFL mode" method, you'd have to set the faders way down during the mix. Now if you need to ride the faders during a passage to make a "delicate" mix move, you're basically screwed. Every small adjustment could be a leap of a couple of dB when you're near the bottom of your fader travel.

The reasons your lecturer gave you for balancing a mix this way are basically complete nonsense, but that doesn't mean the technique is not without its advantages.

I don't find this to be much of an issue with logarithmic scale faders, myself. The log scale, to my thinking, gives a nice sense of perceived linearity through its range.

As I noted above, there is no hard fast rule that says one cannot trade off optimal gain staging for convenience or ease of mixing in a particular case.

But we're talking best general practice here.

And I would definitely commend to your attention the passage quoted in the OP from the A&H board documentation for a clear and concise explanation of the issues.

BTW, here's an explainer from the nice folks at Mackie (good luck, guys!) on why they feel log faders are better: Mackie - Log-Taper Faders

[camus]

For all practical purposes, try measuring the distance between 0 to -10 on your desk, and then the distance between -30 and -40. Of course, if you're just using the board as a glorified summing amp then keeping the faders at unity will offer you zero benefit. If you're riding a vocal, a line of ADR or a stem of foley, then the practical fader resolution becomes of greater importance. I can't for the life of me imagine riding 10dB of dynamic range in less than half an inch of fader travel, but hey...

[theblue1]

Again... there is no rule that says one cannot trade off optimal gain staging for convenience or ease of mixing in a particular case.

If you feel it makes it easier on your board to do what you need to do and you're not concerned about the gain staging tradeoff, by all means, do what you feel works best for you. But as long as we are talking generally accepted best practice for gainstaging a conventional board, the section from the A&H manual and my posts and others describe that.

(With regard to your practical example, riding gain on a key vocal -- it's likely that that important vocal will, when the channel is properly gainstaged and the overall mix is developed, likely be up near unity anyhow. If one needs more wiggle room, it may well be worth the tradeoff to tinker the input trim.)




Now, it may be worth pointing out to others not following closely, that what you're suggesting is not the same as what the OP's instructor seems to be saying. If the OP is correct, he seems to be suggesting that one should leave all one's output faders at unity and mix with trims. A substantially different approach to what either you or I put forth.




PS... with regard to unity gain -- unless I'm going going to my board for a saturation effect (far from likely), I treat unity as a target maximum. If, OTOH, someone is running a +6 dB signal into the channel, then he is going to be reducing the amount of usable throw on his slider since he's got to pull it down an extra 6 dB right from the word go. I know that others feel like they get more 'analog warmth' by hitting their boards hard. Maybe on their boards, they do. Every design and every situation is potentially different. My philosophy is this: I want my mixing device (real or virtual) to be clean, transparent, neutral and precise in control. I want my storage medium to be accurate/transparent. And then I will shape the signal using tools specifically designed for that purpose.

[Skye]

I feel a little misunderstood. Let me break down the question (which has already been mostly answered).

Scenario #1: Solo each channel individually and set the gain so it averages around 0db with frequent peaks to +6db. The channels you need loud have their faders at unity, and the channels you need quiet have faders lower than unity.

Scenario #2: Solo each channel individually and set the gain for the loud channels as in the first scenario, but set the gain appropriately lower on the channels you need quieter so that their faders can be close to unity. Of course if the volume needs adjusting during the performance, the gain is left where it is and the faders are used to compensate.

Essentially, do you have all preamps standardized with differences in fader levels, or all faders standardized with differences in preamp levels. And off the same question, do the faders indicate which channels are quieter in the mix than others? Or do you have to solo and look at the metering to tell which channels are quieter in the mix?

And lastly, would a preference for scenario one or two change if you were using a mixer costing $250, $2,500, $25,000, or $250,000? (I mix on consoles in the first two price marks, but I'm curious about the others in theory.)

Hopefully the "OP" is now a little better understood. :-D

[treccatrak]

Originally Posted by theblue1

You didn't step on my toes at all. I'm definitely sorry if I seemed dismissive. But I think I explained where I'm coming from. (Perhaps at too great a length but, you know what? I'm getting to the point where I'd like to get in one clear explanation of a given issue and then never have to deal with it again. A naive hope, perhaps.)

Anyhow, no one is infallible -- most certainly not me. I've been corrected a number of times in this and other forums and I always appreciate it when someone shows me the error of my ways or statements.

cool. you did indeed establish your level of expertise on mixing console gain structure. awesome show. great job. thanks for the knowledge.
that was sarcastic but of course i really do appreciate knowledge, just not the condescending speech. i know how to use a mixing console.

when you have 5-6 bands a night and have never heard any of them, you gotta start somewhere. you certainly don't have much time to experiment with the exact point of perfection with preamp and fader and microphone. that's good to know and all, but not very realistic on the fly. i was trying to explain in a general sense. of course you want the best signal possible with each channel, but its good for someone to learn the basics then gain experience. i've seen guys hang themselves doing live sound because they know everything but have no experience. ever heard an engineer make the house feedback? i have. couldn't believe it! i've also seen a studio recording engineer try to mix live in a small venue and get in trouble looking for that "sweet spot" preamp-mic-fader relationship. he couldnt figure out why the monitors were feeding back (mons from house).

anyway i think the original inquiry has long since been covered.

[treccatrak]

Originally Posted by Skye

I feel a little misunderstood. Let me break down the question (which has already been mostly answered).

Scenario #1: Solo each channel individually and set the gain so it averages around 0db with frequent peaks to +6db. The channels you need loud have their faders at unity, and the channels you need quiet have faders lower than unity.

Scenario #2: Solo each channel individually and set the gain for the loud channels as in the first scenario, but set the gain appropriately lower on the channels you need quieter so that their faders can be close to unity. Of course if the volume needs adjusting during the performance, the gain is left where it is and the faders are used to compensate.

Essentially, do you have all preamps standardized with differences in fader levels, or all faders standardized with differences in preamp levels. And off the same question, do the faders indicate which channels are quieter in the mix than others? Or do you have to solo and look at the metering to tell which channels are quieter in the mix?

And lastly, would a preference for scenario one or two change if you were using a mixer costing $250, $2,500, $25,000, or $250,000? (I mix on consoles in the first two price marks, but I'm curious about the others in theory.)

Hopefully the "OP" is now a little better understood. :-D

sorry dude, people are crazy in forums!

so, i would set the level to peak at 0. that's just me. i have used everything from midas to little yamaha 10 ch mixers. on digital boards like the pm5d or m7 you should gain a little lower even. they tend to start sounding gritty in the high end, or so i've heard from other engineers.

i have used my little yamaha for my own personal shows with different p.a. systems, and it does the job, but i gain as low as possible with it to keep the noise down. its only a little hiss, faint really, but it gets louder when the pres go up. its really clean when i do it that way.

your allen and heath should have better pres than that, so i'm sure you can peak at zero. if monitors are done from the same board then you may have to factor that in and gain lower.

as far as gain on loud or quiet things, look at it more like close mic'ed or at a distance. say, overheads are at a distance. maybe you dont need to set the peak for that at zero. maybe just enough to hear what you want in the p.a.. you should just try it out when you can.

hope that helps! hope i don't get my head taken off again!

[watersedge1234]

Originally Posted by treccatrak

when you have 5-6 bands a night and have never heard any of them, you gotta start somewhere. you certainly don't have much time to experiment with the exact point of perfection with preamp and fader and microphone. that's good to know and all, but not very realistic on the fly. i was trying to explain in a general sense. of course you want the best signal possible with each channel, but its good for someone to learn the basics then gain experience. i've seen guys hang themselves doing live sound because they know everything but have no experience. ever heard an engineer make the house feedback? i have. couldn't believe it! i've also seen a studio recording engineer try to mix live in a small venue and get in trouble looking for that "sweet spot" preamp-mic-fader relationship. he couldnt figure out why the monitors were feeding back (mons from house).

This is where I'm at too, festival style. You are absolutely right - there is typically not enough time to obsess about mic placement/phase relationships/etc, you just place your mics and hope for the best. In time you learn to place mics timely and consistently, and typically get the results you want. But *A LOT* of live sound is all about working with what you've got as quickly and efficiently as possible...and mixing via gain pots is a detriment to this philosophy, especially when you are mixing FOH and wedges from the same console. It might work with DC talk or whatever, but I'd much rather have a bit of headroom on the faders than be forced to push the fader over unity for any extended period of time. *In my humble opinion* gain should be made up only with tools created for that purpose, and nothing else *aka faders above unity*.

Finally, as previously addressed, if you are running most of your faders in the -30 and below range, you need to rework the gain structure for the room. Either the pres are getting slammed, or you grossly overpowered for the room size. In this instance, I would turn down the gain at the graphocs/dsp/amps, or whatever is after the console to better accomodate the board in the chain. Again, its all about gain staging...

[theblue1]

Originally Posted by treccatrak

cool. you did indeed establish your level of expertise on mixing console gain structure. awesome show. great job. thanks for the knowledge.
that was sarcastic but of course i really do appreciate knowledge, just not the condescending speech. i know how to use a mixing console.

when you have 5-6 bands a night and have never heard any of them, you gotta start somewhere. you certainly don't have much time to experiment with the exact point of perfection with preamp and fader and microphone. that's good to know and all, but not very realistic on the fly. i was trying to explain in a general sense. of course you want the best signal possible with each channel, but its good for someone to learn the basics then gain experience. i've seen guys hang themselves doing live sound because they know everything but have no experience. ever heard an engineer make the house feedback? i have. couldn't believe it! i've also seen a studio recording engineer try to mix live in a small venue and get in trouble looking for that "sweet spot" preamp-mic-fader relationship. he couldnt figure out why the monitors were feeding back (mons from house).

anyway i think the original inquiry has long since been covered.

I'm definitely sorry you felt condescended to. It was certainly not my intent.

It's just that, well, you had a fundamental principle wrong. (Now, what you were suggesting -- that turning up the gain will increase the pickup of unwanted sources in relation to the target of that mic -- would be true, in a sense, if the signal was either saturating the preamp or there was a compressor inserted in the chain. And, as I noted, there can definitely be a shifting frequency response with varying gain as the impedance relationship between the mic and preamp changes, and that may affect the apparent balance between signal elements picked up by a single mic.) I wasn't trying to make you feel bad -- I was trying to get the correct info out. So... you know.

If it makes you feel any better -- and I hope it does -- I quite sincerely have no doubt you are a far better SR engineer than I will ever be. And you can take that to the bank. (That said, I don't see that the OP was talking about SR mixing in the first place. Do you?)




By the way, this issue popped up over in the So Much Gear forum. I tried to use the varying viewpoints and issues expressed in this thread to come up with a more succinct and broader explanation: Getting The Right VU Meter Reading