Recording Levels, gain staging and digital distortion

[Vanman4254]

This is something that gets debated continuously. I have seen people record hot into their DAW.(Im going use Pro Tools LE for this discussion because thats what Im using right now at home) I have seen others record "in the green" going into the DAW. I have worked at studios for people that do it both ways and are very adamant about there method and very much opposed to the other. Let me throw something out here. What if you record hot into PT, then during mixdown you used the trim plug on channels that need turned down? Is this not essentially the same thing? Whether you record low levels first or you just trim the hotter levels later, your still ending up with lower levels during mixdown. I would have to agree that clipping on your 2 bus or Master fader in Pro Tools is totally undesirable, but if you record hot to begin with, are normal gain staging methods such as the trim plug or just turning down the fader not as good as just recording at lower levels to begin with?

Where do you keep your levels while tracking? Where do you keep them during mixdown? Where do you like your levels on your stereo bus or master fader prior to going off to mastering? Are there any sonic benefits to recording at lower levels as opposed to hotter levels? Again, I'm assuming this is for a 24bit recording because that's where I record.

thanks,
and happy hunting

[Dean Roddey]

There's so much silliness in this area out there that it's crazy. Just adjust the output of the last piece in the analog input chain so that your highest peaks aren't above -6dB and you are fine. During the mix, if something is too loud, that's what the track fader is for.

There is zero degredation from using a fader in a DAW because it's just subtracting numbers, and if the highest peaks are not over -6dB, you aren't going to cause any clipping in your plugins on that track so there's no need for any sort of trim plug or anything.

And if the absolute highest peaks (as tracked) are no higher than -6dB, by the time you add a little compression and substractive EQ along the line, by the time it all gets to the main bus, the levels should be fine.

And if you are peaking up around there, then it's unlikely that an unusually loud note is going to clip if you set the levels so that they are up around that level when you are playing hard. If some peaks go over that, it's not a big deal or anything.

It's really kind of that simple, so don't stress out about it. A lot of people have somehow transferred analog audio voodoo to the digital world and it creates crazy beliefs that just refuse to go away.


In a 24 bit DAW you don't NEED the peaks to be up to -6dB, I'm just saying don't make them higher. There's plenty of range to play with, so if some tracks are going to be lower in the mix then there's nothing wrong with recording them a little lower. But it doesn't really make any difference whether you do that or just pull down the fader, and the latter means you have more flexibility as to the final level of the track.

And of course don't push your analog chain too hard just to get to -6dB highest peaks either. If the needs of getting what you want out of the analog chain means the peaks are lower, then that's also fine. But generally you should be able to get plenty o' juice out of the analog gear to get healthy levels.

There's nothing magic about -6dB obviously. It's an arbitrary number like any other. But it works out well to avoid possible clipping, while leaving you plenty of level so that you can afford to give up some to substractive EQ and compression without having to re-boost via makeup gain, ends up leaving you a healthy but not too high level on the main bus, and is probably fairly likely to be what you'll get in terms of worst case peaks if you are running your analog gear at optimal levels.

[Vanman4254]

Cool, thanks for the reply. It makes perfect sense. So I suppose you mean, don't boost anything over -6db on the Pro Tools meter when I'm tracking correct? The only reason I ask this is that I have been around professionals that feel completely opposite as you. Not that I'm saying I don't beleive you. Far from it actually. What you said makes perfect sense.

Im tracking through API Pre's right now that have high headroom. So my meters in PT should not read more than -6db at the peaks while tracking?

I normally have tracked at higher levels than this in the past and usually just turned it down during the mix. I'm not saying that this is ideal either, because I have had problems doing this and trying to Pre Master My stuff with undesirable distortion.

There are still people that feel like tracking with very hot levels get you the most desirable signal to work with. I have not had so much luck doing this way(as I have learned in the past) and I m planning on trying projects with low recording levels in the future.

[Dean Roddey]

Originally Posted by Vanman4254

Cool, thanks for the reply. It makes perfect sense. So I suppose you mean, don't boost anything over -6db on the Pro Tools meter when I'm tracking correct?

Yes. That means the highest peaks. It doesn't mean try to make the highest peaks hit -6dBFS exactly. It just means that the highest peaks shouldn't generally be going above that. If a few happen, it's no big deal. If the highest peak ends up at -9dBFS or -12dBFS, that's no big deal either.

I normally have tracked at higher levels than this in the past and usually just turned it down during the mix. I'm not saying that this is ideal either, because I have had problems doing this and trying to Pre Master My stuff with undesirable distortion.

Some folks would argue that you'll get distortion from the converters if you get really close to 0dB. Whether that's true or not, I dunno. I find it hard to believe that people who make multi-thousand dollar converters are that incompetent. But, it's kind of a moot point because you don't even have to worry about it. Just track lower and you don't have to arbitrarily turn them all down to get reasonable final levels on the main bus and you don't have to worry about clipping.

There are still people that feel like tracking with very hot levels get you the most desirable signal to work with. I have not had so much luck doing this way(as I have learned in the past) and I m planning on trying projects with low recording levels in the future.

There's a lot of confusion on this subject. I think a lot of comes from people not being specific whether they mean the analog chain or the the converters. You might want to run your analog chain pretty hot sometimes if that gives you the sound you want, as long as the output from the last piece in the chain is adjustted to get the appropriate levels into the converters. I guess you can use an inline pad if the last piece in the chain has no separate output level setting and you wanted to push its input hard.

But there's zero sonic benefit in the digital world between peaking at 0dBFS, -6dBFS or -12dBFS really (highest peaks), modulo the possible converter distortion mentioned above. And there's a huge practical benefit to tracking at -6dBFS'ish or somewhat below, in that you have plenty of room for the occasional overly loud note without clipping. And, on the other hand, when all is said and done you'll probably have about what you want on the main bus after all of the tracks lose some level to substractive EQ and compression, without having to push it up many dB to get up to mastered levels in the end.

Someone else might disagree. And there are some folks who argue for tracking at what I'd consider REALLY low levels. But I think that most folks would come out not far from the above.

Some folks argue for tracking with RMS levels, shooting for around -18dBFS, because that's the average level that should be generated when your +4 type pro equipment is outputing around it's optimal output level. But probably the end result will not be too terribly different. I guess that more steady state tracks would tend to be recorded at lower peak levels that way since they would have a higher RMS level? I'm not sure.

[Sqye]

.

you got it wrong:

...first of all, it's:

1. gain staging

2. recording levels

3. digital distortion




.

[Dean Roddey]

Oh, you mean the order of the things in his title. I was scratching my head as to what you were getting at there. The mind is the first thing to go.

[steveschizoid]

Optimum recording Levels - 'Hot' it's not! - it's a great article.

At some point you begin to hear the difference in the timbre of a "hot" recording vs. a more conservative level. A hotter level can then be used as an effect.

[Vanman4254]

That was an excellent article Andy. It was better laid out than most anything I have read on any forum. All of you guys have provided excellent information. Thanks so much. I hope to hear more.

Cheers

[Jack Ruston]

+1 to the above but to add, you should be running your outboard input chain at its optimum working level. You normally find that that approach leaves you with appropriate gain structuring in digital. However there are certain pieces of gear that like to run hot, and as it happens you own some in those APIs. They like to be run almost into the red because they start compressing nicely at those levels on things like guitars and drums. You will find that the resulting digital signal is much too hot. It's worth investing in an attenuator of some sort in order to control the output of those pres. Personally I use an a designs atty.
J

[Vanman4254]

Im running everything through API 512's into apogee rosetta 200. For drums, my overheads go through this chain and the rest of the drums go through the 003 rack + all overdubs go through the API's. So your suggesting to get an attenuator and run the API's Hot? There's no way to adjust the gain on the rosetta, so I usually choose not to run the API's hot. Any suggestions?

[Dean Roddey]

If there's any other hardware in the chain that can bring it back down, you can do it that way. So if you are going into a comp or EQ before the converters and it has an output level, then you could bring it down there.

Though, if you are pushing the pre-amps hard, then you may actually want them to have an input level so you can bring it down pre-EQ or pre-comp potentially, in order not to drive them too hard, which would kind of get you to the same place in terms of finally output as well probably.

If you are going straight in, the ATTY he mentioned is a nicer one. But there are also -5, -10, -20dB inline pads you can use as well, which aren't expensive at all. Don't know if anyone thinks that they do ugly things to your signal the an ATTY doesn't. But it doesnt' seem likely. I mean the ATTY is only like $99 bucks as well, so it's not like it's some kind of mega-audiophile piece o' gear either.

A Designs Audio - Atty Passive Stereo Level Control

[Vanman4254]

Im not using any outboard gear at all. (eq's, compressors). So would it be beneficial for me to invest in the atty? I mean, if I drive the signal on the API's hot, would that eat up the headroom that the API's have to offer? Would it be that much more benficial to drive the pre's hard and turn them down with the atty as opposed to just running a lower signal straight in? What about bringing up the noise floor?

Thanks guys for the replies, this really does help

Cheers

[steveschizoid]

I don't overdrive my 3124 very often; it basically gives a distortion/limiter effect. Soon I will have finished soldering my patchbay , which will allow me to experiment a little more. However, the 3124 puts out a pretty hot signal, so much that I often have to use my Atty2'D to prevent it from clipping the D/A - especially with drums.

[The Bucket]

Whilst were on this subject, I'm using a 512c going into an ADI-2. If I run a steady signal into the 512 and then adjust the gain knob so it reads 0dbvu on the meter, then this signal equates to -14db both on the ADI-2 and within Pro-Tools.

Is this about right?

This is using the 'Lo Gain' Input setting on the ADI-2, the +4dbu and -10dbv settings obviously give you a hotter signal.

Is there any way to calibrate the ADI-2 to -18dbfs? Or am I fine at -14dbfs?

Can anybody shed some light on this please?

[warhead]

Where do you keep your levels while tracking?

I try to peak around -3 at the most to leave some room, but it likely averages -10 on most sources.

Where do you keep them during mixdown?

Well I work with rock bands, and I find that if my kick drum is generally hitting around -10dB on the mix buss that generally I'm going to end up somewhere in the -4 to -3dB range for my max peak in the end. That works for me.

Are there any sonic benefits to recording at lower levels as opposed to hotter levels? Again, I'm assuming this is for a 24bit recording because that's where I record.

Preventing clipping of my analog to digital converter is my primary reason, mixing is relative to everything else going on and as long as I don't have a clipped file or one that's super quiet, I'm cool...

War

[LMS]

so i have been reading alot about this topic tonight. I have put myself in a scenario that i am not happy about and i know that gain staging is the culprit.

in 2009, I was all itb(please please do not start a stupid itb/otb war on this thread....PLEASE!!!!) mixing while running the mix bus out to a c1 and back into PT to print. Everything was real slamming, say around -3db peaks. And the tracks were SUPER quiet. Now i was tracking around -6db into protools so i was getting a good source level and probably keeping my noise floor down.

fast forward to now. I decided to jump in the console pool. Bought a 32 channel Sound Workshop 34c with an API master section. I know, makes me smile everytime i say it. I also have implemented a ton of outboard gear. My mixes sound much much better, BUT, they are noisy.

Ever since i went on this stupid -18 digital equals 0 analog fit, i feel that my mixes have suffered. I calibrated every io of pt, the console, buses, and outboard gear to hit back to pt at -18.

WOHOO. give me a cookie. These mixes are so freaking low that im picking up so much noise. Now i know that some of this is going to be a learning curve for me, but anyone want to chyme in on this? ANy console users want to elaborate on how you are calibrating or what level you are hitting pro tools and your desk with while traking and while mixing?

Grateful minds would like to know.


thanks.

[AstralPStudios]

Basically..Keep your gains between -7 and -3. It's more of a live sound approach but I have to say after being told to record hot and hearing
how much headroom one has keeping gains between those levels sounds
so much cleaner...Would've been nice to learn live sound before recording
lol.

[LMS]

yup. i guess i have been a signal level wus. I'm gonna re-calibrate the studio to a higher level so it is hitting the console hotter.

ugh.

[dualflip]

Originally Posted by LMS

so i have been reading alot about this topic tonight. I have put myself in a scenario that i am not happy about and i know that gain staging is the culprit.

in 2009, I was all itb(please please do not start a stupid itb/otb war on this thread....PLEASE!!!!) mixing while running the mix bus out to a c1 and back into PT to print. Everything was real slamming, say around -3db peaks. And the tracks were SUPER quiet. Now i was tracking around -6db into protools so i was getting a good source level and probably keeping my noise floor down.

fast forward to now. I decided to jump in the console pool. Bought a 32 channel Sound Workshop 34c with an API master section. I know, makes me smile everytime i say it. I also have implemented a ton of outboard gear. My mixes sound much much better, BUT, they are noisy.

Ever since i went on this stupid -18 digital equals 0 analog fit, i feel that my mixes have suffered. I calibrated every io of pt, the console, buses, and outboard gear to hit back to pt at -18.

WOHOO. give me a cookie. These mixes are so freaking low that im picking up so much noise. Now i know that some of this is going to be a learning curve for me, but anyone want to chyme in on this? ANy console users want to elaborate on how you are calibrating or what level you are hitting pro tools and your desk with while traking and while mixing?

Grateful minds would like to know.


thanks.

Hello there, i know what you are talking about and my advice is this: when ppl calibrate their equipment they use 1khz sinewaves most of the time, a sinewave is what would be translated into a steady, full volume sound, but its far from real life, because almost none of the instruments you are recording will be a steady constant signal at full volume.

So, what i ended up doing which is totally against the "rule" and some ppl wont like it is either calibrate your gear higher (perhaps 0VU=-12dbfs) which will translate into your meters peaking at around -18dbfs when you record real instruments, or you can do the "guerilla" callibration which is in my opinion far from technical perfection, but closer to reality, the way to do it is instead of using a 1khz sine wave to do the calibration, use something like a kick drum (just make sure to use one and not the entire drum performance, maybe loop it so it doesnt vary that much) and then using that source do the calibration -18dbfs=0vu.

The reason to do this is that a VU meter is a "closer to the way we hear" kind of meter, so while a 1khz signal may keep that meter at 0VU at -18dbfs, something like a snare or a kick drum at the same level may barely move it, so keep that in mind... thats why i also suggested that if you go with sine waves calibrate it higher.

Hope this helps

[LMS]

very very very much so. thanks a ton.

i should have never followed rules. i just had no idea what i was doing so i went by the books.

[camus]

Originally Posted by LMS

so i have been reading alot about this topic tonight. I have put myself in a scenario that i am not happy about and i know that gain staging is the culprit.

in 2009, I was all itb(please please do not start a stupid itb/otb war on this thread....PLEASE!!!!) mixing while running the mix bus out to a c1 and back into PT to print. Everything was real slamming, say around -3db peaks. And the tracks were SUPER quiet. Now i was tracking around -6db into protools so i was getting a good source level and probably keeping my noise floor down.

fast forward to now. I decided to jump in the console pool. Bought a 32 channel Sound Workshop 34c with an API master section. I know, makes me smile everytime i say it. I also have implemented a ton of outboard gear. My mixes sound much much better, BUT, they are noisy.

Ever since i went on this stupid -18 digital equals 0 analog fit, i feel that my mixes have suffered. I calibrated every io of pt, the console, buses, and outboard gear to hit back to pt at -18.

WOHOO. give me a cookie. These mixes are so freaking low that im picking up so much noise. Now i know that some of this is going to be a learning curve for me, but anyone want to chyme in on this? ANy console users want to elaborate on how you are calibrating or what level you are hitting pro tools and your desk with while traking and while mixing?

Grateful minds would like to know.


thanks.

Hi there. Calibrating at higher levels will only reduce the noise floor from the digital converters, which I strongly suspect, is not what is causing your issues. If your noise floor while using your analog console/outboard at 0VU (+4dBU) is unbearably high, then this is a problem that will exist no matter what you decide to calibrate your converters to. You can run you gear extremely hot ABOVE 0VU to get away from the noise floor, but in the long run, this is going to be detrimental to the quality of your work. The reason why your previous ITB workflow sounded quieter wasn't because you were mixing back into PT at higher levels. It's because you were mixing in digital! If you had printed your levels back from the C1 with average (important - don't confuse this with peak level!) levels around 0VU/-18dBFS, I would wager you still wouldn't have had any of the noise issues you are experiencing now. If it is your console/outboard that is introducing the noise floor then you need to start troubleshooting in that particular area to see what exactly is the problem. Have you measured the noise specs on your console?

Understand that there are two separate issues at play here: Analog gain-staging, and the calibration level of your converters. It is important you don't confuse the problems that originate from one with the other. A high noise floor is certainly not the result of the latter, if you're recording in 24 bit.

The reason to do this is that a VU meter is a "closer to the way we hear" kind of meter, so while a 1khz signal may keep that meter at 0VU at -18dbfs, something like a snare or a kick drum at the same level may barely move it, so keep that in mind... thats why i also suggested that if you go with sine waves calibrate it higher.

In fact, this is actually why you would want to calibrate 0VU even lower, to say -20dBFS, not higher! The lower your calibration level, the harder you can hit your preamp BEFORE the digital recorder distorts. But I agree, the lack of VU meters all around is partly the reason for all the confusion nowadays. Confusing peak level on your DAW meters with rms loudness is never a good idea...

[dualflip]

Originally Posted by camus

In fact, this is actually why you would want to calibrate 0VU even lower, to say -20dBFS, not higher! The lower your calibration level, the harder you can hit your preamp BEFORE the digital recorder distorts. But I agree, the lack of VU meters all around is partly the reason for all the confusion nowadays. Confusing peak level on your DAW meters with rms loudness is never a good idea...

Its unlikely that the DAW will clip if you calibrate it a little bit higher

[dualflip]

Ohhh crap i just realized i got confused i was thinking more in the reading or meter calibration rather than gain staging, however my first post on the "guerilla" calibration still stands valid in my opinion since that at least in my case is what best worked for me in one situation. The opposite (what you are mentioning) is also valid, i just remembered a situation that happened to me recently. I was taking a signal out from my daw into an 1176 and the output to a Q8 channel strip.

So it was DAW->1176->Q8, i had my Q8 fader at unity gain, and i had a decent amount of hum, i raised the output of the 1176 and lowered the output fader in the Q8, and the hum was gone, therefore thats a good example of what you are mentioning, which would translate into raising the pre-amp before it hits the converters.

However I still think that the best would be to check each device in the gain chain and see up to which point the signal becomes noisy.

[camus]

Originally Posted by dualflip

Its unlikely that the DAW will clip if you calibrate it a little bit higher, and now that you mention the pre-amp, perhaps theres where the problem lies in, since if your daw is calibrated at 0VU= -18dbfs you would have to raise the preamp a bit more than if you calibrate it at -12dbfs so perhaps the preamp is the one inducing the noise...

But why would you have to raise the preamp a bit more? If you calibrate 0VU at -18dBFS with the intention of raising the preamp gain to hit a 'higher' level in the DAW then that is defeating the purpose of the calibration in the first place! 0VU analog will STILL be +4dBU whether or not you record it at -18 or -12dBFS. The only thing you gain from calibrating higher is a reduction in the digital noisefloor, but is 6dB that big an issue given that it is -144dB (at 24 bit) below digital zero to begin with? Theoretically, you could calibrate 0VU to -60dBFS and STILL have a digital dynamic range comparable to the finest analog!

[camus]

Originally Posted by dualflip

Ohhh crap i just realized i got confused i was thinking more in the reading or meter calibration rather than gain staging, however my first post on the "guerilla" calibration still stands valid in my opinion since that at least in my case is what best worked for me in one situation. The opposite (what you are mentioning) is also valid, i just remembered a situation that happened to me recently. I was taking a signal out from my daw into an 1176 and the output to a Q8 channel strip.

So it was DAW->1176->Q8, i had my Q8 fader at unity gain, and i had a decent amount of hum, i raised the output of the 1176 and lowered the output fader in the Q8, and the hum was gone, therefore thats a good example of what you are mentioning, which would translate into raising the pre-amp before it hits the converters.

However I still think that the best would be to check each device in the gain chain and see up to which point the signal becomes noisy.

Yup, when you move from ITB to outboard, it is tempting to let the old habits stay! You rarely need to check output levels and such in plugin comps when mixing digitally, but in the analog domain, this is critical! How many people just look at the gain reduction meter on their expensive hardware comps without switching to check the VU meter on the output levels? Unlike ITB mixing, you really have to be meticulous and monitor ALL your output stages to make sure they are neither distorting nor operating way below NOMINAL LEVEL (i.e. introducing noise!)...

[MonsterGT]

I've found this thread very helpful. Thanks all for your input so far.

Would someone be kind enough to touch more on "gain staging?" What is it, and why is it important? I have an idea, but I'd like to get a concrete explanation.

Thanks guys!thumbsup

[joeq]

Originally Posted by camus

Yup, when you move from ITB to outboard, it is tempting to let the old habits stay!

ok, NOW I feel old

[mikethedrummer]

I love how we all stress about the small things the difference between recording at -15db vs -6 is so minuscule. As long as nothing is peaking then GOOD. You can always make the transients bigger in the edit window.
Sonically, yes, as long as you aren't distorting great. If you have a noisy room (w computer fans or air conditioners) then track a little hotter because after 45 tracks that HUMMMM is 45 times louder.
As long as you are anywhere in between you're FINE, you're GOLDEN. Focus on placing the mics better and composing the best music possible!

[ron florentine]

My yellow is my new red..................recently I did a record where I pretty much only hit 1 yellow led....which I believe is about -12 ........I always used to record where my peaks were at -3............I mix OTB through a Neotek console out into a ton of outboard gear and since I have been recording at much lower levels my mixes sound sound much more open and have much more depth of field.



Ron florentine
Soundswest Studio