Digi Gain Staging

[ebot9000]

Yo D,
I remember having a long conversation with you on the mundane subject of gain staging... I think it was on a death defying descent into Cork several years ago.

After that I did a lot more reading up on the subject, and it made me a lot more aware of setting levels at every stage to ensure I don't have clipping - especially within plugins where little overs might not be noticeable but make the track harsher. But even at the a/d input stage where I turned my input down so my peaks are safely at -16, since you still get full resolution at that point in the digital domain.

Since then I've discovered some things about plugins I didn't know. Like the Waves Ren compressor doesn't peak when it goes over. It applies an L1 limiter. Or this new DAW by Harrison called Mix Bus, that approaches clipping more like an analog board, and compresses instead of clipping. Sometimes I feel like Battery compresses instead of clips (but out of fear I always keep it under 0)

I'm wondering if you could give me (us) your 2010 updated riot act on gain staging. Rules of thumb on keeping everything sounding right, but also any exceptions you've found along the way.

Many thanks,
Ethan

[dennis f]

A few years later and it's still the same theory. lol



1. 0db in the analog domain is not 0db in the digital world.

So all you guys pushing the meters to 0dbfs in Logic/cubase/live/pro tools etc. you are most likely clipping your converters. So what to do? Every manufacturer sets a different standard for their converters. For example 0db in my Aurora 16's was -16dbfs. In my IZ ADA it's adjustable but i keep it standard @ -18dbfs. This means i keep whatever i'm recording to my hard drive no louder than -18dbfs. If your recording at 32bits then don't worry you have plenty of headroom. It's almost an impossibility to clip the file at that rate but you can clip your converters. A simple test to see if i'm bullshitting you..is to use a tone generator plug-in and output a -18dbfs sine wave @1khz to a tape deck or any external fx unit. You'll see it read 0db on it's meter...and you'll go WTF? And when you attempt to bring that output up to 0db in your daw you'll see the deck or external fx smash the redline. This is how i found out about this years ago. I used a compressor and i was wondering why the voxes were distorting and getting crushed. Viola...i found the answer.

2. Watch your gain staging.

Even inserting an Eq plug-in that's just turned on adds gain. In fact sometimes using subtractive techniques adds gain also believe it or not. So for every plug-in you insert and by proxy are chaining to the previous and so on you must take care to watch each plug's input and output so that you stay within the confines of your converters magical 0dbvu = ?dbfs range. Again input -18 (or whatever your converters 0dbvu is at) and output the same. Why? because you could conceivably have a file that was recorded at 0dbfs...and now you insert an eq plug..in which you bring up the mid range...well now it's not 0 dbfs anymore but now it's +2.5dbfs and over killing your converter and you'd never know it unless you switched your metering to Input metering!! Most people just stay on Post fader/post panner metering and think by lowering the fader they've solved the hot input problem. NOPE!!! YOU MUST SWITCH to input metering so you know how hot the file is. You then have a choice of either a. using a gain trim plug to trim down the volume or b. if your in a DAW like cubase use the trim knob at the top of the channel strip to adjust. That's right! That's why they put that there!. lol. See the issue is most people just record a track as hot as they can....while in post fader metering...figure if it's hitting 0db they'll lower the fader and the problem is solved...but is isnt'. Now you add 24 tracks of this crap happening and halfway through your like "God... digital sucks ass!!! My tascam 38 sounded better!! "LMFAO!! Well yeah...cuz you didn't take the time to watch your proper gain staging like you would have if you had an analog mixing board. JUST SMASHING PLUGINS INTO YOUR INSERTS DOESN'T MAKE YOU AN ENGINEER!!! This is why the ballers get the big bucks. The Joseph Puig's, the George Massenburg's, the Chris lord Alge's of the world. They are meticulous in their gain staging.

There is a ton of online resources for those who delve deeper. Bob Katz has an excellent book out. Prosound web forums and the gearslutz forums...do a search..don't act like a noob and ask a question that's been answered 1,000 times. lol

hope this helps