Bouncing Individual Tracks with Stereo Buss lower than 0 dbs

[Stephen Hare]

I have a quick question.

 

I'm bouncing down some stems for mastering and had lowered the stereo buss to avoid clipping when the mix was played together. When all the audio files were imported at 0 you would have the right mix.

 

But now I realize that I should have put the master output at 0 and then asked the mastering engineer to lower the stereo buss to avoid the clipping then.

 

So; just how big of a difference will this make? I bounced everything at 24 bits and the stereo buss was pulled down 11 dbs. Is there a REAL WORLD sonic difference here? I've listened to the mix and to my ears it's indistinguishable, but maybe for a mastering engineer it would be a pain.

 

It took me about an hour and a half to bounce all the stems and would just like to avoid doing that again. Thanks for any tips.

[David Nahmani]

Is there a REAL WORLD sonic difference here?

 

No. What you're saying is you're going to deliver stems that peak at -11 dB FS instead of 0 dB FS to your mastering engineer correct? That should be no problem when working in 24 bits.

 

PS: out of curiosity only: I've never heard a mastering engineer require stems - what kind of music is it and what kind of stems did he ask? IMO if you're working with stems you're mixing, if you're working with a mixed-down stereo file you're mastering - maybe that mastering engineer wants to help you out with the mixing before actually mastering?

[Stephen Hare]

My room is not treated properly, and so there were some bass issues. Once I started speaking with the mastering engineer we decided that I would chunk up the mix into a few main stems so that he could adjust the levels slightly to work a proper bass boost.

 

In short, he was happy to do a simple master of a stereo track, but this will enable him to boost the bass and kick while enabling the rest to stay relatively the same. Perhaps the overall difference will be imperceptible but so be it.

 

Since I have your attention, a few of the tracks were fairly low in the mix, so their relative peak might be more like -20 db...would that still be ok? When does it become a concern?

 

When you put the audio files back into Logic the waveforms look so puny to what they normally look, it made me nervous!

 

Thanks again.

[David Nahmani]

When you put the audio files back into Logic the waveforms look so puny to what they normally look, it made me nervous!

 

I know... but don't worry about it. When working in 24 bits you have such a huge dynamic range that low levels really aren't a problem. If you're talking about an individual track's peaks, then it really doesn't matter: you place your individual tracks at the level you want in your mix. If you're talking about the Stereo Out, or a stem, then peaking at -20 dB FS is still perfectly ok, although it would be better to peak a bit higher.

 

Consider this:

 

24 bits gives you about 144 dB of dynamic range. If your stem is peaking at -20 dB FS, you're working with a dynamic range of 124 dB. That's still perfectly acceptable.

 

I can't really give you a number of what's acceptable and what's not, the lower the level of your file the less dynamic you're using - and therefore the higher the noise, but you have to put things into perspective. For example, what is the dynamic range of the converters you used to record those tracks? Chances are it's around 110 dB. What was the noise level in the room? What was the noise level of the mic, the mic preamp, etc...? Chances are all those noises are much higher than the noise floor of your audio file even when bounced at -20 dB FS.