Best way to reduce master output to -6db?

[mharris]

Do a phase cancellation test and check for yourself.

I'm not sure a phase cancellation test would prove anything anyway, apart from you having two tracks out of phase.

If you bounce down a track, copy it on to 2 tracks and stick one out of phase, of course it will cancel the other out, no matter how hot it is. You'll have the same amount of clipping etc in both tracks, in exactly the same places so it will prove nothing.

Sorry, I didn't make that very clear. Let me explain.. (I think) we are discussing if there is any difference between reducing all individual tracks or just turning down the master. I actually know the answer to this (there is no difference), I'm just posting the question to make other people think about it and to help the OP out.

What I was suggesting is to render a mix with all tracks turned down 6dB and then render a mix with the master turned down 6dB. Do a phase cancellation test of these two renders and discover that it makes absolutely no difference which way you do it. This is assuming that there aren't any analogue modelling, or level dependant plugins on your master track. In this case, you can just put a Utility at the start of the chain and reduce the 6dB there.

Now back to my initial question about the differences between various methods.. There have been 3 or 4 ways suggested in this thread each with people backing them up saying "you should only ever do it this way". I simply wanted to know the technical reasons why one way is suggested over the other because I know from a summing point of view it doesn't make any difference. Unless, of course the summed signal is ridiculously hot.

[grooverb]

Ok I've been doing some reading. From what I understand 0dB on a VU meter is actually -14dB on a digital meter, and that is about where we are aiming for with sound levels.

By making all the channel faders up to a peak of -6 and leaving the master fader at 0, that should equate to an RMS level of about -12, which is tinsy bit over 0dBVU, meaning that when the Master engineer puts it through a properly calibrated system it'll come out about 83dBSPL without needing to be boosted or attenuated therefore avoiding distortion or hiss and making his job a lot easier. 83dBSPL is in the region of 80-90 dBSPL where our hearing is at its flattest frequency response and has been decided on as being the optimal level to master music at.

If we use the master fader or a utility on the master fader to reduce the volume, then I'm guessing it'll put the ratio/level out of whack, and will affect the crest value, meaning the Master Engineer won't be able to get the best out of your piece of music, which is what this is about.

Far as I understand it, Mastering Engineering is best done with the music at specific levels, and its really careful balancing act.

All the 'safety features' that are in Live, I suspect are for live use to make sure that if the levels go up in the red during a performance, it won't bugger up the sound, but doing it for a release is a very different ball game and that is why it is the recommended way to mix down your tracks.

[mharris]

If we use the master fader or a utility on the master fader to reduce the volume, then I'm guessing it'll put the ratio/level out of whack, and will affect the crest value, meaning the Master Engineer won't be able to get the best out of your piece of music, which is what this is about.

So despite the fact that both methods will produce identical* audio files, you still claim that one is better than the other for a mastering engineer?

*By identical I'm counting phase cancellation down to "-inf" on Ableton's meters.

[grooverb]

I don't know. Its what I've read in several books written by people like Bob Katz, and mags Computer Music, Future Music, Sound on Sound, and its what mastering engineers ask for.

If you want to go and tell them all they are wrong feel free. I was hoping you'd bring something a bit better to the table than a smug attitude.

[mharris]

I would have liked to continue this discussion, but as soon as personal insults start getting thrown around on a discussion board its time to go and find something more constructive to be doing.

[grooverb]

fine by me

[friend_kami]

Ok I've been doing some reading. From what I understand 0dB on a VU meter is actually -14dB on a digital meter, and that is about where we are aiming for with sound levels.

By making all the channel faders up to a peak of -6 and leaving the master fader at 0, that should equate to an RMS level of about -12, which is tinsy bit over 0dBVU, meaning that when the Master engineer puts it through a properly calibrated system it'll come out about 83dBSPL without needing to be boosted or attenuated therefore avoiding distortion or hiss and making his job a lot easier. 83dBSPL is in the region of 80-90 dBSPL where our hearing is at its flattest frequency response and has been decided on as being the optimal level to master music at.

If we use the master fader or a utility on the master fader to reduce the volume, then I'm guessing it'll put the ratio/level out of whack, and will affect the crest value, meaning the Master Engineer won't be able to get the best out of your piece of music, which is what this is about.

Far as I understand it, Mastering Engineering is best done with the music at specific levels, and its really careful balancing act.

All the 'safety features' that are in Live, I suspect are for live use to make sure that if the levels go up in the red during a performance, it won't bugger up the sound, but doing it for a release is a very different ball game and that is why it is the recommended way to mix down your tracks.

what?

then I'm guessing it'll put the ratio/level out of whack

..
really?
if you render something out at -6db, then it renders out at -6db, no matter if rendered out at -6db from your master being turned down to -6db, or if it's the combined rms of all your faders resulting at a master at -6db.

what are you talking about?
also, this phase cancellation test that mharris is talking about pretty much explains it all.
if you have two tracks, rendered out at two different settings (in this case, either a master fader down at -6db, or track faders down to -6db) and the result cancels out to freaking -inf db, then the files are identical..

according to you they are not, because one has an altered master fader.
with that in mind, can you explain how two identical files can produce an out of wack ratio on a calirated system?
if one of them does, they both would.