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bob katz · 9th May 2006, 02:35 PM

Dear ranierisenni: I'm sure Paul is still here, but I'll chime in. It's the ultimate mix level and how you process the mix that will determine the level. I assume you're going to be mixing samples, reverb, eq, etc. The complex sum of all those elements will have a completely different transient response and level than that measly little sample that might be a small basis for your mix.

A conservative, "very safe" maximum peak level for your 24-bit mix as measured on a simple sample-reading digital meter is -3 dBFS, because the simple digital meter does not read the illegal levels.

If you are mixing totally digitally, then the "intrinsic" level of the samples as they would be played over a D/A converter, for example, does not enter in. It is only an issue if you are feeding a D/A converter for external analog processing. This is what I believe to be true, and just to be safe, I'd like independent confirmation from an authority like Paul.

When you send your mix to the mastering studio----

If the mastering engineer is processing everything digitally, he doesn't have to worry about "intrinsic overs" until the last stage in his processing chain, or until he reaches a sample rate converter, since all digital processors except for sample rate converters work on the "internal" digital value of the samples and whatever comes out, even if it is an illegal signal is not important in the all-digital processing world. I would like Paul to confirm that, but everything I believe says this is true. So your mix could be up to 0 dBFS (if you have an accurate digital meter). At the last stage in his digital chain, the mastering engineer can employ a true brick-wall peak limiter such as the TC System 6000 limiter, which prevents intersample peaks in D/A converters and hopefully also in sample rate converters. Limiters still add distortion, of course, but that's another issue.

If the mastering engineer is processing via analog, and is concerned about distortion, then the first piece he has to worry about (and maybe the only piece) is the D/A converter he uses to feed out to his analog gear. And worst-case scenario in that case is he attenuates the digital level going into the D/A by 0.3 to 3 dB. It avoids the degradation of multiple re-quantizations if you ran your mix at that level to begin with, avoiding one more calculation at the mastering house, but it's not the most serious thing in the world to drop the level and redither it to 24 bits in the digital domain.

Hope that gives a bigger picture of the issue.

9th May 2006, 02:35 PM	#2
bob katz Mastering Join Date: Mar 2006 Posts: 1,826	Dear ranierisenni: I'm sure Paul is still here, but I'll chime in. It's the ultimate mix level and how you process the mix that will determine the level. I assume you're going to be mixing samples, reverb, eq, etc. The complex sum of all those elements will have a completely different transient response and level than that measly little sample that might be a small basis for your mix. A conservative, "very safe" maximum peak level for your 24-bit mix as measured on a simple sample-reading digital meter is -3 dBFS, because the simple digital meter does not read the illegal levels. If you are mixing totally digitally, then the "intrinsic" level of the samples as they would be played over a D/A converter, for example, does not enter in. It is only an issue if you are feeding a D/A converter for external analog processing. This is what I believe to be true, and just to be safe, I'd like independent confirmation from an authority like Paul. When you send your mix to the mastering studio---- If the mastering engineer is processing everything digitally, he doesn't have to worry about "intrinsic overs" until the last stage in his processing chain, or until he reaches a sample rate converter, since all digital processors except for sample rate converters work on the "internal" digital value of the samples and whatever comes out, even if it is an illegal signal is not important in the all-digital processing world. I would like Paul to confirm that, but everything I believe says this is true. So your mix could be up to 0 dBFS (if you have an accurate digital meter). At the last stage in his digital chain, the mastering engineer can employ a true brick-wall peak limiter such as the TC System 6000 limiter, which prevents intersample peaks in D/A converters and hopefully also in sample rate converters. Limiters still add distortion, of course, but that's another issue. If the mastering engineer is processing via analog, and is concerned about distortion, then the first piece he has to worry about (and maybe the only piece) is the D/A converter he uses to feed out to his analog gear. And worst-case scenario in that case is he attenuates the digital level going into the D/A by 0.3 to 3 dB. It avoids the degradation of multiple re-quantizations if you ran your mix at that level to begin with, avoiding one more calculation at the mastering house, but it's not the most serious thing in the world to drop the level and redither it to 24 bits in the digital domain. Hope that gives a bigger picture of the issue. __________________ Bob Katz DIGITAL DOMAIN http://www.digido.com "There are two kinds of fools. One says-this is old and therefore good. The other says-this is new and therefore better." No trees were killed in the sending of this message. However a large number of electrons were terribly inconvenienced. Last edited by bob katz; 9th May 2006 at 02:37 PM..