Re: Question re: levels in digital audio


Subject: Re: Question re: levels in digital audio
From: Andrew Czink (aczink@telus.net)
Date: Thu Oct 20 2005 - 10:38:50 EDT


    No. This is a mistake. I generally normalize to -0.2 or -0.3 dB; ie just
below 0dB FS (Full Scale or 'digital zero'). To use the full resolution of
your system (ie your 'bit depth') your peaks should get above -6dB. If
you're peaking below that you are NOT taking advantage of your system's
resolution. Where the confusion lies (I think) is how this relates to analog
levels. There's an emerging convention amoung music recorders to set 0VU on
your analog mixer to -12dB on your digital recorder. You would then treat
this level like you would 0VU on your mixing board; ie where your average
levels should be, which then leaves you 12dB of headroom for peaks. In the
film world -20db is more common for this calibration. Realize that it's an
arbitrary calibration. I only worry about these conventions when I'm
producing something for a commercial client and the recordings/files move
around from studio to studio and calibration conventions like this ease the
workflow considerably. In my own personal work I ignore this completely and
essentially custom calibrate for everey different sound source I'm
recording. It slows down the workflow a bit, but wrings the most out of your
system.
    Hope that helps.

    Andrew

On 10/19/05 7:26 PM, "Phil Thomson" <hellomynameisphil@gmail.com> wrote:

> Hi all,
>
> I should probably know this, but I have a question about levels in
> digital audio. In my own work, I've always normalized my digital audio
> stuff to 0 dB or similar levels, and have never had any problem with
> distortion or clipping while running my levels at close to 0 dB, but
> lately I've been hearing that -12 dB is the maximum level that you
> should shoot for, because clipping is introduced at even -6 or -8 dB.
> Is this only true of DAT or DV, or is it the case for digital audio
> across the board? I've *never* heard any clipping in my own work (on
> the computer), but the video folks I'm hanging with now claim that -12
> dB is the new 0 dB. What's up?
>
> PT
>
> --
> Phil Thomson, BFA, MFA
> 010100000110100001101001011011000010000001010100011010000110111101101101011100
> 110110111101101110
> hellomynameisphil@gmail.com
> http://www.sfu.ca/~pthomson/
>



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