Path: utzoo!news-server.csri.toronto.edu!rutgers!sun-barr!apple!malcolm
From: malcolm@Apple.COM (Malcolm Slaney)
Newsgroups: comp.dsp
Subject: Re: Digital Output and VU meters
Keywords: digital, DA, VU, video
Message-ID: <50146@apple.Apple.COM>
Date: 12 Mar 91 17:36:42 GMT
References: <50010@apple.Apple.COM> <27517@netcom.COM>
Organization: Apple Computer Inc., Cupertino, CA
Lines: 22

In article <27517@netcom.COM> mcmahan@netcom.COM (Dave Mc Mahan) writes:
>It all depends on the gain of your amplifiers and stuff.  The easiest way
>to do that with the equipment you have is to just record a digital tone
>with a known amplitude and then play it back to see what kind of power shows
>up on the VU meter.  Then, adjust your amplitude to get 0 dB.  

I guess I didn't ask my question very well.

What does 0VU really mean?  I assume it is power related but I'm not sure of
all the nuances.....and I suspect that there is a temporal dimension to it.
Otherwise why would Nackamichi make such a big deal about their peak VU
meters?  Are VU's constant across frequencies?

So, what is 0 VU really mean?  I want to know so that I can consistently 
normalize my speech signals.  The energy in a digital impulse train is very
different from a full-scale sine wave.  Speech is somewhere in between.  Just
how high can I crank the analog gain before I saturate the tape with random
speech data?

Thanks.

								Malcolm