Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!malcolm From: malcolm@Apple.COM (Malcolm Slaney) Newsgroups: comp.dsp Subject: Digital Output and VU meters Keywords: digital, DA, VU, video Message-ID: <50010@apple.Apple.COM> Date: 8 Mar 91 01:53:08 GMT Organization: Apple Computer Inc., Cupertino, CA Lines: 21 OK, now for something different....I won't mention the words Ny**ist or ov**samp****.... This isn't all digital but wreck.audio seems hopeless. I have a bunch of digital sounds (both 8 and 16 bit) and I often copy them onto video tape. I was recently copying a tape and it was preceeded by color bars with a 0dB tone. That made it real easy to set the input level on the other deck....just match the 0dB. So, now I want to do the equivalent thing with the digital audio that I'm dubbing onto video tape. The question is....what digital levels would best correspond to 0dB? Should I put in a full-scale sine wave at some frequency and assume that my real signals will be ok? Most of my digital samples are full-scale speech. (i.e. they are scaled just enough so they don't clip.) I don't understand VU meters and tape saturation well enough to know where to start. Perhaps it makes sense to find the peak power in my full-scale digital speech signals, and then generate a sine wave with the same power and call that 0dB. What do people think? Malcolm