legionserial said:
As someone previously mentioned, if you are tracking just below clipping, then whatever piece of analog gear (ie preamp etc) that you are using is going to be being pushed way harder than it should. If its going in at -0.1dbfs, then you are pushing the analog side far to hard for it to get to that level, as it's going to be going at 18 or so db above the analog clipping level of 0dbVU. Surely that's going to detriment the sound. Or that's how I understand it anyway.
OK, I've accepted the fact that this message will have to be repeated over and over again...
First, 0 VU in an analog stage is not the clipping level. It's the reference signal level where the operator will set an averaging meter to read on forte signal peaks. When I set my analog reference level at -20 dBFS, that leaves 20 dB of headroom above that reference level. In my experience, that is just enough in most tracking and mixing situations to make sure that my instantaneous peaks don't reach 0 dBFS.
But here are the important points:
Instantaneous peaks provide very little indication about perceived signal loudness.
Set your levels using an average-measured reference level, leave yourself adequate headroom and then
ignore peak levels entirely, so long as they don't go over.
Remember, instantaneous peaks provide very little indication about perceived signal loudness. Average-measured signal levels tell you how much meat is on the bone, so to speak.
As an aside, note also that if 0 VU corresponds to +4 dBu, and 0 VU is also -20 dBFS, then 0 dBFS is, obviously, +24 dBu.
+4 dBu is fine as a reference signal level in pro studios with only high clip point gear with voltage rails at +28V or +39V and clip points of +28 dBu and tape that only allows 14 dB of crest factor above the reference level, leaving perhaps 10 dB of "cushion" between the loudest peaks and the analog clip points.
Nowadays, the crest factor on digital tracks can be 20 dB, and the clip points of a lot of gear in the home recording world clips below +24 dBu, (RNC clips at +22.5 dBu, for example) and that gear probably starts to sound ugly at 6 dB below the clip point.
So, +4 dBu may be too high a reference level in a home situation with digital recording. If you want the cleanest, most transparent tracks your gear is capable of, plan your gain staging and signal levels accordingly.
Cheers,
Otto