I generally look at the RNDigital plugin during a soundcheck -- it has nice resettable peak displays -- and aim to be around -9dBFS at peaks. Real performance always peaks at least 3dB louder than soundcheck in my experience! Occasionally of course I miscalculate and need to pull the gains down during a track break. With 24-bit recording I feel comfortable recording some distance away from peak; the noise floor is pretty low.
The pre I use doesn't have ganged gain across the channels (an advantage of units like the MOTU Traveler) but it does have stepped gain controls instead of potentiometers, and I've measured them fairly well: channels are matched within about 0.3dB (and I calibrate afterward to adjust for that), but channel gain matching doesn't vary significantly at all with the actual gain setting.
Taking a look at the console programs...
So if I had 4 unmatched levels, I could record a test tone and the software will adjust the gain?
Could you describe the recording of the test tones? Do you record at 4 compass points, or what steps are involved in this process?
And is this 4 mono wav files or 1 interleaved file?
C:\Hugh Pyle>aformat
A-Format file analysis and normalization.
Assuming several channels of audio, each with a calibration
tone of several seconds near the start or end of the track.
Scans the file for 1-second regions where the signal is
greater than -40dB and very constant (lowest standard
deviation of the Hilbert envelope). Typical deviations
with well-recorded calibration tones will be less than 0.05dB.
Reports the relative gains of these calibration signals and
optionally normalizes the file(s) by amplifying each channel
to the gain of the loudest calibration signal (producing 32f WAV).
Usage:
AFormat <infile> [/output <outfile>] [/gain n] [/cal n] [/test n] [/testmin n]
<infile> (input filename, or * for all WAV files in the current folder)
Optional:
/output <outfile> (output filename)
(use '-' for stdout)
(if not specified, only gain coefficients are calculated)
(if input is '*', this is the 'base' output filename)
/gain <n> (dB; defaults to 0)
/cal <n> (seconds to scan for calibration signals; defaults to 60)
(negative values seek from the end of the file)
(or use a filename if calibration signals are separate)
/test <n> (seconds of cal signal to look for, defaults to 1)
/threshold <n> (dB, defaults to -40)