Comment 37 for bug 1406928

Right -- the -14 dB we keep talking about is not a -14dB of headroom (that would be a ratio gain of 0.2 for reference) and we can't treat it that way math-wise.

The replaygain (a literal multiplicative gain) is specifically the difference in loudness function between the track and pink noise file with an RMS loudness of -14dB relative to a full-scale sinusoid. This is supposed to correspond to 89db SPL.

+1 to what Owen is saying -- especially since we have to assume the aux and mic inputs are coming in at "full volume".