[LAU] Normalize to -1db peak

[Atte Jensen]

Hi

I find myself in the need of batch normalizing a lot of wav files (44.1kHz,
24bits) to "-1db peak". I don't know much about the technical details,
although I seem to understand that "-1db" is not as simple as that. I
looked to the command line tool normalize-audio and got quite confused. In
reaper I exported files with the rendering meter maxing at -1, I assume
this is the correct target gain. However if I just run normalize-audio on
the resulting file I get this:

atte at pandrup:~/downloads/normalize_test/test$ normalize-audio 0db.wav
Computing levels...
 0db.wav           100% done, ETA 00:00:00 (batch 100% done, ETA 00:00:00)
Applying adjustment of 4.02dB to 0db.wav...
 0db.wav           100% done, ETA 00:00:00 (batch 100% done, ETA 00:00:00)

So it seems that there's room for 4db of gain, which I find odd, as I
expeced the reaper render to be at -1db. So I looked at the manual, and
found the --amplitude option:

atte at pandrup:~/downloads/normalize_test/test$ normalize-audio
--amplitude=1db 0db.wav
normalize-audio: normalizing to -1.000000 dBFS
Computing levels...
 0db.wav           100% done, ETA 00:00:00 (batch 100% done, ETA 00:00:00)
Applying adjustment of 15.02dB to 0db.wav...
 0db.wav           100% done, ETA 00:00:00 (batch 100% done, ETA 00:00:00)

Looking at the waveform it now looks clipped. Total confusion here...

What is generally meant by "-1db peak", and is there a way to normalize a
wav to "-1 db peak" on the command line.

NB: First post here after switching to gmail, hope post goes through...
-- 
Atte
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