[LAU] Normalize to -1db peak

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@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@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