Re: [SoX-users] Fwd: Using sox to normalize rms and peak

[Fmiser <fm...@gm...>]

> Francesco Danieli wrote:

> Hi we are trying to use sox to normalize a bunch of audio
> files to a constant peak and RMS level.
> 
> Ideally sox filename -e stats should read
> 
> Pk lev dB Overall 0
> RMS lev dB Overall -9
> 
> for all our files.
> 
> We managed to obtain the first value with -n option.
> What we are missing is how to get RMS level of the files to
> the desired db,leaving Pk level untouched.
> 
> We tried "gain -ne"  and "gain -nb" but they both vary the Pk
> level. We also tried loudness option but it does not give us
> what we are looking for.

The difference between RMS and peak level is called "crest
factor".  It cannot be change by changing the gain.  The only
way to change the crest factor is with a limiter, compressor,
expander, or gate.  These tools can change the dynamic range and
thus the crest factor. 

But what you are asking is an odd request - so I'm now really
curious _why_ you want normalize both peak and RMS.

--    Philip