Re: Creating files with RMS gain level instead of Peak

Jeremy Nicoll - ml sox users <[email protected]> writes:

> On 2018-07-07 21:47, Måns Rullgård wrote:
>> Jeremy Nicoll - ml sox users <[email protected]> writes:
>
>>> Yes.  So does that mean that the OP should use something like the
>>> 'stat' effect to find out the peak RMS level of the audio file,
>>> then work out how much gain or attenuation is needed, then use
>>> a 'gain' effect with that calculated value?
>
>> No, he should just use the gain effect.  It adjusts both RMS and peak
>> values by the same amount because that is what happens when you multiply
>> each sample by a fixed amount, which is what the gain effect does.
>
> Yes, I understand that gain is gain, but he has to decide how much
> gain to apply.  If he's previously done that in terms of a pre-gain
> peak level, but now wants to bring RMS levels to a certain point,
> he surely has to find out what the file's RMS levels are first
> then decide how much to modify it by?

The question posed was how to obtain an RMS gain of -12 dB.  The answer
is that RMS gain is equal to peak gain, so "gain -12" will perform the
desired function.  If the question were how much gain to apply in order
to obtain a specific RMS level, then of course the initial value would
have to be known.

-- 
Måns Rullgård

------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot