Re: [LAU] keeping same perceived level on mp3 files

Hallo!

>>> Do you just want to adjust the loudness between multiple files?
>>> (this means there is just a constant gain for every file so the they
>>> are similar on average)
>>> Or do you also want to change the loudness inside one track?
>
> Not sure what you mean. I don't to change the internal volume of each
> track. Basically I just want to avoid that when I program the levels of
> the patches on my hardware synth, I later (on stage or rehearsing with
> the band) realize that on some songs my synth is too loud and on some
> songs it's to soft.

I meant, if you have longer files with a high loudness range, maybe you
should also adjust the loudness of different regions within your file -
but I guess it's not the case ... ;)

> I tried it on a couple of files:
>
> atte@email-addr-hidden:~/music/bands/eldorado/mp3$ ls *.wav | xargs -iarg ebur128 arg
> Integrated loudness: 13.7 LU
> Loudness range: 3.8 LU
> Integrated loudness: 13.0 LU
> Loudness range: 2.2 LU
> Integrated loudness: 6.0 LU
> Loudness range: 3.6 LU
> Integrated loudness: 10.8 LU
> Loudness range: 4.5 LU
> Integrated loudness: 12.9 LU
> Loudness range: 3.2 LU
>
> Ok, so it seems the third file is softer than the rest, which is very
> true. But how do I interpret those values, and how do I call sox for a
> gain adjustment?

That's great - now you only have to bring all your files to the same
loudness!
For example, let's say you want all files to be at 13 LU.
You can apply a simple gain on all files:
-0.7 dB for the first file (13.7LU), 0dB for the second, +7dB for the
third (6LU) and so on ...

I think you can do that with sox - and maybe it's also good to use an
additional limiter (at -1dBFS or lower), to avoid clipping!
AFAIK sox has the compad effect, which can do that ...

Have a nice weekend,
LG
Georg

-- 
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