[LAU] Record levels lower in Alsa than Jack

[John Murphy]

On Mon, 9 Nov 2020 17:11:22 -0600 "Chris Caudle" wrote:
> On Sat, November 7, 2020 1:04 am, John Murphy wrote:
> > On Fri, 6 Nov 2020 15:19:22 -0600 "Chris Caudle" wrote:
> > Signal Max  : 0.584686 (-4.66 dB)                 32767 (-0.00 dB)
> >
> > That last 'Signal Max' comparison does seem to confirm that
> > normalisation has occurred.
> >  
> 
> That is different than the results on my system, even though I used the
> same SoX command line you showed before.  I don't know if that implies
> some difference between versions of SoX, or different compile time
> options, or different versions of sndfile-lib installed on my system
> (Fedora 33 just for info).
> 
> sox-14.4.2.0-29.fc33.x86_64
  sox 14.4.2-3ubuntu0.18.04.1
> libsndfile-1.0.28-13.fc33.x86_64
  libsndfile 1.0.28-4ubuntu0.18.04.1

Not vastly different here (Mint 19.3)

> I am a bit surprised that change gain would be a default behavior,
> definitely not what I would expect from just attempting to change the file
> format.

Me too. Hence my misconception in the thread title. Happy to know what
was happening and I'll probably use normalisation anyway, from now on.

I'm not sure how I would find SFC_GET_NORM_FLOAT which has a page at:

http://www.mega-nerd.com/libsndfile/command.html#SFC_GET_NORM_FLOAT

Could that setting be making the difference?

-- 
John.