[alsa-devel] alsa-lib: pcm_softvol.c: attenuation curve - it seems to be too quiet at full volume

John L. Utz III john.utz at dmx.com
Sat Jun 23 01:50:06 CEST 2007

Hello All;

I am in release testing with a fix to our product to use 4 channels on
a CMEDIA 8738-MC6 (previously we only used 2 channels on the CMEDIA
and a separate soundcard for the 2 back channels).

The 8738 is a pretty funny old duck of a chip and i am trying to work
around a subset of it's many idiosyncracies. :-)

The most glaring defect is the absence of hard volume on the back
channels *and* that the back channel is louder than the front channel.

Obviously, this is a great candidate for softvol!

Softvol works quite well *except* that the max volume for the rear
channel is now much quieter than it is without softvol. :-(

Is there anything i can do to alter this behavior?

I notice that there is an initial minimal DB in the file:

#define PRESET_MIN_DB		-51.0

is this where everything starts from? if i bump this up, will i get a
higher max volume?



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