[pulseaudio-discuss] PA volume effects

[Daniel Mack]

I'm observing strange audio artefacts with my audio driver which seem to
be related to audio material overamplification. IOW, the effect is only
audible at waveform peaks. When I attenuate the playback volume
pavucontrol, things get a lot worse - horrible distortion all over
the place, even in more quite audio sections.

Also, when comparing the audio output of 'aplay -Dpulse foo.wav' with
'aplay -Dplughw foo.wav', it is clearly audible that PA adds some kind
of amplification to the material (I would guess ~3dB), even though all
GUI accessible levels are set to 100%.

The driver I'm working on does not have any volume control features,
hence this must be done in software.

Has that been encountered before?

Thanks,
Daniel