Limit PulseAudio volume to prevent overdrive

Question

Is it possible to limit maximum volume in PulseAudio? Currently, PulseAudio sets PCM channel too loud which results in distorted sound. I use aumix to turn volume down, but whenever any other sound is played (IM notification etc), PA plays with knobs, turning master volume down and PCM up.

aumix  ++++++++++++++++++++O+++++<Vol      
       ++++++++++++++++++++O+++++ Pcm            ++++++++++++O+++++++++++++

becomes:

aumix  ++++++++++++++++O+++++++++<Vol  
       ++++++++++++++++++++++++O+ Pcm            ++++++++++++O+++++++++++++

I use OpenSUSE 11.2, pulseaudio 0.9.21, ALSA 1.0.21 and ALC889A sound codec.

Answer 1

I had to set flat-volumes = no in /etc/pulse/daemon.conf in Fedora to stop apps from screwing with volumes. Don't forget to restart PulseAudio after the change.

Answer 2

There is a way to stop PulseAudio messing with your PCM level.

See http://askubuntu.com/questions/32383/adjust-pcm-volume for details.

My only issue with this solution is that on every boot, PA does not remember where on it's scale and will show that you're att 100% even though it is the same as when you started. To solve this just drag it all the way down, and then back up again.