Blog by Max Ammann

Pulseaudio: Synchronize Master and PCM

PulseAudio is a network-capable sound server hosted at freedesktop.org. Supported operating systems include Linux, the BSDs, Solaris as well as Microsoft Windows.

Problem

I experienced some weird behaviour with my Logitech: Z10 speakers. Sometimes the volume set on the device differed from my pulseaudio setting. Sometimes they just muted. After playing around with alsamixer I noticed when modifying the PCM channel directly in alsa the volume display updated.

Solution

I just modified the path file for my sink: /usr/share/pulseaudio/alsa-mixer/paths/iec958-stereo-output.conf:

[Element IEC958]
switch = mute

and added a Master element. After merging the PCM element with the Master element everything seemes to work now.

[Element Master]
switch = mute
volume = ignore

[Element PCM]
switch = mute
volume = merge

[Element IEC958]
switch = mute

Note: Master and PCM must be before the actual output element!

Do you have Questions? Send an E-Mail to max@maxammann.org