--doktor5000 18:27, 9 April 2013 (UTC) @coling:
Feel free to add all the hints and notes which you already provided and which i've collected locally:
general sound/pulseaudio troubleshooting
1. cat /proc/asound/cards 2. getfacl /dev/snd/pcm* 3. sudo fuser -v /dev/snd/pcm*
collecting information about pulseaudio and hardware
pacmd ls
switch off sound (on some mixers)
amixer -c0 amixer -c0 set "IEC958 Default PCM" off
start a shell, where no pulseaudio is running, for troubleshooting
pasuspender bash
play something directly via alsa
aplay -D hw:0 /usr/share/sounds/something.wav
the built in, fixed "priority" assigned to each card is shown in "pacmd list-sinks" output (ditto for list-sources if that matters)
this priority is only used for OOTB behaviour but there could be a bug in KDE where this OOTB is wrong
if the priority order is correctly setting the order we use for a fresh login, then there would be two ways to fix this default.
1. is to edit the profile files in /usr/share/pulseaudio/alsa-mixer/paths/ and assign different weightings which will ultimately flow through to the priority of the sink. 2. is to login once, set the defaults then copy the ~/.pulse/*.tdb files to the /etc/skel folder such that new accounts get these files
if the volume for a particular channel gets always set to 0, and that channel is not available via pavucontrol, how to solve that? via f.ex. alsamixer and alsactl store afterwards and manually autorun alsactl restore?
you shouldn't need to manually run alsactl restore... it should be done automatically at boot, it's just that the user has not activated the right kcontrol = alsa mixer name (as in the labels on alsamixer or amixer output)
In the case of the "speaker", they need to pick a port (or connector as it labelled in gnome-volume-control) that actively uses the speaker.
Otherwise we do not consider it to be part of the mixer path and we actively mute it to prevent any unwanted interference. So the user just needs to pick the right port/connector in an appropriate GUI.
how should one pick a port/connector via gnome-volume-control-applet ? Some kcontrols we genuinely do completely ignore (like the cdrom ones) but "speaker" is one we actively know about. you do not via the applet, it's the full gnome gui you use, which is gnome-volume-control in gnome 2 and available via system settings -> sound in gnome 3. under KDE it's available via system settings -> multimedia -> phonon -> Audio Hardware Setup but it only shows up if your card supports ports/connectors. Mine (for example) does not.
