Volume control in XFCE4 worked fine with the volume control in the indicator-applet, but failed to work with the hotkeys on the keyboard, namely:
- lowering the volume to minimum wouldn't mute
- muting was possible with the keyboard, unmuting was not
Turns out the problem is caused by xfce4-volumed accessing my sound card directly, while the indicator-applet is using pulse audio. Pulseaudio mirrors the controls of the soundcard, but only partially so for some reason. Proper fix for me: Tell xfce4-volumed to use Pulseaudio, but there either isn't a GUI config for that or it's really well hidden. But there is luckily a command line workaround, use:
xfconf-query -c xfce4-mixer -lto get a list of soundcards and then tell xfce4-mixer to use that
xfconf-query -c xfce4-mixer -p /active-card -s PlaybackInternalAudioAnalogStereoPulseAudioMixerNow the volume controls seem to work proper.
Edit: A
killall xfce4-volumed might be needed, as otherwise the setting will be instantly reverted.