http://bugzilla.opensuse.org/show_bug.cgi?id=922401 --- Comment #5 from Christian Bachmaier <chris@infosun.fim.uni-passau.de> ---
If you click on KMix's icon in the system tray, you should see _two_ volume controls. The left one is the general volume, whereas the right one is the volume for notifications (although it has the same label). If the right one is set to (nearly) 100%, this would exactly cause what you describe: notifications would be played at 100% volume, and also crank up the overall volume to 100% (because of PulseAudio's flat-volumes).
I see 2 sliders. No matter which one (or both) I move to say 25%, playing the next system sound in KDE control panel or e.g. automatically at login time resets (automatically) both to 66% again. This cannot be intended.
So move the right slider to a lower value, about 25% maybe, and your problem should be "solved".
Unfortunately, this has only an effect to a currently playing sound. This was my first and logical try... In the evening I will try flat-volumes = no. The the music player cannot set the master volume any more, but only its own, as far I have red. Chris -- You are receiving this mail because: You are on the CC list for the bug.