A while ago when I switched from GNOME Shell to Unity, the first thing to bug me was the volume control in the top panel. When I would drag it side to side, it wouldn’t slide smoothly, instead it would jitter and jump back and forwards. This made it almost impossible to select the correct volume. I was convinced that this was an issue with Unity as I never had such an issue with GNOME or KDE.

As it turns out, by random prodding, that the volumes for each channel of audio were different by 3%. By installing pavucontrol and setting the levels equal in pulseaudio, the slider works correctly now. It seems that Unity is not equipped to handle unbalanced channels. The stranger thing is why they were unbalanced in the first place. This isn’t the first time I’ve had to set the balance on startup, but in all the other cases, the balance was usually something obvious like 95% to one side or the other. My audio card is a modified ASUS Xonar Essence STX on which Ubuntu uses the Virtuoso 100 driver by default. Driver bug? Maybe.