I never had a problem in WoW or SC2 (although nukes are loud) with my subwoofer being very high.
Its like this: Subwoofer 1000%, everything else: 100%
This is most prominent in diablo fight, and the monk abilities, every time I click its just like BOOOM BOOOM BOOOM BOOOM..... its worse than a dubstep song (not that dubstep is bad!)
I see no option in turning down my subwoofer unless i completely remove it, or manually change it at the subwoofer itself, which I then have to turn back once I have finished diablo.
How can I turn the volume of this down in diablo ?