I'm now curious if I have a similar issue. Until reading this thread I was convinced the Premium Sound option was a waste of money. My E39 540 sound system was much better than my two week old M3's system. Very disappointing. Also frustrated with its limitations compared with the E39's DSP, which allowed for multiple equalizer presets. I also can't figure out if the separate bass and treble controls override the equalizer, or the other way around. Anyone know the answer? Love everything about my M3 except for the sound system.
Delivered 9/4/11: 2011 E90 M3, Le Mans blue, ZCP/ZCV/ZP2, DCT, Premium sound; BMW Performance Exhaust, CF Splitters, and "Black chrome" kidney grills.