Originally Posted by HIS4
The base hi-fi audio system in the M3 is not the same as the 328. I suggest the OP go to the Audio forum. There has been numerous threads about this discussed in detail. Nobody can tell you if it's good enough for your taste or not but there is very detailed information about the response characteristics of both the base hi-fi system and the enhanced premium system
I searched but wasnt able to find much info.
There are few who say the base M3 stereo is the same 10 speaker system found in the base 328i.
Then theres others who say its the same speaker setup but has more power going to them in the M3.