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
It is the same, standard HiFi-System (option 676), HIS4... it is even the same as in the 128i.