I feel compelled to post this here since a gaggle of questions are bound to be asked about sound system options in the M2.
First thing to realize: In the U.S.,
the Harman Kardon sound system on the M2 is exactly the same as the optional HK sound system in any other 2 Series. There are absolutely no differences.
In light of this, if you want or need information about the system, please familiarize yourself with the content in
this subforum on the 2Addicts forum. You'll discover that the issues with the 2 Series HK system are many, and that upgrading it is immensely beneficial, relatively inexpensive, and fairly straightforward in most cases.
Good luck, everyone. Hope this knowledge (base) helps.