The trouble here is there is no standard nomenclature.
All BMW systems are made by the Harmon Becker company sometimes
the HK label appears on the tweeter housing.
There are three common systems for the e9x series plus the EPS which is rare. (has a bigger amp and even more speakers is
a 2000 dollar option )
The common systems are the stereo , Hi Fi and Top Hi Fi.
The top hi fi is (the L7) sometimes referred to as the HK .
So you need to identify which system you have in terms the other members
on this board can understand. Since the Top Hi Fi is the one that
people
like to adjust that has more than bass treble,balance and fader that is the
only one you are likely to find adjustments on .
Please use the following pdf to identify your system.
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/showthread.php?t=352586
I had an e46 with the Harman Kardon sticker on the tweeters.