[Distinct]

I have the non HK stereo and it's pretty weak and lack high-end clarity, most obviously from the lack of head directed tweeters. Right now there's no speaker there in the a pillar door. Has anyone ever added speakers? I see some upgrade kits but I don't quite understand how it comes with the speakers there when my car doesn't have the speaker housing to begin with.

[Abrunho]

I’ve added both the Harman Kardon tweeters (the HK triangle/ enclosure reference already includes the tweeters and wiring) and the HK midrange units (which include matching plugs for the tweeters), plus metal grills to my M2C from day one, all installed at the BMW dealer. I didn’t want the HK speaker in the middle of the dash, so I configured the car with the basic sound system and went this route…
It’s all plug and play, although the installation required removing the door cards; all parts are still available (you can check the correct references at a dealer or online), they work fine with the stock amp and you don’t get any codes. Sound is OK by my (not overly demanding) standards.

[Kikuchiyo]

I did it by myself. You need a pair of tweeters and tweeter housings and replace factory triangular parts with them.
In addition you need a pair of Y-shaped wiring which divides the audio signal to midrange speakers and tweeters. An OEM HK midrange speaker has a dedicated jack where a cable of a tweeter is plugged into. On the other hand, OEM non-HK one doesn’t have the jack, therefore you need such bifurcation cable in order to provide audio signal to a tweeter. As it is not an OEM part, you need find it somewhere or otherwise you need to divide the wiring using electrotap. It is not bad but ad I wished my car kept intact I went that way.

[chris719]

Originally Posted by Distinct

I have the non HK stereo and it's pretty weak and lack high-end clarity, most obviously from the lack of head directed tweeters. Right now there's no speaker there in the a pillar door. Has anyone ever added speakers? I see some upgrade kits but I don't quite understand how it comes with the speakers there when my car doesn't have the speaker housing to begin with.

To do it correctly you need to replace the amp. The best thing to do is skip the HK amp and go with aftermarket drop in MATCH UP7 BMW or UP8.

[Maynard]

I've heard that you can dramatically improve the sound just by unhooking the center dash speaker - super simple and free. And on the F22 board there is a lot of info on retrofitting tweeters (simplest to just use factory housings, aftermarket speakers and crossovers). I think you can get nearly equivalent benefits from a coax speaker if you don't want the hassle of fitting them.