[musicman]

I wanted to replace the Boost-HeadUnit with an Alpine 7894RB Headunit but ran into a lot of problems. Although the Alpine could be installed and received power and antenna feed, the HK amplifier refused to turn on.

I've found a possible solution for this problem on a German internet site.

To solve the problem with the HK-amplifier you should directly connect the HK-amplifier to the speaker outputs of your new Headunit. A "High-in" is absolutely necessary.

Does anyone have any experience on this matter?

[GTT 280]

What is the point in just changing the head unit ?
Your not going to improve the performance of your system as the amplifier will control volume output and clipping of the speakers. All you'll achieve is the loss of extra K-bus functionality (eg. DSP setting etc.) and you'll gain some flashing lights which will be more appealing to theives and won't match your cars interior.

Mmmmm - interesting justification...

[musicman]

I know understand why BMW gives so little information on the HK-system: it is terrible.

Unfortunately, I based myself on the reputation of the HARMAN products and ordered the HK-system in my MCS: big mistake.

The Boost Head-Unit absolutely sucks, and is in now way theft-proof, since you can't remove the front.

The Alpine Head-Unit has full DSP capabilities which can match the DSP of the HK system. It also has MP3 compatibility and a DAB (XM in USA) controller. You can detach the front of the Alpine Head-Unit, so theft is less likely than is the case with the Boost Head-Unit.

The front of the Alpine Head-Unit is aluminium and therefore compatible with the aluminium look of my dashboard.

I'm stuck with the HK system and have at the moment no ambition to remove the complete system (amp and speakers).

[laz]

i think just change your exhaust .. then you'll be too busy listening to it you wont worry about the HK .. its not that bad ..