I didn't know that, but now you have mentioned it I think I can see a couple of bolts in the photo, just in front of the cross member.
Video Building a Sub Box for BMW Z3
- Thread starter Low Rider
- Start date
Grandparipper
Regular Member
The HK system uses a weird impedance for everything. I was told by experts that you could run into problems hooking up typical aftermarket speakers to the HK setup. If you compare the size of their little tiny amplifiers that they say are producing 30 watts per channel times six channels to a typical 'real' aftermarket two channel amp of 30 watts, you will see that someone is using 'alternative facts'. One solution is to use an aftermarket subwoofer amp that can run off of line signal inputs, which means speaker leads. Beware that the impedance could still be an issue.
My solution was to gut the whole system and sell it, then replace it with 'real' stuff that works and can be added on to. I replaced the main drivers with 6.5" Infinity separates, which meant yanking the door panels to put the tweeters in the factory location. This was tricky and I busted a couple of panel fasteners which repaired with epoxy. I skipped the back speakers entirely, which may not be the best room filling sound solution, and built a sub box with an 8" driver. I put in a good quality four channel amp using the factory bracket modified a bit in the trunk and routed long RCA cables to it and a new fused power source directly to the battery. Every sub you look at can come with different impedances for installation flexibility, but typically are 4 ohms.
The result is clean clear sound and no smoke. I posted pictures of my sub build earlier.
My solution was to gut the whole system and sell it, then replace it with 'real' stuff that works and can be added on to. I replaced the main drivers with 6.5" Infinity separates, which meant yanking the door panels to put the tweeters in the factory location. This was tricky and I busted a couple of panel fasteners which repaired with epoxy. I skipped the back speakers entirely, which may not be the best room filling sound solution, and built a sub box with an 8" driver. I put in a good quality four channel amp using the factory bracket modified a bit in the trunk and routed long RCA cables to it and a new fused power source directly to the battery. Every sub you look at can come with different impedances for installation flexibility, but typically are 4 ohms.
The result is clean clear sound and no smoke. I posted pictures of my sub build earlier.