I gave up on the HK alpine - I wanted to get bt connectivity. Because of the nature of the HK, I set up from scratch - leaving the HK system in (excepting main speakers) and replaced the main speakers with some decent multiways which went straight into the HK speaker mounts and running new wires from the head units to each door. I could add a ub at some point, but the setup I have is plenty good enough at the moment (it goes loud enough to mask the squeaks, knocks and rattles so I can pretend they're not there!).
I have lost my steering wheel controls, which is annoying, but the head unit is mounted above the Hevac, so not too much of a stretch for volume and source. WOuld be nice to have them back so might pm clarkey too
Dave - I've still got my dsp in the boot, not being used. Might not be able to get it out for a couple of weeks or so, but happy to lend if you're in need.....