Hi-Fi advice needed :confused:

[Furryballer]

Can anybody help?

A friend is looking to replace a BMW Business headunit with an Alpine CDA-9812 item. But and it seems to be a bit BUT, the car is fitted with the Harman Kardon upgrade system which has a seperate small jack point.

We have been advised that we need to re-wire the speakers back to the head unit, but have seem adaptor lead PX761.

www.caraudiodirect.co.uk/product_info.php?products_id=685&osCsid=b7d85a0f5f4ba3e566bb926605397b94

this the answer to our problem?? Has anybody tried a similar headunit to HK upgrade??

Any help would be appreciated

[off_again]

Sorry, he's got the HK setup and wants to replace it? Nah, lost on me I am afraid. The quality of the components used in BMW stereos is actually quite good. The CD / Tuner kit is quite good, the one thing that it lacks is power (as in Amp). But with a decent amp, like the HK or in my case DSP, its not that much of an issue.

However, that doesnt help - check by removing the headunit itself - see what is wired in the back. Chances are it goes to the Amp (which I assume is in the boot?) and then from there to the rear speakers. So yes, if thats the case then you will need to wire up the rest. But it depends if the headunit has outputs which can be put into the HK amp and on from there - though most manufacturers use different rated speakers to prevent you from doing this.

Like I say, take out the Business unit and see what is wired up - or alternatively leave it to an stereo specialist. BMW's are a nightmare and you can end up spending a fortune to stand still.....

[Furryballer]

He has the HK amp & speakers, which we want to keep, but replace the headunit. Unfortunatly the HK connection to the headunit is seperate to the main connection block.

As you say the quality is pretty good, but he wants the added bonus of MP3 CD playback. He owns such a headunit already.

May well have to go down the professional route!

Edited by Furryballer on Monday 5th June 15:14

[off_again]

What about one of those replacement CD changes (Keg is it?) which looks like a CD changer to the headunit but has all of the benefits of MP3 etc? On the later BMW's its a simple swap over.... might be worth looking at, unless money has already been spent of course.

But, you should be able to output from a headunit to the amp and then from there to the speakers. If not then a separate set of wires to the speakers at the back.

What every you think about this being a pain in the arse - dont get a BMW with DSP!!!! I have and its DVC wired to all the speakers and everything is carried from the headunit to the amp via proprietary coax. Add to that the speakers being non-standard ohms too - well you either stick with DSP or you rip the whole lot out and re-fit everything (at a cost of about £1000...!!!! I guess it seemed a good idea at the time...

[BliarOut]

I'm no expert on the HK stuff, but that particular lead appears to supply a pre-amp input to the car's loom and supplies power to the new head unit. It looks like the Alpine has a low level pre-out output.

www.restricted.alpine-electronics.co.uk/support/ownersdatabase/CDA-9812RR/OM_CDA-9812RR_EN.pdf


You definitely won't need to rewire the speakers if you're retaining the original power amp.