After the accident that burnt out the audio amplifier in our Range Rover I decided to see how difficult it would be to replace the factory amplifier with a standard audio car amplifier.

The only original issue was that the amplifier has a connector for a databus (BMW's iBus interface) which is not standard in any amplifier I could find in any normal shop, so I decided to do some test. Armed with a iPod, and standard car audio amplifier from Maplin (A Nikkar 4 channel power amplifier) I started sorting out the wiring harness. Maplin even provides the handbook online as a pdf.

Working from the theory that the thicker cables were for the bass loudspeakers I worked my way through the twisted pairs.

The first lead I figured out the purpose of was a lone (non-paired) white cable - this was the soft-start cable that turns on the amplifier after a time-delay of 2 seconds to avoid the “Thump” when the raid is turned on.

Power was easy - it was the RedGreen and Brown pair - where Brown is ground.

The amplifier now turned on and off when the radio was turned on and off.

Using the iPod to supply signal to the amplifier the rest was easy, but took a bit of time.

The cables tuned out to be :

U = Blue

N = Brown

So I will need 2 times 4-channel amplifiers, as each of these amplifiers has a built-in crossover, i.e. feeding the bass and mid/high loudspeakers separately.

I decided to split out the tweeters in the front using a standard passive crossover.

The SubBass is fed indirectly from the sum of all the bass speakers, and does not therefore require separate cabling.

The mess in the back now looks like this (with one of the amplifiers wired in).

So in the end I have not been able to figure out what the connection to the iBus does - as it does not seem to have any easily discernible function, and the car stereo now seems to work ok.

Next - how to install the second amplifier to use separate amplifiers for the bass and mid-range speakers.

Technorati Tags: Ramblings

Technorati Tags: