MINI HK with aftermarket head unit – productionized!

Posted on by Ian C.

Long term readers will know of my terrible experiences with trying to upgrade GBMINIs stereo at Tweeter, and of my eventual solution to run an aftermarket (Kenwood) head unit with the Harmon Kardon amp & speakers. Originally I had the stock radio in the boot, connected to the HK amp, because the amp requires digital messages from the stock head unit to control volume, tone, and sound mode.
More recently I adapted one of my companies products to persuade the HK amp to run.

Now, after interest from MikeyTheMini who sells audio parts for the MINI (and other cars), I decided to make a “production version” which I have called the “HKenabler”; I plan to “pot” the HKenabler in a little box, with just the wires coming out – for maximum protection:

HKenabler circuit
Potting shell for HKenabler

This circuit connects to the car using the same adaptor harness sold by MikeyTheMini and used to connect the aftermarket head unit. Three wires (+, – and iBus) go from the car to the HKenabler – the + is the same + that turns on the HK amp, and comes from the “amp out” signal of the aftermarket HU.
When power is applied to the HKenabler, it communicates with the HK amp and instructs it to run with neutral balance, bass, treble, fade and a fixed almost full volume. Then the aftermarket HU volume control adjusts the overall sound level.

My experience and that of MikeyTheMini’s one test is that the HKenabler can get more volume out of the HK amp, and of course you benefit from the better features of the aftermarket head unit.

An optional extra two wires from the HKenabler allow a switch to be installed in the car which controls the sound mode of the HK amp (MINI H/K, SPATIAL, ELECTRONIC, INSTRUMENTAL, FESTIVAL); you can also control the “DRIVER MODE”. Even with no display you can easily recognize the “hollow” INSTRUMENTAL mode and the echoing FESTIVAL mode, so it is easy to figure what selection you have – or just choose the one that sounds best!

If anyone with the Harmon Kardon system is interested in replacing their head unit but keeping the amp and speakers, you can contact me or MikeyTheMini to learn more.

Running Harmon Kardon with no factory head unit

Posted on by Ian C.

As some will know, I have installed an aftermarket Kenwood head unit connected to a 20GB MP3 Kenwood Keg.

I had planned to replace the Harmon Kardon amplifier & speakers with aftermarket, but after a lot of pain & grief with Tweeter, I was left with an aftermarket head unit and factory amp – but the Harmon Kardon amp will only work when connected to a factory head unit, so I had to keep it installed:

This install lasted a while, then “scooterboy” provided me with a factory head unit which I was able to strip down to a minimum – enough to still run the Harmon Kardon amp, but “hideable”:

MINI stereo, stripped down

 

While this system worked, it remained awkward. With a volume control on the Harmon Kardon amp (controlled by the steering wheel remotes via the stripped down factory head unit) and a second volume control on the Kenwood head unit, it was confusing for other people (sorry Keith!)
I tried setting the Kenwood to a fixed high level and using the steering controls only to adjust volume, but then I lost the “loudness” low volume emphasis function of the Kenwood.
I could not set the Harmon Kardon to a fixed high level, since the factory head unit always reverts to a medium volume when it is turned off/on. So for a while I would start the car, use the steering controls to increase the Harmon Kardon level to maximum, then use the Kenwood volume control the rest of the time. One problem with this was losing the speed compensation of the Harmon Kardon amp, which does not work when its volume is already at max.

Continue reading Running Harmon Kardon with no factory head unit

Stripped Head unit from “Scooterboy”

Posted on by Ian C.

I have been stripping down the head unit that “scooterboy” gave me; even though it is March 2002 manufacture, it worked perfectly with the Harmon Kardon amplifier, allowing me to adjust the volume, mode, etc.
I stripped various parts off it, step by step, checking that it still worked: casing, CD player, rear connector, radio module … until I was left with this, which still runs the HK amplifier:

MINI stereo, stripped down

Hopefully I can find somewhere to stash this within the car … at least till I get around to making something even smaller!
Thanks Scott 🙂