Dominic, anything to add, you were there after all!?

I want an Audi TT? :-)

A bit more technical background, in case anyone else ends up with a TT to put a system into:-

To original TT system uses the A3 active system, with the front speakers powered directly off the OE unit, and an amplifier (with odd input level) on the rear speakers. We connected the RCA output onto the Empeg using a vehicle specific adaptor (Autoleads PC9404), and installed a kicker iX402 amplifier below the first aid kit in the rear 1/4 panel. There's just enough space to squeeze the amp chassis in widthways, but it's in a relatively large cavity, with good air circulation, so cooling shouldn't be too much of an issue.

With just the OE amp connected, system noise was all but non-existant. Once the 402 was connected up though, we had major interference problems - a really loud alternator whine at probably 9/10 the main system volume. To get around this, we had to tie the original amp's signal ground down to the Empeg's mounting cage, along with the Empeg's own earth. We then ran an 8AWG ground from the same point down to chassis ground in the front of the car. The 402 power ground was then run down from the back of the vehicle to the same point. This got rid of most of the noise, and we killed the last traces by grounding the 402's RCA ground cable to an earthing point in the rear 1/4.

As Paul says, the whole job was pretty labour intensive - I didn't actually spend the whole day working on the car, as there just wasn't the room for 2 of us to work on it most of the time, but it must still have taken 10hrs+. The biggest problem for us was probably the car's build quality. It's so well put together, it's really time consuming just to disassemble things - and we had to take a fair amount of trim out to run cables, etc.

I had hoped to get some decent pics of the whole process, but in the end all I got was a couple of very hastily snapped digital pictures towards the end. If I get a chance, I'll put 'em up online sometime.

If anyone does end up putting a system into an Audi with OE active system anytime, feel free to mail me - we do a lot of work on Audis anyway, so tend to have a pretty good idea what to do with them these days.

Dominic



Cambridge Car Audio
http://www.cambscaraudio.co.uk