Hi all, I have a 2004 XK8 with a standard Alpine ICE setup, I’m looking to fit an aftermarket sub and amp, I don’t want to replace the head unit and I’m not planning to replace the speakers at this stage. I have a few questions that I would appreciate some help with.
I have read that the wiring may already exist in the boot for the amp and the sub, however I’ve had a good look in there and can’t see it, has anyone actually found this wiring on a later car, if it isn’t there I plan to run the cables up the centre console into the boot.
I plan to fit the aftermarket Sub in the location where the premium system had one fitted, has anyone purchased one that fitted there and if it wasn’t a perfect fit which I doubt it would be, due to the size, how did they fix it.
I want to fit the amp above the CD player, I plan to make a shelf and fit it into the cage that currently exists, has anyone already done this and if so which amp did they purchase.
Any help with any of these questions would be greatly appreciated

 

I'll help a local lad if i can. Like you i wanted better sound from my standard audio, but didn't want to replace the head unit.
partly for aesthetics but mainly for security.
I mean, who would want to nick it. LOL.
The wiring harness from console to CD rack is omitted on standard system, is as rare as rocking horse poo and is crazy money.
However, it's not needed, and what you're after can be had cheaply.

Under the sub tray there should be 4 connectors, as the jag sub was dual voice coil. (DVC).
Extend these to the CD rack and fit a mono amp with line inputs. I use an Alpine M350, about £40 used on ebay.



Send the line out wires back to the sub.
You can fit an 8 inch and use an adapter ring, or fit a 10 inch and cut 5mm off the panel rim with a pair of tinsnips.
I chose the latter, £20 new on ebay.



You then need to make the subwoofer active by jumping the wires in the arm rest.



You now have great sound at a great price.

 

I did the slightly more complicated job of upgrading the whole system, using the original base-spec headunit. The headunit has line level outputs to a din socket, so you can make a lead that runs to the boot:




I then ran that to a 5 channel Kenwood amp in the boot and used that to drive Pioneer speakers in the doors (2-way composite in the back and 2-way component in the front) plus a Kicker sub in the parcel shelf. I used a ring of MDF between the sub and the parcel shelf to accommodate the slightly different sizes. The car sound way better than when I bought it.