I am writing this guide in addition to my first guide to help others if they want to install a sub box into the Mk7 using a RCA convertor to create pre amps out.
Firstly I will add that this is not a simple job and I would not advise this to be done by a novice. How ever I hope my guide will make it easier for anyone trying to do the same. Also I will add for those that are screamish this does invole taking apart a 3 week old car, but absolutly no damage was done to my new little car.
So here we go.
Take out the front head unit, refer to my FIRST guide to do this. Once you have the head unit out you will have to disconnect two multi blocks from the rear of the unit, disconnect both and remove head unit to a safe place. The smaller multi block is just data cables. The connection you are interested in is the larger multiblock. When you look the block you will see 5 pairs of wires top n bottom plus a single cable on its own. The single cable on its own is the ignition live (only goes live when ignition is on). At the other end of the block you will see two fatter cables, the cable with black on it is the ground, and the other is the permannet live. The other eight cables which are a variety of colours are the speaker cables. The top row is the positive and bottom is negative.
Now take your RCA convertor on it you will have two positive speaker cables and two negative speaker cables. To avoid cutting cables you can push a bare end cable into the back of the multi blocks so push two positive into the top row and two positive into the bottom row. It is not important which speaker connection you use just as long as you use the same for both neg and pos. On your RCA convertor you will also have a positive and negative cable, again push the bare end cable from your RCA convertor into the appropriate neg and pos connection on the multi block. Now with your ampilifier kit you will be supplied with a long blue remote live cable, this cable is pushed into the back of the ignition live cable (the single cable on the multi block), this will mean your amp will on go on when your ignition is on.
Next you will have to feed your RCA cables, (supplied with your amp), your blue remote cable and your power cable to the rear of the car. First tie off your RCA cable and remote cable to something at the head unit so you dont pull them through.
It is fairly easy to feed your RCA cables and your remote cable down from the head unit to the floor. You can then tuck them in behind the carpet, and lead them to the small side panel on the passenger side.
Now you can take your main min 8 gauge power cable and connect it to the battery.
Then this cable can be fed down through a hole next to the washer bottle which will bring it out by the inner arch wheel trim. Thread it round the arch, and by the door hinge you will see some foam sound insulation, this can be moved to the side so the cable can be fed through the hinge to the interior.
Now lift up the rubber waterproof trim and feed 3 cables along it, the power cable the RCA cable and the remote cable, and they will now come out by the rear seats.
It is now possible to pass all 3 cables along the side of the back seat so that they come out in the boot.
Now just when you thought you were done you now have to create an Earth cable, this should be as short as possible and taken from the rear. I used one of the 13mm bolts that hold seat belt mounting in. Simple take out bolt connect your earth cable and put bolt back in.
Now the fun bit connect all those cable up to your amp. I am using a active sub, meaning the amp is bulit into the sub box. To test it temporarily reconnect the front head unit and dash and power it up to see if it all works, (remember to turn on your ignition).
It should all now come on. With me it all worked first time, I was very pround of myself.
You can now put the car carefully back together. I did this whole job without a single scratch and no damage to the car at all, the entire system could be taken out without any sign that had been there.
I hope this guide has been of some use. Any questions then please ask.