I’m looking to install subwoofers in my 2012 jaguar xj supercharged. All I need to do is tap into the correct speaker wires from the stock amp. Does anyone know witch ones are the best to tap?

 

Deegan, let me look at the diagrams and figure out which wires you will want to tap into. With that being said, what you are wanting and potential consequences are vastly apart. I used to do a lot with car stereos and unless you plan on putting in a bunch of passive cross overs, you run a high chance of overloading the amplifier section and that will result in the loss of those channels (ie, reduced volume because no power is going to those speakers). The other option is to use line level inputs to a separate amplifier to then power the subs with the new amp. Let me see what the options are. By the way, can you tell me the number of speaker setup you have. That way I can make sure I am looking at the correct diagrams as there are 2 different stereo setups as I recall for your year car.

 

X351Deegan, let me state first that if you do not follow exactly what I say, DAMAGE WILL RESULT!!!!!!!!! This damage will most likely result in the loss of atleast part, if not all of your amplifier for the car. I am putting that out there just so we are clear. I know how people want to get "something for nothing" and I will tell you right now that this system has been maximized and the odds of you getting the "something for nothing" is not going to happen. Based on your wiring, I can tell you that you have a left hand drive X351, 15 speaker set up. This amp already has the frequencies broken out. So, you cannot tap into other wires from what I list and get the range of frequencies that you are after for your subwoofers. If you get any, it will be a very limited range of them.

Lets start with the plug in question is the blue plug on your amp that you show. This is known as the "C4ME22E" plug. This plug has the wires that you are after. If you look on the plug, there are numbers next to the wires. These refer to the pins inside the plug that the wires are attached to and will be what I am referring to from here out.

For subwoofer A, you are looking at Pins 3 (+) and 11 (-). Pin 3 is a green wire with a violet stripe. Pin 11 is a gray wire.
For subwoofer B, you are looking at Pins 4 (+) and 12 (-). Pin 4 is a violet wire. Pin 12 is a yellow wire.

WIth the mention of the subwoofers, if you have them in the car and wired up, DO NOT!!!!!! wire a new speaker in parallel to the factory one. YOU WILL DAMAGE THE AMPLIFIER!!!!!!! The best you can do is tap off of these wires and run the new wires over to a line in input to an amp with the power that you are desiring. You may be able to get a few dB of bass gain by going with a low power (around 300 watt peak) subwoofer that has a high dB/watt rating that is the same size as the factory subwoofers. This will net you more overall sound. HOw the new speakers are going to sound with the high end speakers that are in the car is now the big question.

This information should answer most of your questions. If you have more, please ask. I know this amp has been pushed to its limits and any change comes at a potential cost of damaging the amp. Hence my cautions. If you think you know better, please prove me wrong at your own expense. I used to do car stereo install and have worked with electronics most of my life (35+ years).