Hello,

I’m looking for the OEM Alpine stereo wiring diagram for my 2002 XJR. I don’t have a PC anymore, so can’t use JTIS at the moment.

I’m planning to add a small subwoofer with a dedicated amplifier in the trunk and would like to locate the OEM subwoofer line-level (low power pre-amplifier RCA level, NOT amplified speaker level) wires and which signals they carry in the trunk. Can anyone help me please?

Also, if there is a plug and play adapter I can use to break out the sub line level signal that would be nice. I can splice into the factory loom, but if I can avoid it I’d prefer to.

Thanks,

Mike

 

So after more searching I think I found what I was looking for on the JagRepair.com - Jaguar Repair Information Resource website.

But now I have other questions. The audio signals appear to be sent over the Ai-net network. Is the line-level signal sent over the Ai-net network via a special signal, or is it a “normal” line-level signal that I can intercept and send to an aftermarket amplifier that I install? Is the OEM amplifier just a standard amplifier, or does it have additional circuitry on the front end to interpret Ai-net traffic and then amplify the audio signals?

I have an Audio Control EQX that I can use to convert the speaker level inputs to line level, but if I can use the signal before the factory amplifier I’d prefer to.

Thanks,

Mike

 

Anyone?

 

The Ai-net left and right channel are just normal line level left and rights, so you can splice into them. The issue is that you have a premium system, so the amp has an Ai-net brain in it that does all sorts of wizardry, like switching between the audio feed from the headunit and the feed from the cd stacker. You'll see this illustrated in the diagrams by the fact it is positioned between the headunit and cd stacker.

You can hack into these cables and feed any signal you like TO the amp, but you can't really pull a signal FROM it.
Somewhere inside the amp will be a combined audio feed, I'm guessing somewhere between an ai-net chip and the actual amplifier section. I'm no electrician, so I'm just going to stop here before I say anything wrong. I'm sure it's possible, but I wouldn't want to start poking around in there without the help of someone who really knows what they're doing.

There is possibly another option, if you don't mind losing the CD stacker you could just pull the audio feed from the headunit Ai-net cable only, and feed this to an amp.

But basically, the short answer is if you want to run an external amp, your best signal is going to come from the amp output, and then run into either a line level converter, or the high level inputs that some amps have.
Don't forget that for your sub there are TWO outputs from the amp, so you'll need to either combine them, or get a sub amp that takes dual inputs.

 

Been there done that, my elegant solution was to use one of the two sub lines to the dual coil unit, replacing it with an Alpine R single, the other line I plugged into a tiny Alpine sub amp installed under the factory unit, this drives 2 bass shaker units under each front seat. (all wiring, door drivers and tweeters uprated to latest Alpine R units)

An old timer Jamaican ICE installer told me once "if you can 'ear it, feel it but still talk over it, you cracked it boi".

I'm happy with my results

 

Thanks for the reply.

I guess I’m confused why I can’t just tap into the cable right before the amp if it carries just line-level signals. Are you saying it’s a 2-way communication there?

I’d prefer not to loose the CD changer, not that I use it now, but if I put a sub in the car I might actually want to listen to something other than FM radio sometimes.

Is there some sort of Ai-net “hub” I can plug inbetween the head unit and amp, or CD changer and amp to “siphon” off a line-level signal via RCA outputs? Guess I’ll start looking for such an animal. I read that the Jag OEM Alpine Ai-net is somehow different than “regular” Alpine Ai-net in aftermarket components. Know anything about that?

My Audio Control will take RCA or speaker-level inputs and convert the signal to line-level then let me bandpass the signal and apply cut or boost at various frequencies, but obviously the sound would be better if I got it before it had been amplified by the factory amp.

I did realize the factory “sub” is dual channel. The amp I plan on running can be bridged combining both channels, or the EQX can combine them to a mono channel. Plus, my subs are dual voice coil, so I have it covered in any of several ways. Thanks for the heads up on that though.

Thanks,

Mike

 

Thanks for the input. I’m going to do more research to see if I can figure out how to take the line-level signal before I give up and use speaker-level, although that is my fallback plan.

Mike