I have just noticed a significant change in the sound quality of my Alpine system in my 2004 XJ8. The sub does not appear to be working. I can go to MODE and select SUB, go completely from 0 to 100% and the sound doesn't change at all.

I was relatively sure it always worked before. Have tried FM, CD and CDC sources and it is the same for each.

Is there a fuse somewhere to check? A reset? Does it have a safety circuit that might have blown?

It is odd. Everything else works. Radio, NAV, display, everything..

Any thoughts? Thanks.

Jeff

 

Sub is still non functioning. Hoping that someone has some experience with this. Thanks for any help.

 

I have observed the same thing, however I discovered it was type of music dependent, some tracks the subwoofer adjustment made no difference while other, very bass heavy tracks had a huge change in bass with sub volume adjustment.

 

just to be on the safe side, switch to rap and try the level again. Then if not you need to make sure you have a signal at the sub...if you do you need a new 1. If not I dont have the wiring diag in front of me but most likely the amp at that point

 

My understanding is that not all XJ's came equipped with a sub despite having an adjustment for it on the head unit. Are you really sure it worked before?

 

Well, some news at least. Had to go back to the dealer for an unrelated issue. Discovered about 4 inches of water under the rear seat. Apparently some seal that was supposed to have been done at the factory was never completed, and caused a sh*tload of water to pool in the well under the back seat.

According to the dealer, the audio system reported that the amp was operational, but the speaker was showing a short. They contend that the cable to the sub was under water and shorting out. However, after removing all the water and rescanning, they say the amp is not working.

They claim there is no external fuse for the sub amp. I find it hard to believe there isn't at least an internal one. And I know that I am not paying the $1,200 they want for a new amp.

I have the Alpine upgraded audio system that is supposed to come with a subwoofer.

I am hoping that a simple fuse replacement would solve this. If not, then a third party amp install will. I think I can see the cones for the sub through the hat shelf screen, but have not torn out the trunk liner to confirm. Would have thought the dealer would have busted me for that one if it was not in place.

Not really sure where to go from here. looks like a new amp. Or at least I'll need to take this one and out and try and repair / replace it.

Any thoughts or history would be nice to hear. Thanks for the input.

 

Aftermarket here i...uh you come......
But better yet, why arent they covering it when a part they claim was not installed at the factory. And what part Ide like to know..even if not under warranty anymore, I would ask about good will since its just now coming to light

 

The dealer did a nice job putting the car back together. Unfortunately, I'll have to pursue a remedy with Jaguar CS. It really was not the dealer's fault. i am trying to find a tsb or service report regarding the absent caulking that I can flaunt over them.

Hopefully I'll get reimbursed for the re-caulking and maybe even a new amp out of it..

We'll see. I'll keep everyone updated.

 

bumping this up. I am having the same problem with my xjr, I have the alpine stereo, but the sub doesn't seem to be working. Where is it located?

 

It's located under the grill on the parcel shelf, which is the panel below the rear screen (glass). The speakers fail, I have not found an aftermarket alternative, and they are in excess of $200. Order by VIN, there is an early and a late sub fitted to the cars. I think the early is HK, the late is Alpine.

 

What size is the speaker?

 

There are/were several listed on ebay. Try googleing xj sub and you will get som hits.