I'm trying to plan out my Premium Sound upgrade (from std) and I just want to nail down the whole 2-ohm vs 4-ohm argument so I know what speakers to shop for.

What I've been able to dig up so far:

- According to our XK friends, the sub woofer in the Alpine system is 2-ohm and they were able to verify that by taking a picture of the back of the sub that clearly shows the 2-ohm symbol.
- According to someone over at Roadfly, he tested the impedance on one of his door speakers and got a 4-ohm reading.

What's got me puzzled:

According to the schematics, there are 8 distinct outputs from the Premium amp.
Channel 1- Driver Door Tweeter
Channel 2- Driver Door Mid
Channel 3- Pass Door Tweeter
Channel 4- Pass Door Mid
Channel 5. Rear Door (Driver's side) Tweeter & Mid
Channel 6. Rear Door (Pass' side) Tweeter & Mid
Channel 7. Subwoofer 1
Channel 8. Subwoofer 2

(UNSURE) So if you notice, the rear door speakers get just one input per door that power two speakers and if you know a little about impedance, you'd know that 4-ohm input feeding two speakers become 2-ohm, so a 2-ohm speaker would be needed. The only way I can see Jaguar using 4-ohm speakers is if the amp outputs 8-ohms out of those 2 channels or they use a crossover that filter and split the signal to the tweeters and mids.

(UNSURE) So according to the schematics, there are two channels for the subs on the sedan and the same 2 channels power just one single sub in the estate. Sooooooooo, does this mean the subs in the sedan or 4-ohm and the sub in the estate is 2-ohm? To complicate matters worse, some one here took apart the sub box that comes in the sedan and noticed that while there are two subs, only one was actually powered. Granted he noted that his car was an earlier model that also had the amp in the parcel shelf rather than in the rear trunk, so it could be a different setup all together.

If anyone can chime in with some concrete information or has some of the Alpine speakers around to check the impedance with a multimeter, I'd greatly appreciate it.

 

Maybe the XK uses a different sub?

One of the guys in the S-Type forum here measured 2.5 (DC) ohms resistance on the factory Alpine sub, which indicates an actual impedance of 4 ohms. That one you're thinking of with the amp in an enclosure with only one speaker is a completely different setup, don't worry about it.

I used a pair of 4 ohm kickers in my install, and they put out plenty of bass. I'm glad I didn't go 2 ohm, I'm pretty sure you would eventually cook the OEM amp.


I do notice that the rear door speakers/tweeters in mine are noticeably quieter than the fronts, but I put that down to it's only 80W in the rear, with 160W in the front.

The factory setup doesn't use crossovers, just simple capacitors which function as a high pass filter.

https://www.jaguarforums.com/forum/x...ade-faq-64614/

 

Thanks for the info Combo. I'll post some questions on your install thread.