This is the complete story of my post originally started here - https://www.jaguarforums.com/forum/x...adunit-173928/ - and placed onto a separate post to make the information easier to find.

I purchased a 1997 XK8 convertible with the Harman Kardon stereo upgrade, which wasn't performing well, and this post documents my experience with repairing and upgrading the system. Although I contemplated changing the head unit and the entire system, I eventually gave in to my desire to maintain the stock in-dash appearance and focused on doing speaker work and adding Bluetooth capability. When I pulled out the speakers, I found that the door speakers were fine, the dash speakers were shot (foam edges) and the former owner had replaced the subs in the rear with 2-way standard speakers. Since the crossover is in the amp, these speakers basically put out little volume and distorted when the volume was up. That, plus the buzzing of dash speakers, probably accounts for much of my dissatisfaction with the sound quality. After reading previous posts, I found a couple reasonable options for purchasing new subs. The Kickers described in older posts are no longer available, but I spoke with their tech. support, and they recommended using the updated version, which is the Kicker CompRT 43CWRT672. This speaker has dual 2-ohm coils, which I'm going to wire in series to get a 4-ohm load. I never found anything definitive on whether the subs that came with the car were 2 or 4-ohm, and since I don't have the originals, there is no way for me to test them. Based on other posts of people who used the 4-ohm Kicker (older models), I'm going with 4-ohms in my setup. Better to give up a bit of volume vs risking frying the amp.

Another interesting find. In the HK subwoofer boxes, I found another 2.5" tweeter, identical in appearance to the dash speakers and measuring 4 ohms, behind the cloth screen in the upper corner. I had thought this might have been a bass port, but the presence of two wire pairs connecting to the box had me questioning whether there was another speaker in the box or whether the connectors were bringing in a signal and sending out a signal to another speaker set elsewhere in the car. So, it turns out that there are two speakers in the box, a sub and a mid, connecting to these wires. I might have figured this out if I had seen the correct wiring diagram at the time and compared the wire colors, but it turns out to not have mattered because the 2.5" mids' foam edges had disintegrated. That means the ones in the dash didn't just fail because they were under the windshield in a high heat location. FYI, taking the box apart to get to the mid speaker inside, which is mounted from the rear (inside of the box) is difficult. BE CAREFUL not to break the brittle plastic around the box mounting holes. I cracked one with light pressure when trying to pry the face of the box off. After removing the screws, it is necessary to pry the plate off gently to pull the plate away from the sticky rubber gasket that seals the plate to the box. If you're careful, you can salvage the gasket for reuse when you reassemble the box (edit: salvaging the gasket isn't a good idea, as per later post below).

Dash speakers, which other posts reported as mid-range in the 3-way component setup with the door speakers, the same 2.5-inch mid-range speakers as are in the sub box aren't easy to find. A local speaker repair shop told me that they couldn't find a suitable replacement foam edge to fix the factory speakers, so repairing the originals wasn't an option. I'm currently considering a Jeep/Mopar speaker that's still available, but is marked as a tweeter-mid vs. only mid. Can't find spec's on that speaker, but I may just end up trying it. The physical appearance is similar to the Jag LJA4140. Mopar part number for the replacement is 56038612AA, but I have no idea what the frequency response is...makes me nervous that they market it as a tweeter, but if there's no capacitor on it limiting frequency response, it would seem to be suitable for a mid range function.

For Bluetooth, I came up with a very good option that utilizes the CD plug in the radio yet maintains the CD functionality. The unit has a mic-button functionality to activate Siri or Google Voice built into the mic, and there is an add-on option to split the button from the mic to allow positioning the mic in a different location from the button. The unit is sold by Discount Car Stereo and is the JAGCD-HF model. This is marketed for 98 and after model years with the Alpine system, but their tech. support advised that they can modify it to work with the HK system in a 1997 model upon request. The unit with the mic/button split option was about $200, but I thought that's a reasonable price to pay to get BT phone and audio input without using a cassette or antenna adapter. They do have less expensive options if you're willing to give up the CD changer or will accept using an antenna adapter to input the BT signal vs. hard wired to the unit.

At the moment, I'm waiting on the subs to arrive, am still looking for dash speakers, and am still waiting for the BT equipment to arrive.

I'll put up a post once I get this all done to provide the project results. Only fair considering how much useful info I've harvested from the forum...repairing visor mirrors, replacing the HomeLink with a unit to do rotating codes, repairing fabric separations in pillars due to foam rot, car disassembly procedures, wiring diagrams! I'd have been totally in the dark without all of the advice posted here.

 

OK, here's where I ended up. The Kicker CompRT43CWRT672 speakers wired in series to get 4 ohms out of the two 2 ohm voice coils worked fine (EDIT: well, not exactly...see post below). For the two 2 1/2" dash speakers and the two 2 1/2" identical mid-range speakers in the sub boxes, I ended up buying speakers that were specified as 2 3/4", which are the size used in Jeep and Chrysler applications and some other models. I wondered whether the brand specific Jeep/Chrysler speakers may have had a capacitor on the speaker to limit functionality to a tweeter, which is how they specify the speaker, so I continued to search for a speaker that didn't have a tweeter specification since the Jag speakers are used as mid-range. I couldn't find any detailed specifications for the 2 3/4" speakers that I found online (Memphis PRX-27), but I was able to find a local stereo shop that had them in stock, allowing me to see them in person before buying. FYI, there is also a PowerBass S-275-C speaker online that has a similar appearance and size, but I never looked at these beyond finding them online.

The PRX-27 speaker diameter is identical to the stock speaker, but the metal frame is larger than what will fit into the XK8 in any of the locations (hence the 2 3/4" vs 2 1/2" size...it's not the speaker itself that's different, it's the frame). The magnet is slightly larger/deeper, but that wasn't an issue in the sub boxes. With the dash speakers, you have to be careful to get the top ring/cover well up into the speaker grille, or the magnet will hit the dash below and will keep the speaker from setting all the way down, causing the grille to sit too high. Note that the Memphis speaker doesn't come with a top ring & speaker cloth cover, but I was easily able to remove these from the factory LJA4140 speakers and glue them onto the new ones. The plastic rings are the same size, but I did have to grind the ones for the dash mount slightly using a bench grinder to get them fully into the grille. To trim the metal frames, I first tried the grinding wheel after marking the factory speaker's outline...quickly realized that this was a bad idea because the metal shavings stick to the magnet and the speaker frame. Next, I tried a pair of tin snips following a scribed line on the Memphis speaker made by holding the old over new and scratching the outline. That worked fine. Be careful to note that when you lay the old speaker over the new one, the alignment notch next to one of the mounting holes will be reversed, so don't mark/cut that initially. Cut the basic outline first, then flip the speakers, set them side-by-side facing up, and visibly match the notch cut.

One other important point is wiring. The factory speakers aren't marked + and -, so you have to figure out which is which. Fortunately, I eventually found the factory wiring diagram for the Harman Kardon premium stereo installation in another post, including the color coding, and I was able to determine that black wires are ground - and "black with white stripe" wires are + on all speakers. That, by the way, helped me to realize another issue with what the previous owner had installed to replace the subwoofers. The installer wired them in reverse phase...hence the little bass that I might have gotten from the 2-way speakers was essentially non-existent.

The end result of my installation sounds great to me (EDIT: see post below for my subwoofer reconsideration). For the record, I'm not an audiophile. I wanted a good stereo for weekend cruising. I wasn't looking for a multi-thousand overhaul of the head unit, amp and speakers. My assumption is that a $75,000 Jag with an $1,800 radio upgrade in 1997 must have had a reasonably good sound system if it were working correctly with factory-equivalent speakers, and I was correct. I can crank this system and get a reasonable amount of bass and clean, crisp highs without distortion. Perfect for what I wanted, and I was only out about $300 for replacement speakers, a bunch of research time, and a job that, now that I know what to order and the necessary modifications to cut the mid-speaker frames, could have been completed in about half a day. Photos attached. Hope this helps someone facing a similar challenge in the future.

In a couple weeks, I'll pull the console to add the JAGCD-HF Bluetooth adapter and see how that works. Will post an update when done.

 

I went thru all of the same problems with my 97 XK8 HK system.
First the speakers are 4 OHM. Mine still had all of the stickers and markings legible and they state 4 OHM.
I had mine repaired at Orange County Speaker in southern California. Including my 2.5 inch speakers. They have since changed names but still offer the same high quality. My were repaired over 3 years ago.
This is a link to there new web site: Home

 

After living with the updated system for a week, I decided that the bass coming from the replacement subs wasn't sufficient for my taste, particularly with the top down, so I decided to look into getting more bass out of the subs that I purchased, Kicker CompRT 43CWRT672. In reviewing the specifications for these, mounted in sealed subwoofer enclosures, I saw that the recommended operating power is in the range of 150 watts RMS each (300 for the pair). With the factory amp reportedly rated at 240 watts total for 8 speakers, it was pretty clear that the subs weren't being sufficiently powered. At the recommendation of Kicker technical support, I purchased a Kicker 43CXA3001 300 watt amp to put on the subwoofer channel. I had contemplated a 2-channel amp since the original subs were on separate left and right channels, but Kicker support recommended against that, stating that I'd get better performance out of a single amp channel and that left/right balance on the sub channel isn't really necessary (which made some sense because the coupe XK8 only has one center mounted sub).

Wiring for the amp wasn't very complicated, but working in the trunk with the original wiring was a bit challenging since there isn't much play in the original connector wiring. The rear sub speakers are factory wired directly to the amp on separate wire pairs, and these were easily identified at the connector using the wiring diagram above. I don't know the original wire gauge that was used, but it appeared to be in the 18 gauge range. Regardless, with 300 watts available to two small subs, power loss in the speaker wire really wasn't a concern. The speaker would still be more than sufficiently powered, and there didn't seem to be any real advantage to running new speaker wires vs using the factory wiring. To connect the amp, I removed the harness clip going into the amp (the larger one), clipped the sub channel wires, connected the wires from the factory amp connector (amp out) to the new amp inputs using RCA connectors (soldered on and being careful to match the factory + wire to the amp + input to maintain polarity), and connected the wires going into the harness to the new amp speaker connectors (again, being careful to maintain + polarity). The new amp was supposed to be able to handle high-power (speaker level) inputs using a switch on the amp, but when I initially tried this arrangement, I noticed some "clipping" distortion with the subs. A tech at Kicker tech support suggested using a "line output adapter" to drop the power going into the amp, and I purchased a Metra unit that was available locally. Kicker also makes these, and they start at around $15 and go over $100. I opted for the $15 version, which is supposed to handle about 50 watts, and I'm guessing that the factory amp input won't exceed that. If it does, I guess it will eventually burn out the adapter, and I'll have to get a better one. Putting the line output adapter in simply involved inserting it between the factory amp output connector and the new amp input. I also had to add a power sensing line to turn on the new amp at this point because, while it was able to automatically turn on when the speaker-level inputs were used based on signal sensing, that feature doesn't work with the low-level input source. To get the amp to power on with the radio, I attached the power sensing terminal on the new amp to the power antenna wire, which was easily accessible on the same connector I was working with behind the factory amp (on my car Light Green & Black per the factory wiring diagram).

When all of this was done, I had expected great results...I was wrong. The subs had terrible distortion, and I tried a variety of amp settings with no luck in getting rid of it. Kicker tech support tried to help, but couldn't identify the problem. To narrow it down, I plugged my cell phone into the amp and played that as a source to eliminate the question of whether the distortion was sourced with the car system or the speakers themselves. Same distortion, so I knew it was a speaker issue. Eventually, with the assistance of a local technician at a stereo install shop who helped me bench test the speakers/enclosures with an amplified source completely separate from the car, the problem was identified. When I re-attached the face to the sub enclosure after replacing the mid-range speakers, I had used the original, but slightly damaged, gasket. With 10 screws, you'd think that it would have sealed OK, but that wasn't the case. The gasket was leaking in a couple spots, and by pushing on the speaker, you could hear the air whistling through the joint, apparently vibrating the gasket and causing what sounded like distortion.

I ended up disassembling both enclosures again, using a tack caulking material (I didn't want to use anything permanent because it's possible that the mids might have to be replace again one day), and tried to make sure that that all joints would be airtight. I also glued the wire connectors onto the enclosure to ensure that they wouldn't vibrate with the increased bass. Although there was still some minor leakage when I got done, it wasn't enough to cause any dissatisfaction with the result. The amount of bass that the new arrangement puts out is very satisfying...INCREDIBLY better than what I started with putting these subs on the factory amp. And, the factory amp/speakers for the rest of the system work fine.

It was also recommended that I use the remote level control, which is an optional plug-in for the new amp and allows you to vary the level of bass depending on what you're listening to, convertible top up/down, etc. I took that advice, which required running a single wire from the trunk to the dash, and it was well worth the effort. Varying the level of bass is a very nice option to have. To run the wire, I had to drill a hole behind the passenger side sub enclosure next to the original wiring harness penetration between the back seat and the trunk because I couldn't successfully get a wire through the original penetration to the side of the gas tank and into the trunk.

Here are some photos of the enclosure, the tack caulk that I used, and the final installation. Next project will be adding the bluetooth adapter, but I'm going to enjoy driving the car for a bit now that it's put back together before I tear into the console removal project.

line output adapter behind factory amp
amp installation (I used a plastic backer to screw into behind the panel for stability)
rope tack caulk applied to the joint between the face and the back of the box (smoothed and pressed down using wax paper)
rope tack caulk
original gasket material (allowed air leakage around screw holes, and not reusable if damaged at all during opening of enclosure)
A good place to start separating the face from the box (be careful not to pry hard and risk damaging the plastic...patience)

 

Wow. Super.

 

Any update on the bluetooth installation?

 

Jlk, I hope I'm not stepping on onfire's toes but wanted to offer help since I use the same jagcd-hd unit. I love it! Never would have thought it would sound as good as the CD changer but it sounds better, much better.

what questions do you have about it?

John

 

Welcome to the forum jlk,

I've reduced your entire QUOTE of OnFire's post #4 to the relevant section referenced by your question. Please do NOT QUOTE massive posts in full. It's very tedious for everyone reading the thread to wade through the same repeated content.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Thanks to John for answering with his experience. I had ambitious plans, but summer came to Texas before I got a chance to pull the console. Lacking an air conditioned garage, I still haven't put it in. It's on the list for my first project after a cold front comes in this fall, along with mounting the USB charging port, the bass level know, changing out some bulbs in the console and putting in a rear window switch...all of which are tied to having the console come out. I'll post the results when done.

 

Thanks. A friend has a 2002 Vanden Plas with 11000 miles on it. I'm hoping to buy it from him in the next few years. If I do, I would like to have bluetooth capability for phone calls.

 

Van Dan plas is an XJ model right? Dont forget we are XK8 XKR forum here.

 

Quick update...I'm finally about done installing the Bluetooth module and reassembling. Will post details and photos when complete.

 

IF YOU RESPOND TO THIS POST, PLEASE BE SURE TO NOT QUOTE THE ENTIRE POST IN YOUR REPLY SO THAT THE PHOTOS AREN'T DUPLICATED IN THE REPLY.

Here's the final report, more than a year after I started working on this project. The short story is that the system sounds incredible and has all of the capabilities I was hoping to end up with. Even with the top down, my XK8 sounds like a mobile performing arts center. The subwoofers that were added with the amp and the bass control give a lot of punch, and standard speakers on the factory radio head and amp produce great audio on CD, radio, tape and Bluetooth (BT) sources.

BLUETOOTH EQUIPMENT: As noted in my original post above, I found a Bluetooth option that utilizes the CD plug in the radio yet maintains the CD functionality. The unit has a mic-button functionality to activate Siri or Google Voice built into the mic, and there is an add-on option to split the button from the mic to allow positioning the mic in a different location from the button. The unit is sold by Discount Car Stereo and is the JAGCD-HF model. It is marketed for 98 and after model years with the Alpine system, but they modified it to work with the HK system in my 1997. My adapter, including a separate microphone and activation button option (the basic unit comes with a combination mic/button) was about $200.

INSTALLATION: Installing the BT adapter required removal of the console, and while I had that apart, I took advantage of the opportunity to fix a burned out bulb in the A/C display and installed a new rear view mirror with a DVR forward camera and backup camera. I'll write separate posts on those projects so as not to get them mixed up with the stereo story.

Removal of the console is pretty easy, and there are a few YouTube videos talking about that procedure. However, I will add a few notes of caution and supplemental info for those who are going to give this a try. First, a number of plastic pieces were cracked or completely broken and required repair or replacement to reassemble the car. Be prepared to deal with this since your car is old. In my case, the plastic piece under the storage box latch had completely broken, and the plastic frame around the A/C-Radio unit that pulls out was cracked and partially broken around a few screws. To shore up the cracked plastic pieces, I cut some thin sheet metal and glued it with epoxy to the underside of cracked areas to prevent any future transfer of stress to the cracked plastic. Where pieces had broken to the point of not being repairable, I used an epoxy putty stick (Harbor Freight $5) to form what had broken off. That stuff is great for making replacement pieces...strong and easily cut/ground into shape after it hardens (which is pretty fast).

Connecting the BT module was also strightforward. It plugs into the line connecting to the CD changer and outputs to the place where the line was disconnected. Power is available from the radio harness (found with a 12v probe). DO NOT USE the trailer-type connection adapters that snap over the wire, as they don't make reliable connections. Strip and solder the power lead to avoid having to remove everything because power is intermittent or goes out entirely. The ground can be connected to the ground lug on the back of the radio.

LESSONS LEARNED: (1) Check everything before reassembly. In my case, it turned out that the wiring harness provided with the BT module was an incorrect part. I plugged everything up and tested everything but the remote mic before reassembling (what could go wrong with a simple plug in mic?). Turned out that the adapter for the remote mic was not compatible with my module. Should have tested EVERYTHING before I reinstalled. Oh well, I was getting pretty good at removal and replacement of parts by this point. I'll mention that the staff at Discount Car Stereo was really exceptional to work with when I found that I was having problems getting things to work. It's a small family owned company, and the owners provide support. They are extremely knowledgeable about their products and responded very quickly to my request for help, walking me through diagnostic steps to identify the problem and offering quick solutions. I can't recall ever getting better support for a product, and bear in mind, I was installing the unit about a year after I originally received it. They had no issue with when it was purchased, warranty, etc. They just helped and made it right.

(2) Locating the module and reinstalling the A/C-Radio assembly. Regarding location of the module, it's best to put it into a place where you can get to it without having to pull the A/C-Radio assembly out of the dash. The space behind that assembly is very tight, and the first time that I reassembled everything, a wire pulled out of the module even though I had been careful to tie all of the cords with a bit of slack. Getting the assembly back in is also somewhat challenging with the new wires having been added, and it's important to get the A/C-Radio assembly fully in before screwing it to make sure that there's no stress on the plastic screw mounts. I found a great solution to improve getting the radio back in. On the driver side, remove the plastic trim attachment holding the top of the carpet next to the A/C-Radio location. Then, pull the carpet back, and you can reach behind the A/C-Radio unit to manipulate cables and the radio into position. That also provided the solution of where to mount the BT module. I ended up sticking it with double-face automobile adhesive to the inside of the metal plate next to the radio, which gave me access to all of the BT module wiring after the A/C-Radio assembly was in. That made life much easier. Another thing that made things go more easily was reversing the installation of the AC controller. It normally requires removal of the entire assembly, then you unscrew it from the back side. There is no apparent reason for this, and it also complicates the replacement of bulbs in the controller display. Given the age of the plastic, my desire to not have to remove the entire assembly in the future to avoid damage, and the benefit of having access into the cavity after the radio and frame are reinstalled, I reversed the screws to go in from the front. Just filled the screw holes in the frame with epoxy, drilled the controller holes out a bit, and used new screws to put them in from the front. Much better this way.

(3) Console re-installation. Console re-installation was advertised as just a reverse of removal, BUT be careful with the carpeting. There are 4 plastic "U" shaped pieces on the inside edges of the console (2 on each side) that the carpet has to be manipulated into to keep the carpet flush with the console after re-installation. If you don't get the carpet into these sockets, there will be a good size gap under the console to the carpet. Look for these on the console before you put it back in so that you know where they are and have some trim tools handy to get the carpet into them. You'll need to reach inside of the shifter hole as the console goes back into position to get the carpet into the slots, and you'll probably end up with some cut fingers before you're done unless you wear some thin fabric gloves.

(4) Remote mic location. I read some other posts expressing concern about the mic location, so I played around with this a bit. I preferred installing it in the blank circle of the overhead console vs. having it clipped to the visor or hanging down from the roof. Before installation, I made a few test calls from the highway with the top down and moved the mic to several locations, including the circle in the console. Bottom line is that there was no significant difference noted by the people who listened to the calls regardless of where the mic was located. At 50+ with the top down, there's enough road noise that the call quality isn't going to be great in any location, but I was told that I was clearly heard and understandable in all of the mic locations that I tried. In the end, I drilled out the circle and press-fit the mic into it with the windscreen foam. I had read about some concerns that this spot was reserved for an occupant sensor for airbags or some other purpose, but in the 1997 model year, it's just a blank space with a semi-circular clip behind it that holds the mic nicely with a bit of double-stick adhesive.

Here are some photos of the installation. The bass boost control and a USB charging port (provided as a feature of the Bluetooth module) were mounted in the blank slots in the center portion of the A/C-Radio assembly that were used in later model years for seat heater control switches.

If you have any questions about the project, please feel free to send a PM.


AC-Radio assembly hole




AC control removed from front after reversing mounting screw direction to allow access behind without removal of entire assembly



Bluetooth module connection from behind carpet





Removal of carpet trim attachment to gain access to rear of AC-Radio assembly and mount Bluetooth adapter




Completed AC-Radio assembly with bass control knob and USB mounted in seat heater control blanks




Cracked plastic storage box latch before repair




3M double-sided automotive adhesive



Epoxy repair of AC-Radio assembly frame



Epoxy repair of AC-Radio assembly frame




Mounted Bluetooth module accessible without having to remove AC-Radio module (but would still require removal of console to gain access)




Microphone installed in overhead console circular blank that was drilled out.





Microphone back side

 

OnFire,

Thanks for the update on your ongoing stereo upgrade. I've been thinking about something similar and your chosen Bluetooth unit looks DIY-able.

I'm planning get around to it when I finish my mechanical / bodywork jobs - so that'll be around 2021 then!

 

Well done....