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The the "radio" isn't working from any source. Total silence. It made a very loud pop in all speakers (esp the subwoofer) when I turned on the ignition a few days ago and hasn't worked since.

I checked all the under seat fuses. All good

I assume I've blown up my main amp and a professional installer has told me a) they blow up often, chiefly due to water damage b) Harman Kardon units are NOT repairable.

Prices on eBay are wild... From £50 to £300.

Please tell me what I need to know...

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Chasman wrote:

The the "radio" isn't working from any source. Total silence. It made a very loud pop in all speakers (esp the subwoofer) when I turned on the ignition a few days ago and hasn't worked since.

I checked all the under seat fuses. All good

I assume I've blown up my main amp and a professional installer has told me a) they blow up often, chiefly due to water damage b) Harman Kardon units are NOT repairable.

Prices on eBay are wild... From £50 to £300.

Please tell me what I need to know...

If you have the high end Harman Kardon DSP amp XQK100340 in the rear then they are unobtainable new (although JLR have them listed at £1,165.40 they are out of stock). They cannot be repaired & used go from £200-£430 all with little or no warranty so you could pay £400 & have it crap out in a couple of months time just like your 20+ year old DSP amp did. Even non-working 'for parts only' are on offer for £50. Who on earth is paying £50 for a broken amp that cannot be repaired?

Apparently the Harman Kardon DSP amp XQK100210 from the Disco 2 is plug compatible but only the front speakers & sub woofer will work. These amps are still available new. One listing on eBay is rather optimistically offering a new one at £249 while another seller has them new for £50. Used but working examples are £30 & upwards. I bought a new £50 one as my HK DSP amp failed a few weeks back but I haven't had the chance to fix it in yet & left it in the garage in the UK when I travelled over to Brittany. I will be back in the UK next week so hope to get a chance then.

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Thanks for the quick reply. Why aren't they repairable?

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The problem would appear to be thermal as they will sometimes start to work but then stop again when the temperature changes. Most likely theory is that the processor chip (a surface mount device with tiny pins) is encapsulated in a big blob of resin which has a slightly different coefficient of expansion than the chip itself so they will shear off the PCB. Because of the resin you can't get to the pins to be able to do anything with them. So far, nobody has managed to find a way of getting the resin off without destroying the chip underneath it.

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Makes you wonder what were they thinking, eh? :-)

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I'll buy a £50 parts only one and take a look.

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If you can work out a way of dissolving the resin, there'll be a lot of people that could benefit. People have tried multiple different solvents, freezer spray, heat and nothing seems to work in getting it off without poking or levering at it which destroys the chip.

I've got one that I intend using the connector and casing and putting a pair of Class D amps and 4 crossovers in it to make a plug and play replacement. I've got all the bits, just never got around to putting it together.

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Thinking of using this to dissolve epoxy if necessary:

https://www.mapei.com/it/en/products-and-solutions/products/detail/ultracare-epoxy-off-gel

However, I think it's the power supply. As there are two DSP chips, blowing both seems unlikely, blowing one would only affect one side.

Having this blow after my successful subwoofer rebuild has put me into a bad mood. It's like that fairground game where you hit gophers with a mallet... tempting...

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If I want to bin it, is there a two box solution where I can replace the DSP amplifier and head unit, leaving everything else in-situ? I'd rather not have to remove all 4 door cards.

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Marty supplied the original information, I've refined it a bit and written out the way to do it if you want to go with an aftermarket head unit. No need to take the door cards off as all wiring goes via the DSP amp location so it can all be done from there. See this thread here https://rangerovers.pub/topic/8-info-p38-alpine-dsp-amp-connections-and-wiring?page=1#pid30814

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Rather that open a new topic, since we are into this, I will - kindly - hijack a little this one.

I got the Hi-line system, no DSP but just the amps in the doors and sub in the rear.
Years ago, as the CD changer had developed a lot of 'jumping', I took the headunit out and replaced it with a Pioneer DEH-X3500UI (should have gone for the BT version, but back then I wanted to piggyback an AVIC to the Pioneer, thing I never did afterwards), and using the info from "the other website" I fitted some attenuators.
After years of use, they are starting to crap out and is time for a new solution, or to fix them up, but my friend who did that no longer has the chance to assist in this.

Richard here https://rangerovers.pub/topic/3322-hi-i-m-new?page=1#pid40824 mentions fit crossovers as an option, but not knowing the specs of the original speakers, how to know which frequencies to cut at?
Anyone that has tried this solution and was successful?

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Gilbertd wrote:

Marty supplied the original information...

Cool! Thank you.

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EDIT: DO NOT DO USE THIS UNIT

IT'S A DOUBLE DIN UNIT WITH CD. IT IS TOO BIG AND TOO DEEP FOR THE HOLE WHERE THE SATNAV WOULD GO.

WILL USE THE ONES GILBERT RECOMMENDS IN THE NEXT POST.

Okay peeps. Total change of plan, I want to fit a Kenwood DPX-7300DAB and use Gilbertd's rewiring guide.

https://www.kenwood.eu/car/receivers/dab_cd/DPX-7300DAB/

It has 6 RCA outputs (front, rear and subwoofer) all described as "preouts"... that said, they are 2.5V, so apparently 50W per channel... Not sure where that number comes from.

Q1 Does that mean I need the 4 amplifier kits in the pinned post?

Q2 Does the subwoofer have it's own amplifier?

Q3 Is the second subwoofer RCA for running 2 subwoofers?

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  1. No, that is the same unit my daughter has in her Toyota Celica. It has preouts but it also has speaker level outputs on the DIN connectors so you ignore the front and rear, left and right outputs.

  2. Yes, the existing P38 sub has a built in amp, but you will need to connect the sense wire to the electric aerial output on the head unit to cause it to power up

  3. You could run two subs or some subs want a stereo input (which is a bit pointless).

I'm a big fan of the Kenwood stuff, I've got a KDC-BT73DAB (previous version of the current KDC-BT760DAB except it has a better 3 line display) in mine and I can't fault it.

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Gilbertd wrote:

  1. No, that is the same unit my daughter has in her Toyota Celica. It has preouts but it also has speaker level outputs on the DIN connectors so you ignore the front and rear, left and right outputs.

  2. Yes, the existing P38 sub has a built in amp, but you will need to connect the sense wire to the electric aerial output on the head unit to cause it to power up

  3. You could run two subs or some subs want a stereo input (which is a bit pointless).

I'm a big fan of the Kenwood stuff, I've got a KDC-BT73DAB (previous version of the current KDC-BT760DAB except it has a better 3 line display) in mine and I can't fault it.

Thank goodness I've got a working solution!

I assume the electric aerial pin is hidden in the ISO (DIN?) with the speakers?

EDIT: found it on pin 8!

Thanks Gilbert

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The sense wire to the sub is the Grey/Black so that is the one you need to connect to 12V when the radio is switched on. Electric aerial output is usually Blue/Yellow from a head unit. Although I've got the users manual for your head unit on my laptop, I don't have the installation manual. That is at home and I'm quite a distance away at the moment.

leolito wrote:

fit crossovers as an option, but not knowing the specs of the original speakers, how to know which frequencies to cut at?
Anyone that has tried this solution and was successful?

As it is only a low and high 2 way crossover, it doesn't matter. The bass and mid range speakers are in parallel so get the same wideband input, so it is only the high frequencies for the tweeter that are separated. Tweeters typically work between 2 and 20kHz so you don't need to know the spec of the individual tweeters fitted and can use any cheap 2 way crossover. It is only when you start looking at 3 way crossovers that you need to know the frequency bands you want splitting between speakers.

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Thanks Richard, that clears it up. When I asked my friend that likes to tinker with audio systems, and I mentioned the door had a 3 way speaker system (without knowing the bass and mid in parallel), he went into crazy research mode ... lol

Will try to get some crossovers and be done with the damn thing, again door cards off is becoming a hassle.
Actually I got the passenger window mechanism which starts to groan, so all is a new opporunity!

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I've got everything installed and working except the front right mid/bass which has probably seized. I'll sort that later. However, I have a whining noise coming from the subwoofer. Sounds about 100-150Hz. I have a film clip but as images don't tend to work for me here... The Internet suggested a ground loop as a likely cause so... At the back I've grounded the black cable from the, now redundant, C0491 to the body by the bracket which held the DSP board. Up front I tested the crimp on the black wire into the head unit against a bolt head, and got a tone from the meter. Didn't cure the problem.

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If it's 100-150Hz, then your "whine" is probably hum & caused by using un-balanced line-outs on the head unit to drive amplifiers with a balanced input.

My P38 has a 2-din tough screen in dash, with the actual head unit under the passenger seat. I used 5 x audio balancing transformers on the line-outputs to feed my door amps using the original twisted pair wiring. Result = zero hum, buzz, etc. because anything getting on the wiring is cancelled out by the balancing !!

Info Here

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I don't really understand what balancing means. I known the XLR cables uses in sound systems are balanced. I saw a YouTube of a guy using a cable similar to coaxial, but with two wires in the middle, plus a shield. He wrapped the shield around the wire he was using for ground, linking the shield electrically and physically.

I created an RCA with a short piece of coaxial cable and soldered the core to the orange wire and the shield to the black and orange. It's not the same, but whatever the physics is, I don't see the difference.

I assume the DSP board was either balancing everything or using capacities to kill the hum? Components of it may be much higher than my estimate, it's high enough that my high frequency hearing loss (>15k) is making it seem quieter to me than what my wife is hearing.