2012 D4 TDV6 Harmon Kardon sound issues

[Fozzie]

Hi all
This one is doing my head in

2012 D4 TDV6
Harmon Kardon (not logic 7)
With the large screen

Everything was working fine and then one day - no bass or lower mid range sound

The Subwoofer still works but everything else sounds tinny

Action so far
Via wreckers
Have replaced
- the Head unit
-And AMP(in the rear of car)
-the MOST channel looks to be working
-It doesn’t matter where I put the fade/balance same ****ty sound regardless of speaker

The questions on my mind are
1. Is there some other device the processes the audio between the AMP and Speakers
2. are the speakers to blame (if so how to 4 or so speakers all go at once?)
3. I haven’t replaced the screen unit - but surely that doesn’t process the sound?

What am I missing
Need my tunes

Help??!
Ps anyone want to buy a spare head unit or amp[emoji35]

Thanks
Foz

[DiscoJeffster]

@cambo will hopefully be along to advise.

[Fozzie]

Actually bit of an update
In terms of sound it’s sort of sounds like poor Mono

I dunno grrrr

[Fozzie]

Help anyone ??

[Tombie]

Patience... You could message "Old Jaguar" on FB or Cambo on here.

Not everyone reads everything daily or hourly!

[Eric SDV6SE]

Actually bit of an update
In terms of sound it’s sort of sounds like poor Mono

I dunno grrrr

Sounds to me you've had Donna Summer up too loud and burst a speaker cone.....

[veebs]

What input are you using? Same problem on all sources?

I've had ****ty sound in the past myself - turned out to be a loose headphone jack on the Aux input...

[Fozzie]

Hi Veebs

All sources
CD
BLUETOOTH
RADIO

very frustrating

[Fozzie]

Sounds to me you've had Donna Summer up too loud and burst a speaker cone.....

Maybe John Denver [emoji23]

But it’s on all speakers
Unless the lower to mid range is only delivered by the front

Even then… to blow 2 speakers at exactly the same time ?

There must be something central I have missed???

[veebs]

Have you checked the fuses in the car?

I don't have a 2012, or even my own D4 to check, but I would start with:

Fuse 2 in the upper compartment (behind the glovebox) - should be a 10A
and Fuses 41, 64, 67 and 68 in the lower compartment

Fuse Box Diagram Land Rover Discovery 4 / LR4 (2009-2016) (https://fuse-box.info/land-rover/land-rover-discovery-4-lr4-2016-fuses)

[Fozzie]

Thanks Veebs will do

[veebs]

Let us know if it worked, I like these puzzles :-)

[Fozzie]

Update

I have checked all fuses

It must be the speakers - right ??

Can you blow multiple speakers at the same time ?
High range and subwoofer still work

Help and stereo peeps out there ??!

Help
Foz

[BradC]

If it were me, I'd pull the amp out and test each speaker one by one from the connector at the amp.

I'd do that by finding a signal source. Anything designed to drive a speaker would do (a tranny with the speaker pulled out, small hifi amp, anything with an external speaker output). I'd grab a pair of wires and shove them in the appropriate socket pins a pair at a time and see what it sounds like.

Looking at the wiring diagram, the tweeters and midrange are paired and probably use a passive crossover with a series capacitor to the tweeter.

If I were taking a WAG (which I am) at the least likely thing I could contemplate that would be an amp fault that happened to send DC to the output would then cook the midrange and leave the tweeter unscathed.

Could be anything, but testing it is not difficult once you've found a signal source. My multimeter has a sig-gen built in, and my ESR meter puts out a nice ~500hz buzz. I've used both to find faulty speaker wiring before, but its not critical and you can get creative.

[Fozzie]

Wow BradC I only understood 50% of what you said

Basically - are you saying the Amp could be the issue?

Or are you saying something has cooked my bass/mid range speakers

But by going through each speaker on the amp you will find out

So - I don’t know what rich plug on the Amp drives what

Do you have a diagram

Many thanks
Foz

[NavyDiver]

Hi Veebs

All sources
CD
BLUETOOTH
RADIO

very frustrating


Edit- listen to Brad

############################# deleted [thumbsupbig]

[BradC]

Wow BradC I only understood 50% of what you said

Basically - are you saying the Amp could be the issue?

Or are you saying something has cooked my bass/mid range speakers

But by going through each speaker on the amp you will find out

So - I don’t know what rich plug on the Amp drives what

Do you have a diagram

You said you replaced the amp, so I'm Ass-u-me(ing) it's not that and the speakers are toast, and yes to the rest.

Page 94 (p107 of the PDF) is what I figure you have. If it's not that one then it's a few pages down. The connectors all ave pin numbers so by poking around you should be able to make each speaker squawk if it hasn't been cooked.

https://www.aulro.com/afvb/l319-discovery-3-and-4-a/285102-later-d3-wiring-diagrams.html#post3122040

[Fozzie]

Thanks heaps Brad
Will dive into this

[Fozzie]

Hi all

While I prepare to do what Brad advised

I went hunting for replacement low/mid range speaker set that will fit

It “seems” that to make it all fit properly you need to
1. Replace with OEM (Meridian-2012) speakers or
1a. Upgraded Meridian speakers???
2. Replace all 4 - front and rear left/right

Does anyone know where to get these ?
I searched on eBay / web with not a lot of luck

Does anyone have the part numbers for the
1. Mid range Meridian speakers
2. Premium Meridian speakers

3. Also do the equivalent RangeRover speakers fit?

4. And finally- on the flip side has anyone replaced these Meridian speakers with aftermarket - Eg. Alpine Bose etc etc?

Help and advice welcomed
Thanks heaps
Fox

[DiscoJeffster]

I cannot believe you’ve killed all the speakers. It’s just unheard of. You said you replaced the amplifier- but you said in the rear. My understanding was the amplifier for the speakers is under the drivers seat. That’s where mine is but I’m Harmon Kardon.

Pull off a door card and flick a 9v across the speakers briefly and listen for a scratchy sound which will confirm they’re working.

[Fozzie]

Thanks Jeff

I am Meridian- so the Amp is in the back

I am in the same mind that it may not be the speakers

But I have already replaced both head unit and Amp
With no change

So unless there is something else in between AMP and speakers it can only be the wire or the speakers- right ??

[veebs]

oooh - fancy, Meridian :)

I still thought there was an amp under drivers seat though? There certainly is in the earlier models...

Looking at the wiring diagram, the amp cable connector for all the high range speakers is separate from the sub and low range - C0491 for bass, C0492 for the high/mids. High and mid speakers run off the same cable from the amp, and split at the speaker using the crossover mentioned earlier. Is it possible there is corrosion in the amp plug?

I'm not full bottle on the setup you have - are there also headphone jacks in the doors? Could one of these have gotten wet or something else in it, and shorted out, to send the car into a state where it thinks it needs to cut speaker sound in favour of headphones? Maybe plug a headphone into each port if they exist, and free them up?

You don't have an IID tool or similar do you, that could read fault codes from the car?

[Fozzie]

Thanks Veeb
I don’t think there is “another” amp under the drivers seat but will check

This is driving me mad!!

[Fozzie]

Update

Pulled the panels off the doors
No surprise all speakers working

Just NO BASS or Mid tones

Circling back to the AMP or head unit
Sigh

This is doing my head in

As I understand it

1. Head unit processes the audio
2. Sends audio digitally via fibre optic to the AMP
3. AMP then de-encodes the data - splits it per channel and pumps it out

So either the AMP is busted or the head unit - BUT as I have replaced both (albeit with 2nd hand gear)

WTF!!! What else could it be?

[BradC]

Have you got the RSE and DVD player? Only ask because that supplies audio to the AMP using SPDIF and not the MOST loop so it'd be a separate source to test with.

I guess the next question is do you have sound coming from each individual speaker? You can use a bit of hose as a stethoscope to listen to each one as you move around the car.

Wish you were in Perth, this would be a fun diagnostic.

[Fozzie]

Thanks BradC
So do I

No only the head unit
And I put my ear to every speaker- all working
(But no bass or mid tones coming from the big speakers)

Question - I did notice that the MOST (Fibre) is a daisy chain - but I did notice yesterday that …. When I unplugged the MOST connector from the AMP only ONE of the lines was lit

I also remember that when I was replacing the head unit - there was only one lit there as well??

Could the cable be stuffed and that’s why this is all happening ?

Cheers
Foz

[Fozzie]

Strike that

It’s a loop - and have checked by shining lights down cable

Argh!

[DiscoJeffster]

Thanks BradC
So do I

No only the head unit
And I put my ear to every speaker- all working
(But no bass or mid tones coming from the big speakers)

Question - I did notice that the MOS (Fibre) is a daisy chain - but I did notice yesterday that …. When I unplugged the MOS connector from the AMP only ONE of the lines was lit

I also remember that when I was replacing the head unit - there was only one lit there as well??

Could the cable be stuffed and that’s why this is all happening ?

Cheers
Foz

One line is in aka receive and one line is out aka transmit. The device it’s connecting to will retransmit on the unlit line.

[Tombie]

Continuity of speaker outputs?

[Fozzie]

Continuity of speaker outputs?

Hi Tombie

Could do with your help - thanks

I have tried to test them but tricky with the plug

I have “listened” to each speaker and each is putting out sound
- but -
the low frequency speakers in each door SEEM to not receiving or putting out the low frequency sound(only the higher frequencies)

I am starting to think that there is a gain issue in the Amp?

And As I have replaced the amp with a wrecker one - it is I suppose possible that the same had happened to THAT amp

Argh this is a pain

[BradC]

I spent an hour last night interrogating Google about this fault (it didn't appreciate the desk lamp in the face with the "ve haf veys oph making you tak") and found several complaints similar with Meridian in the Disco and "Disco light", but no resolution other than "dealer replaced the amp", so given you've given me "affirmative" answers to each question and I have zero familiarity with the funky newer systems, I'm afraid "I'm out".

I suppose I can throw out one last question and ask "have you ****ed around with all the tone controls to make sure it's not something really obvious?".

[Fozzie]

Hi BradC

Thanks man
Yep I have screwed around with the tome yada yada

After more research I keep coming back to the AMP
But having replaced that once (but IT WAS also a 2012 unit - so it also may have been f@@ked ?

Wondering if I can put a 2016 plus Amp in ? To reduce the chance of an older 2nd hand AMP with issues

Failing that - might have get a real audio person to replace everything with a more mainstream setup

Sigh

[veebs]

I dare say a run to Cam at old jaguar in Sydney would sort your problems out, or at the very least, diagnose the issue.

Going for a long shot - have you tried resetting the car, by removing both battery cables and touching them together? I haven no idea what audio settings are stored in permanent vs volatile memory in the car, but if there is some corruption in a setting somewhere (like, the tone being ****ed up, even though you are setting it correctly in the head unit) that might bring it back in line?

[Oliharan92]

Hi I have the exact same issue with my 2012 lr4. Did you manage to find a solution to this?

[Wholistic]

I have the same issue with partially working in a 2010 L322.

I am working to track down a second hand part.