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Hello I have a 2001 p38 an the radio comes on but no sound... I hear a clicking sound coming from the sub area ...can anyone help me figure out what happen an how to fix it plz 馃檹馃徎
 

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Your DSP amp in probably dead. It's located behind the sub inside the boot area.

These are not repairable so you either have to source a good used one, or replace the head unit with a new one.
 

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Thank you .!! So when you say head unit you mean the amp? I was thinking just getting new amp an new sub
 

LEGACY VENDOR
1995-2002 Range Rover P38A
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Look up under my username, as I've done a LOT with the audio system on the DSP version of the P38 - mostly stemming from when I bought the RR having no audio either. I found my DSP amp was totally missing, so started from scratch with fitting a new head unit/crossovers, and even went as far as making a fairly comprehensive spreadsheet (available in PDF) of all the wiring colours/functions/connectors etc in the DSP system to help others who wanted to try and modify the system.

The DSP amp controls everything in the later models - whilst the subwoofer has it's own amp, the actual feed to it comes from the head unit, and then into the DSP amp - where it's processed (the level is boosted/attenuated as required) before then being fed into the subwoofer amp.

Unfortunately it's not just as simple as replace the head unit if the amp is dead - there is re-wiring to be done if you want it all working properly. The DSP system only uses a left/right feed from the head unit, and then all of the audio manipulation for the 4 doors, bass, treble, fade, balance, subwoofer, and DSP settings are all handled in the DSP amp itself.

So as a minimum to get sound from all 4 doors with an aftermarket head unit, you need to run 4 more wires for the rear left/right +ve/-ve input feeds from the head unit to the loadspace to be connected to either a standard amp, or the speakers directly depending on how you drive it.

I now do a DSP replacement amp board which utilises 4 of the more common P38 door amps on a piece of alloy sheet, which then bolts into the location of the DSP amp, and then has a custom wiring loom to wire into the vehicle wiring. It also includes the additional wiring for the rear door inputs. This then allows you to either use the factory head unit (it will drive all 4 door amps from it, if it doesn't detect a DSP amp on power up - the head unit part number was the same for both DSP and non DSP versions), or you can fit an aftermarket head unit with either attenuator circuits to drop the amplified output levels from a normal head unit to the low-level input expected by the door amps, or you can use line isolating transformers and RCA pre-outs to drive them.

I hope this gives a bit more info on the system - as I mentioned - look under my username, there are a least a few threads on this DSP system from when I went through it all about 8 years ago.

Marty
 

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The DSP amp controls everything in the later models - whilst the subwoofer has it's own amp, the actual feed to it comes from the head unit, and then into the DSP amp - where it's processed (the level is boosted/attenuated as required) before then being fed into the subwoofer amp.
Hi Marty,
I've just spent a few hours reading all your posts and they're great. Just one question - how do you know if you have a DSP amp model vehicle or if the amps are in the doors...you mention later models? (Its pouring here in Aus so I can't pull of doors trims just yet to see if there are amps there). My P38 is 11/2000 and my goal is to just replace the Alpine head unit with something newer with bluetooth/usb support.
Thanks,
Vlad
 

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On the Tone or Sound button (can't remember what it's marked as on an Alpine) do you have a DSP option or just the standard Bass, Treble, Balance and Fade? If no DSP option, you don't have it.
 

LEGACY VENDOR
1995-2002 Range Rover P38A
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Hi Marty,
I've just spent a few hours reading all your posts and they're great. Just one question - how do you know if you have a DSP amp model vehicle or if the amps are in the doors...you mention later models? (Its pouring here in Aus so I can't pull of doors trims just yet to see if there are amps there). My P38 is 11/2000 and my goal is to just replace the Alpine head unit with something newer with bluetooth/usb support.
Thanks,
Vlad
As Richard says - pressing the music note button will scroll through the head unit options and there should be a DSP one there - with the options being "OFF, Spatial, Driver".

Another way to tell is to release the head unit and pull it out. On DSP versions the audio output ISO block will only have 4 wires in it instead of 8 (as the DSP unit only takes a left/right feed and then mixes it for each door, models with amps in the doors have 8 wires for 4 outputs - one to each door, and the head unit does the mixing internally). Also on DSP versions, then mini ISO connectors at the top of the head unit will have a pink/black wire coming out of the green on - which is the communication line to the DSP amp. If there isn't a pink/black wire and 8 wires in the audio ISO, then you'll have door amps. Pink/black wire, and 4 wires in the audio ISO and it's a DSP version.

Oh, also, most DSP vehicles had factory nav fitted - so if you don't have that, then I would have a hunch that you'll have door amps.
 

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Oh, also, most DSP vehicles had factory nav fitted - so if you don't have that, then I would have a hunch that you'll have door amps.
That is true for the UK and US market I suppose but it does not apply eveywhere.
All Greek market cars for example had the DSP amp but no nav, as the mapping was not yet available at the time.
 

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As Richard says - pressing the music note button will scroll through the head unit options and there should be a DSP one there - with the options being "OFF, Spatial, Driver".

Another way to tell is to release the head unit and pull it out. On DSP versions the audio output ISO block will only have 4 wires in it instead of 8 (as the DSP unit only takes a left/right feed and then mixes it for each door, models with amps in the doors have 8 wires for 4 outputs - one to each door, and the head unit does the mixing internally). Also on DSP versions, then mini ISO connectors at the top of the head unit will have a pink/black wire coming out of the green on - which is the communication line to the DSP amp. If there isn't a pink/black wire and 8 wires in the audio ISO, then you'll have door amps. Pink/black wire, and 4 wires in the audio ISO and it's a DSP version.

Oh, also, most DSP vehicles had factory nav fitted - so if you don't have that, then I would have a hunch that you'll have door amps.
Ok great, I'll be removing it this weekend and I'll check it out. I can't scroll through the options because its a dead unit atm. But I don't have sat nav either so my money's on my P38 having door amps.
Cheers Marty.
 
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