Rear Parcel Shelf speakers not working (non-Bose)

[HPsauce]

I think the title says it all really.
This is a spin-off from another thread to keep topics clean.

Trying to resolve problems with my RNS-D in a facelift D2 S8 I realised that there was no sound from the shelf speakers and that the rear doors aren't exactly "sparkling" either, though they do work. Better with the Fader seriously biased to the rear though.

A comment by Notorious suggested that they never work.
Is this really true, there's an awful lot of "stuff" under the shelf in the boot.

[briang9]

mine do work HP (also non Bose) but think they only deliver bass, certainly with the fader biased towards the back they do produce a fair amount of thump which can be clearly heard when you open the boot lid

[HPsauce]

Originally Posted by briang9

mine do work HP (also non Bose) but think they only deliver bass

Thanks, what head unit do you have and do you know how it's coded?

[briang9]

Originally Posted by HPsauce

Thanks, what head unit do you have and do you know how it's coded?

mine is an RNS-D, not sure about the coding but I did change the NAV part of the unit for one that came from a BOSE car and had to have it recoded to get front speakers to work, no idea what codes are/were though, Richard (Psyche) did it for me at the time

[HPsauce]

OK, that's very similar to my current setup.
I've had the covers off inside the boot and there are 2 speakers there, with multiple wires as you'd expect. But very little sound noticeable in the boot.

If I put the RNS in max Bass, min Treble, fully faded to rear and then stick my head over the rear seat above the parcel shelf I CAN hear some bass sound, but it's really quite faint.

Picture of one of the speakers attached, looks like 4DO 035 401 3QG.

Anyone know how you get them out so I can test voltages?
Edit: You undo 2 rather obvious Phillips screws inside the boot and they just lift up inside the cabin. Though it looks like they've been out before from markings on the paint.
Will investigate later, but on really high volumes you CAN hear the bass, so I'm thinking it's more an RNS-d issue.

[PsYcHe]

Can't remember what the coding was, but I think I had to code it to an A6 setting.. Though VCDS had the options listed.

If you're getting some sound out the rear speakers then I'd assume that the coding is correct.. If you drop the old stereo in, does it work?

[HPsauce]

Originally Posted by briang9

they do produce a fair amount of thump which can be clearly heard when you open the boot lid

OK, I put my fader right to the back (well 2 clicks short) and cranked up the volume and there is a vague rumbling in the boot. And I can feel vibration if I put my hand on the speaker units in the boot or the covers inside on the shelf. Not a "thump" in any sense.

[PsYcHe]

Pretty sure the two boot speakers have their own amplifiers.. check for voltage at the pins and see if they've maybe just both failed

[HPsauce]

I'm also quite certain of that, and IIRC they then feed the rear door speakers so there will be a filter mechanism in there as well, so multiple wires rather than just 2.
Not sure what voltages to expect and the audio signals will presumably be AC.

It "sort of" works but is extremely faint.

When the rain stops I'll try to find time to get my multimeter (and screwdriver and torch) out. I just love lying on my back in the boot.