Help with A4 back speakers

[Sat]

I am having a problem with the rear speakers in my 2001 audi a4, the
front speakers seem to be fine but the rear speakers seem to play at a
very low volume also I do not think the rear sub woofer is working.

I have been told they work on a seperate amplifier but I am unable to
locate it.

Does anyone know where I can find a detailed wiring map of the standard
audio, or has anyone heard of this problem before?

thanks for your help..

[In-Car Express]

Post by Sat
I am having a problem with the rear speakers in my 2001 audi a4, the
front speakers seem to be fine but the rear speakers seem to play at a
very low volume also I do not think the rear sub woofer is working.

If you've got an aftermarket head unit fitted, this is probably
because of the interface. The Autoleads interfaces in particular have
a low sensitivity input, so unless the head unit has high voltage
preouts, the rears tend to sound fairly quiet. To overcome the
problem, you can bypass the amps, or fit a line-driver between the
head unit and interface.

Jon

[Glenn Richards]

Post by Sat
I am having a problem with the rear speakers in my 2001 audi a4, the
front speakers seem to be fine but the rear speakers seem to play at
a very low volume also I do not think the rear sub woofer is working.

You'll need to fit a line driver between the head unit and the Autoleads
adaptor, something like the Vibe DeltaBox.

Post by Sat
I have been told they work on a seperate amplifier but I am unable
to locate it.

It's mounted on top of the rear offside wheel arch (on RHD models).
You'll need to remove the right hand trim panel in the boot. To do this,
take out the spare wheel and remove the two nuts holding the plastic
trim at the bottom of the boot lip in place. Remove the trim by pulling
sharply upwards, but be careful not to break the cable attaching the low
level interior light to the wiring loom! This will detach simply by
squeezing the sides of the plug.

To remove the trim panel, firstly remove the split fastener located
about 2 inches from the end of the panel nearest the rear of the car on
the floor of the boot. You'll then need to release two fasteners
attaching the trim to the car chassis - be careful not to wrench the
plastic mountings off the back of the trim panel when doing this.
Finally unhook the trim from the metal lug at the top of the trim panel.

You should now have enough access to pull the panel forward and be able
to see the amplifier, it's a silver aluminium extruded box bolted to a
bracket on top of the wheel arch. To get any further you'll need to
remove the panel completely. Undo the three fasteners holding the carpet
trim in place on the back of the rear seats and pull the carpet forward.
You should now be able to unhook the trim panel and remove it.

However, if you're not planning to add additional amplification, I would
suggest simply installing a DeltaBox line driver between the head unit
and harness. There's plenty of space behind the air-con control panel to
install this device (in fact there's masses of space behind there for
all sorts).

In case you haven't guessed from the above, I have an A4 (2003 model,
before that a 2001 model). Comments regarding removal of trim apply to
saloon model, if you have the Avant (estate version) then the procedure
is probably somewhat different. I haven't stripped an Avant, so I can't
offer any advice on that.

Hope that's of some use anyway.