91 90q20v audio install (long)

["Mark L. Chang" <mchang@ece.nwu.edu>]

-Just thought I'd post my experiences regarding installing audio stuff
in my (new to me) 90q20v.  If you don't care, hit "D"elete now :).

Motivation:
PO put in an Alpine head unit, which was all good.  Then, someone decided
that they wanted it, broke a window, and took it.  Ah, what better reason
to upgrade (cough, cough)! 

(As a side note, please to not take your cars to Autosonics in the North
Suburbs of Chicagoland USA.  Looking at the wiring job they did for the
PO, it was sh*t.  Alternator whine everywhere and bad psuedo-splice with
wire nuts, electrical tape and everything else terrible you could
imagine.)

Parts (FYI):
(1) Rockford Fosgate RFX-8130 CD head unit -- matches 90q20v interior
orange/red illumination perfectly.  Decent head unit, and much much
cheaper than their flagship (at the time) 8140.  5-channel preouts so you
have fine control over subwoofer levels.
(2) Zapco AG360 amplifiers.  50wx4, and bridgeable.  Beautiful amplifiers.
If you have the means, I highly recommend them :).
(1) JL Audio 10W6
(2) Audax HT100K0 -- 4" carbon kevlar cone mid/bass.  Decently flat
response that goes low as can be expected for a 4", and reasonbly high as
well.  Cheap, too.
(2) LPG 26NA 1" tweeters.  Neodynimum magnet, aluminum dome.  Efficient,
and they go -low- for tweeters.  Decent pairing (IMHO) with the Audax.
(2) 12dB crossovers from Madisound.  I just let 'em make them from a Leap
design.
(2) Madisound Sledgehammer 5.25" coaxials for the rear deck.  Madisound
woofer/mid with an Audax (DW50M?) tweeter mounted on a vented pole piece.
(?) Miscellaneous wiring, including:
-   100ft of speaker wire (you will need TONS of it if you plan on
    biwiring the front stage like I did.  do _not_ underestimate the need
    for speaker wire!)
-   5m of RCAs (just long enough) (I used Phoenix Gold ZeroPoint-no noise)
-   20ft of 4ga power
-   4ft of 4ga ground
-   8ft of 8ga power
-   8ft of 8ga ground
(?) Distribution blocks, fuse blocks, fuse, etc. etc...

Construction:
Subwoofer enclosure.  The 10w6 requires just about .5 cu.ft. of airspace
in a sealed enclosure, whichis good, since the 90q20v doesn't have much
trunk space to begin with.  I made a wedged-shaped enclosure for the
passenger-side trunk well.  This gives me a little more volume than a
straight-up box, plus allows me to use a 10" sub instead of an 8".  The
box for an 8" with about .25-.4 ft^3 would be easier to make.  The wedge I
made is such that it kind of matches the contour going toward the front of
the car.  I finished it in black felt to match the trunk lining.

Amplifier rack.  The Zapco amplifiers are huge, plus I have two of them.
A 20v lister recommended the space behind the spare tire well on the
driver's side.  There is a lot of room there, but not enough for my
application.  I cut some 1/4" plywood to fit the trunk floor space between
the bumper rails.  I cut it exact to make it a tight pressure-fit.  It
stays jammed in there nicely without using screws.  I'm keeping an eye on
movement over bumpy roads, though, and may screw it down with brackets to
the bumper rails if necessary.  Finished it in the same black felt and it
matches well.  Mounted the two amps, two crossovers, and power/ground
distribution blocks to it with screws and tie wraps and wire guides to
make it look kinda pretty.  It ended up pretty packed in there.

Amplifier rack cover.  I fashioned a cover out of .5" plywood and finished
it in black felt.  This cover fits on top of the bumper rails and just
clears the amplifiers in the well rack.  It is also cut for a "shove-in"
fit.  One edge pressed up against the spare, the other pressed against the
sub woofer box.  With it in place, you cannot see any wiring or
amplifiers.  Very stealth.

Installation:
Overall, this install was easier than my 4kq, mostly because no door
panels had to come off.  I'll describe it in the order I performed the
install.  Best grab a Bentley for the wiring of the head unit.

Disassembly:
-Remove rear seat bench.  Two screws and lift and pull.
-Remove rear seat back.  Bend tabs at bottom to free the hooks, lift and
pull out.  10x easier than on the 4kq which requires two people to do
right.
-Remove door sill covers.  One plastic cover rearwards from the base of
the seatbelt gets unscrewed, and one screw under where the rear seat bench
used to be.  Three or four retaining clips hold in the rest of the sill,
so you just pull gently and it pops out.
-Remove lower dash covers on driver's and passenger side.  Six hex-head
bolts in total.  You can leave the glovebox installed.
-Remove speaker grilles by prying gently.  Remove speakers.
-Remove dash vent grilles on either corner of the dashboard.  This is
where you will mount the tweeters.  (More on this later.)
-Remove radio.  Let thieves do this for even quicker de-installation!
-Remove spare tire.
-Pull back trunk carpet that lines the sides and covers the gas tank.
Might just consider removing it entirely for now.
-Remove screws from kickpanels.  Driver's side means the screws
holding the hood release lever (2) of them.  Pull back door
weatherstripping and you can pull these guys out.

Wiring:
-To run the 4ga power wire from the battery to the trunk, I found an
unused rubber hole plug just above where the accelerator cable comes
through the firewall.  Pop it out, and voila... a hole!  I actually
drilled out the center of this little rubber piece and fed the wire in
through there to make it a "grommet".  Feed some down into the
driver's side footwell and pull it through.  Watch where you route the
cable to avoid pedals and other moving mechanisms.  Use cable ties
here to keep it in place.  Run the wire over to where the kickpanel
used to be and run it under the carpet, down the door sill, and into
the trunk over the rear wheel well.  Make sure to run it on the
correct side of the seatbelt!  In the trunk, you can feed it under the
trunk lining on the driver's side and pop it into the trunk floor
"well".  Under the hood, as close as possible to the battery, put some
sort of fuse block to protect your system.  I ran the 4ga from the hole,
into the windage tray through one of a series of holes above the battery.
Under the weather cover in the windage tray I put a fuse block and fuse.
Put on a ring terminal and ran the remaining wire through another hole on
the (+) terminal side of the windage tray and hooked it up to the battery.
NOTE: do not actually install the fuse until you are ready to play.  I
used split loom tubing to cover the exposed wiring in the engine bay and
over through all the holes in the windage tray.  Don't want anything to
wear through the insulation jacket!
-Run your ground wire to the factory ground point on the rear
driver's side tail-light cluster.  There is a bolt and a bunch of wires
already grounded there.  Add your ring-terminal'ed 4ga ground wire there
and run it into the trunk "well".
-Run the RCA cables down the opposite side of the car as the power.
Feed it through the opening in the dash, under the glove box, and
under the carpet by the kick panel and into the trunk.  Slide it under
the filler neck for the gas tank and behind the carpet and into the
"well".  If you're lucky, your RCAs will have an integrated "turn on"
lead built in so you don't have to run a separate wire.
-Speaker wire needs to run up to the front as well, and to the rear
deck.  Easy.  The only tricky part is to get speaker wire up to the
tweeter position in the dash vents (more later).  The only thing
separting the holes it a little foamy stuff.  Just poke a screwdriver
through from the vent to the speaker opening to break up the foam
backing of the dash, then you can feed in speaker wire.

Head unit:
You really only need a few wires from the original harness.  I chopped my
harnesses off since I do not have access to the original head unit and
will never ever use it again.  Plus, the original harness was mangled once
by the installers for the PO, and again by the thieves -- there was very
little left of the original harness that wasn't shredded.

You will probably want to use the rear antenna, as it is dual-band (AM and
FM).  You will probably need to get an adapter for the rear antenna lead.
It is non-standard.

Wires you probably need:
Power
Ground
Illumination
Antenna power
Ignition switch -- most of our generation Audi's do not have a switched
                   ignition lead.  I was going to use the "key inserted"
                   lead off of the ignition switch, but forgot completely.

Speakers:
I mounted the HT100K0 in the original opening.  They are too large to fit
down all the way into the original opening, so I just left them sitting on
that "lip".  I may file the lip down later if I think it's worth the effort.
For now, they fit just fine and don't move around at all.  We'll see.

I put the tweeters into the dash vents.  I won't get good side window
defrosting with these in place, I know.  To be honest, I was prying off
one of the dash vent "louvres" to see the hole in there when I busted a
couple louvers off (don't work on your car in the cold morning... grrrr..
plastic is brittle when cold).  Since now it was damaged, I thought, hell,
I'll mount them here to start with!  I had to file down some of the "lip"
that surrounds the cutout, but not much, to fit in that LPG tweeter.  It
pops in there snugly and looks neat.  We'll see how the winter treats me
without side vents.  I've never had a car with them before, so maybe I'll
be okay :).

Installation is reverse of removal!

If anyone wants pictures, I can develop a few that I took of the install.
No "in-situ" pictures cause I was dirty and didn't remember, but finished
photos galore :).

Mark


                               A file that big?
                               It might be very useful.
                               But now it is gone.
                               -- David J. Liszewski