Re: Upgrading sound in 4000

[John Greenstreet <jgreenst@motown.ge.com>]

> From quattro-owner@swiss.ans.net Mon Aug 15 10:09:21 1994
> From: Dan Simoes <dans@ans.net>
> 
> If they are the same as in our '88 90 maybe they are shot - the system
> in the 90 is surprisingly good.
> 
> I believe there is a set of Infinitys that drops right in to the
> front of the 90 - the fronts are driven by the head while the
> rears are the `active speaker' design.
> 

Right, that's something to consider if one wants to change the speakers
in a newer model; the amplifier is invariably integrated with the
speaker.

In all the Audis I've owned, the front speakers were fine, it was the
rears that could be improved.  In my 1982 4000S, I removed the 4" round
speakers, enlarged the holes in the rear deck cover as well as the
metal rear deck itself to 6x9, and mounted the speakers on the rear
deck.  I then sealed everything up with Mortite rope caulking and
filled in the gap between the rear deck and the cover with foam.  The
resultant sound was stunning.

What improved the sound so much was not so much due to the speakers as
to the mounting.  Speakers should be mounted on a rigid, non-resonant
surface, as a flexible surface will absorb the air and cone movements
the speaker is trying to produce.

The cardboard rear deck cover is a good example of where not to mount
speakers, unless a physical connection can be made to the metal rear
deck in order to damp out vibrations.

In my 100CS, which has an already-excellent Bose sound system, I
"tightened-up" the bass response by sticking a single sound-dampening
sheet in the center of the rear deck on the trunk side.  Such sheets
are made by Wurth and are available from Griot's Garage.

As for speakers, I prefer those made by Canton and or Boston
Acoustics.  Canton makes speakers especially good for German-car
applications, as does M-B (don't remember what it stands for right
now).

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John Greenstreet, Senior Engineer           (jgreenst@motown.ge.com)
Martin Marietta Government Electronic Systems    Moorestown NJ 08057
WPI Class of '75, Temple Class of '94

My new car history:
1972     1975       1978      1982       1986        1989      1992
 VW  ->   VW    ->  Audi  ->  Audi  -> Mercedes -> Mercedes -> Audi
SBug   Scirocco   Fox GTI     4000S    190E 2.3    190E 2.6    100CS

POSSLQ's* new car history:
         1978       1981       1985      1988        1990      1993
       Triumph ->  Toyota ->  Toyota  ->  VW    ->   Audi   -> Audi
       Spitfire    Tercel     Corolla   Jetta GL      80       90S

*POSSLQ = Person of Opposite Sex Sharing Living Quarters
Note: All Audis and Mercedes above were sold to friends or family.
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