update on alternator noise over speakers

[Ti Kan]

=?iso-8859-1?q?mike?= writes:
> >you also gain the benefit of one really large
> > capacitor in
> > parallel to the head and amps. 
>
>  don't understand this...care to explain?

The battery acts as a very large capacitor, with very low internal
impedance, supplying lots of current when needed.

The moral of the story is that for aftermarket stereo installations,
it is a good idea to wire the power and ground of all audio components
(head unit, amplifiers, electronic crossovers, equalizers, etc.) directly
to the battery.  Use heavy gauge wiring on both the power and the ground
lines, and an appropriately sized fuse on the power wire right at the
battery.

For high-current components such as the power amplifiers, they should
have their own power and ground wires to the battery (especially if the
wire run is long, like from the trunk).  Low-current components (electronic
crossovers, equalizers, or head units if its internal power amplifier is
not being used) can "share" the run (i.e., power and ground wires each
collected to a respective a single point, the run to the battery with a
nice heavy wire).  This reduces the number of wires that have to pass through
the firewall and makes it easier to install, while providing the benefit
of the aforementioned "star" configuration of power and ground.

The merit of this arrangement is that other electrical devices in the
car which causes noise/spikes on the car's electrical system (ignition
system, lighting, ECUs, etc.) has minimal chance of interfering with the
audio system's power and ground lines, and reduce the likelihood of
ground loops.

-Ti
01 S4 2.7 biturbo quattro
84 5000S 2.1 turbo
80 4000 2.0
96 A4 2.8 quattro (sold but not forgotten)
-- 
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Research Laboratories, Sunnyvale, CA. USA
  ///    ti at amb.org
 //////  http://www.ibiblio.org/tkan/
///