Re: Car audio question...

[Jan van de Wouw <jvdwouw@xxxx>]

On 20-09-2002 12:11, "Hank Eskin" <henry@xxxx> wrote:

> Today I installed my new Alpine radio.
[snip]
> But I have a problem.
[snip]
> Here's the problem: The sound is good upto volume level 14 or 15
> (I know the numbers are meaningless, but it's just a point of reference).

This is only a good point of reference if you let us know what the max
number is... My Kenwood goes upto 35. But my ears hurt over 30...

[snip]
> also pretty sure it the amount of static is proportional to the amount
> of bass in the music and/or the bass setting on the radio.
[snip]
> I combined the each of the two (-) leads for the left and right sides
> to match up to the harness (8 leads to 6 leads). Is it likely that
> the combining of these two sets of two leads from the radio is causing
> the amplifier to cause this static? Should I go back in and just wire
> the speakers directly to the radio leads?

This probably IS the problem; modern radio's use a so called "bridge"-AMP;
the negative output can get BELOW 0V (negaitve actually) due to some
internal electronic trickery. If you combine the negatives you force them to
work together. BUT when there's a difference in the "negative" outputs fro
fron and back you get a sort of feedback into the amp, causing a lot of
noise.

I'm quite positive that when you disconnect either the front or rear
speakers and put the volume over 15 the noise doesn't occur.
You should correct this mistake as soon as possible; not doing so
can cause damage to the end-stages of your radio!

I've done a couple of DeLorean re-fits now, as well as some other cars
and have allways used "ISO-plugs" on the car; a standardised set of
connectors for both power and speaker leads. Most modern (European)
carradio's have these connectors on them too, which makes putting in
a different radio in some future time A LOT easier.
I've allways put in a separate continous feed, fused at 10AMPs and on
the DeLoreans I used the original wire from the ignition to give the
radio that signal; the actual current draw should be on the continous feed.

It would be best to remove the 9-pin plug and wire the leads as the should
be wired; if you check the manual that came with your radio there will
probably even be a warnig about connecting the ground-leads together!

Good luck, mail me if you need more help,

JAN van de Wouw
Thinking Different... Using a Mac...
Living the Dream... Driving a DeLorean...

#05141 "Dagger" since Sept. 2000

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