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Re: Radio Question

Donald Fujihira wrote:
> Wolff wrote:
>      '91 200 tq with Sony sound (That was a fun install)
> I just replaced my head unit (in a 91 200Q) with an Alpine mated to
> the Bose active speakers using a Crutchfield interface.  I have two
> problems which were essentially nonexistent with the factory head
> unit.  I have (I think) alternator whine that is not particularly
> intrusive at higher volumes, but is quite annoying at low volume.
> Working with Crutchfield's tech support and trying to make various
> ground connections, I have not been able to eliminate or even affect
> the alternator whine.  I also get a loud crackling sound through the
> speakers when I turn the head unit off.  I tried installing a relay
> for the speaker and antenna amplifiers (at Crutchfield's suggestion),
> but it made no difference, and it sounds as though there is already a
> relay behind the dashboard for the amplifiers.
> Did (or do) you have either of these problems?  If you or anyone on
> the list solved them or has any suggestions, I would appreciate your
> comments.
> Thanks for your help,
> Don Fujihira
> 88 80Q
> 91 200Q

The popping/ crackling when you turn the unit on and off and the
alternator whine are the same problem. I don't know what interface kit
they sold you contains, but the input levels on the Bose speakers in
stock form need to be really low because they are amplified. Since they
are amplified, any signal (including alternator whine and powering up
transients) will be amplified. The solution is to remove the internal
amp of each speaker from the circuit and use the Alpine's amp if it has
   Problems with this are that my Bentley shows the internal speaker
amplifiers as active crossovers. My car had no tweeters, the manual was
wrong and it was no problem. However, somebody's car must have tweeters
or it wouldn't be in the manual right? :) If yours has tweeters, then
you will also need crossovers. Second problem is that you need someone
that can remove each speaker, disable/bypass each amp, connect the
speaker input wires correctly to the speaker, and put it all back
together without screwing up your car. I found missing bolts and gaskets
in my driver's door.

BTW, did the installer take my instrustions and only use the rear
antenna? It provides both an AM and FM signal, while the front is only