Audio Systems: GM Bose System High-Frequency Noise!, gmc envoy xuv, gm bose

Question
Tom,

Thanks for checking back with me.  If you can believe this, they still haven't been able to resolve
the problem.  The dealer has replaced nearly every component in the car, installed filters and
noise suppressors, re-routed the wires - just about everything you can think!  But nothing has
worked.  For now I am forced to either "deal with it," leave it off, or turn off the rear speakers by
activating the back-seat headphones.  I'm not too happy, as you can imagine.  Will let you know
if it ever gets fixed.

Thanks!

Brent

-------------------------
Followup To
Question -
Hello.  I recently purchased a new 2005 GMC Envoy XUV with the
Bose Premium Sound AM/FM/CD/Cassette option.  (It also
has the rear-passenger radio & climate controls.)

The problem I am experiencing is a very high-frequency noise
emanating from the rear speakers - but ONLY when the engine
is running.  The noise does NOT vary by engine speed.  But it is
constant regardless of the source and regardless of the volume
level.  It is difficult for some people to hear but becomes obvious
once the engine is shut off (and thus becomes noise-free).

My dealer doesn't know what the cause could be and has
replaced almost all components of the radio system but still the
noise remains.

I could hear a similar sound from outside and underneath the
vehicle and theorized it could be another electric component
that is somehow bleeding in to the radio system.  The dealer
confirmed this and replaced the fuel pump which took care of
the outside noise but the radio noise still remains.  They don't
know what to do at this point.

If you have any ideas or suggestions as to where we may turn, it
would be much appreciated.  It's a really good sounding system
with the exception of this very irritating problem.  Thank you!
Answer -
Brent,
I'm following up on the noise problem with your vehicle and I would like to know if you or the
dealer solved the problem and what was the cause of the noise in the speakers?

Tom,
T&D ELECTRONICS
tdeser@zoominternet.net

Answer
Brent,
I beleive I found what the noise in the rear speakers is coming from. The Bose amp is a high powered amp which operates on approx 40 to 50 volts DC, this operating voltage is generated by a DC to DC convertor inside the amp. The output of the power convertor must well filtered so you won't hear any ripple in the speakers. I have contacted Bose and they will be getting back to me in a couple of days with a cure to the noise problem. As soon as I hear from them I will let you know.

Tom,
T&D ELECTRONICS
tdeser@zoominternet.net