ECU interference on door speaker
audi at humanspeakers.com
Wed Dec 13 14:21:39 EST 2006
> I removed all the RCA cables from the amps and tried revving the
> engine, but the sound is still there, mostly on the right front door
So the sound is independent of the RCA wiring, is it RPM dependent?
> I know it's crazy, but I'm still suspecting that speaker
> wire near the ECU.
It won't be. OK, unless that wire is actually *connected* to something
other than the amplifier, like via some scraped insulation.
Try this... disconnect all the car speakers at the amp. Run one speaker
wire out of the car to another speaker, any speaker. Turn on car, fire
up and listen.
Just a quick thing that occurred to me but I dismissed since you are
running your own amplifiers - those door speakers do not have built in
Also make sure the speaker wire is not accidentally grounded anywhere
along its path, especially in the door, at the speaker.
> It only comes over the tweeter which is probably
> more sensitive to interference.
Nooooo, it's because the noise is mostly higher frequencies.
Also, the passenger door speaker is often the easiest one to hear when
sitting in the driver seat. I'll bet it's equally present on all four
Keep trying the hints people have provided here to stop the noise from
being picked up at the amp; also anything you can do to reduce the
source will help.
If it is RPM dependent, it may be alternator noise, being broadcast
through the alt to battery wire. Brush condition? Quality of all main
power system grounds? It may also be ignition noise - check quality of
plug wires, cap/rotor/plugs, etc.
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