ECU interference on door speaker

[Ameer Antar]

Thanks for the info. Unfortunately, I already have everything setup that way. I have a ground cable directly from the batt to the a splitter and then onto the amps. While I had the carpet out, I also ran a ground cable from the batt under the back seat to the engine grounding point. I'm not sure if that was a good thing or not, but I haven't seen any other problems. The noise really got worse when I bolted down the ECU to its bracket near the wire grommet for the right front door. I will try adding a cap to the amps, but I doubt this is an issue. The noise comes over loud and clear even with the volume at 0. As long as the stereo is on, the speaker picks up the noise. Very strange...
 
-Ameer
 
-------------------- Original Message --------------------
From:Scott Phillips [Scottp at ippe.com]
To:Ameer Antar [antar at comcast.net]
Cc:quattro at audifans.com
Date:12/12/06 12:27:26 PM
Subject:RE: ECU interference on door speaker
Ameer..

This is only related to your post, but may provide insight.

In Control wiring the cabling includes a "drain" wire; the drain is
attached to a ground at each end to help eliminate interference from
affecting the signal in that wire..

In your specific case I would suggest (if this isn't the case already)
running a ground wire directly from the battery to the Amp. And look how
the amp is mounted; isolate the case of the amp from the sheet metal of
the car (don't use a sheet metal screw thru the amp mount into the car,
mount MDF to the car, then the amp to the MDF) and you should be okay.
Another thing to add would be a Isolation Capacitor of .5 Farad or 1
Farad to provide the amp with "reserve" for times when it needs it, it
may be drawing too much on the car's electrical system (and the speaker
interference that your noticing, could be an indicator of that)

HTH..

Scott

-----Original Message-----
From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com]
On Behalf Of Ameer Antar
Sent: Tuesday, December 12, 2006 11:11 AM
To: Quattro List
Subject: ECU interference on door speaker
Hello all,
I've just installed a new ECU in my 5000 turbo. I strated to notice that
I'm getting a lot of interference from it on the right front door
speaker. I actually had to route new speaker wire near the ECU to get to
the speakers becasue the car did not originally have door speakers. Has
anyone else had noise issues with that speaker?
I did a little troubleshooting, but now I'm stumped... I figured if I
disconnect that speaker from the amp, I'd be OK, but it just moved the
noise to the rear speakers. What's also strange is the noise is really
only audible when the headunit (and amps) are on. I tried disconnecting
the amp for the door speakers (power and audio cables), but the noise
just went back to the speaker near the ECU.

It'll be difficult to reroute the wire the way it is under the carpet.
Is there any shielding that might work on this? Thanks.

-Ameer