Phyrus00

Car: 93' 90cs

Recently got an aftermarket headunit installed (50X4 MOSFET) and ever since, there has been a high-pitch noise coming from the speakers whenever the radio is on. The noise gets louder whenever I accelerate. I was told that I'll have to bypass the rearamplifer by wiring a new speaker wire from the headunit to the rear speakers.

Is this true? Will I have to lay new speaker wire to bypass the amp? Or is there a way to just "turn it off".

Any help is greatly appreciated.

johnny12v

Engine whine is ground associated. YOU MAY NOT HAVE A GOOD GROUND ON THE HEAD OR THE GROUND POTENTIAL IMPED. IS DIFERENT BETWEEN THE HEAD AND AMP.
If there is an amp which I don't know. You are overloading the imputstage. BUT why does this not affect the front amp.
Most of the Blau heads have built in power so I doubt there are external amps.
Does the noise only happen with the radio.?

Most new vw / audi need a special antenna adapter because of the powered antenna did you buy one.

sorry for al the jumbled thoughts but here are some things to think about.

Phyrus00

I did buy a vw powered antenna adapter. The engine whine affects the radio/cdplayer/mp3. From what i've read, only the rear speakers are amplified and the front speakers are powered by the stock HU. So mabye I could try disconnecting the rear speakers from my HU and see if thats a factor? Also, when it was installed, it was hardwired because there was no wiring harness for my model (93' 90cs), so mabye the ground wire is too small where it can't handle the power my HU is sending out. (HU is Pioneer DEH7400MP, Mosfet 50X4). Thanks for any suggestions!

JustJeff

<ul><li><a href="https://forums.audiworld.com/audio/msgs/20114.phtml">Noise filter</a></li></ul>

Phyrus00

Can I purchase a noise filter from a store instead of making it?

JustJeff

Yes, Rat-shack has a few in different wattage-sizes