Hello, I've done a few searches and didn't quite get what I was going for.

After installing MTX Thunder 404 4-channel amp and Infinity Reference 6000 up front (didn't get to the back yet, still stock speakers with stock HU power), I'm getting engine noise. What a crappy way to end a day of work. Oh, MY04 wrx wagon.

I'm using the speaker-level inputs on my amp. To get signal, I soldered household speaker wire (16 gauge, I think) to a small section of the wire going to speakers (front only as of now) and ran wire down the sides then over beneath the backseat floor carpet. Power runs down the middle and for the most part stays away from the speaker wire.

But that doesn't seem to be a possible source because I tried routing power outside of cabin, avoiding signal altogether and noise is unchanged.

The amp's ground is good, 0.01 Ohms from amp terminal to battery terminal.

Noise is not present with speaker inputs unplugged and spare shorted RCA plugged in.

So I think I have tracked the source of the noise to between the HU and the point I spliced off of the speaker wire--ie underneath the dash in a mess of wires.

I know, I know, replace the HU, but I don't wanna.

Has anyone heard of or can guess any other possible sources of noise with this head unit/wiring setup? Any help would be great. Thanks!

 

that's a common problem with line level inputs. try a noise filter if you don't wanna change the HU. also, some LLI's come with the ability to adjust the level from the speakers to the amp. if you have one lie that , try turning the level down.

 

david navone makes cools LOCs and other noise muting products:

http://davidnavone.com/filters.html