4 channel amp having issues

Hey everyone! I hope someone can help me with a noise issue. My system has been working flawlessly for about two months. Then last week the problem started. I noticed that my drivers side door speaker stopped working and I was getting a high pitched noise through the rest of the door speakers. I took off the drivers side door panel and noticed that power window had pulled one of the speaker wires off of the speaker and stripped the insulation off about two inches causing a dead short to chassis. So I took the speaker out, fixed the wires, reconnected the speaker and the speaker started working fine. However, the high pitch noise still remains. I also noticed that with the ignition on there is a slight hum now and when the car is running the high pitch noise starts. Another thing to add is that when the amp turns on, there is a slight pop in the amp and then the noise starts. When I unplug the RCA from the amp the sound will go away. The other crazy thing is when the amp is on and i disconnect the first two speakers from channel one it will make a god awful squealing scratching sound through all the speakers! Also when turning up the volume the high pitched sound does not get louder as the volume is turned up but the high sound quality is definitely gone. Meaning the crispness of the mids and highs. The sub amp is fine. So the amp with the problem is a rather expensive Mmats Pro Audio SQ4160. I sent it in and they called me saying that the amp is making its rated power and works fine. Then when I explained the crazy squealing issue when the left channel speaker was unplugged and the amp makes a pop when it turned on they said that they were going to do a further test. So now that i have explained this in great detail and probably bored you all to death, lol.......does this sound like the amp is having the issue? I do know a lot of noise can stem from head units, grounds and RCA's. In the meantime while waiting for my amp, I have checked all of my speakers impedance as well as any shorts. Everything looks great. Since the speaker had a pretty significant short to the chassis could it have caused the amps output to have gotten screwed up? Sorry again for the long winded question but its killing me! lol Thanks again!!

At what number of your volume control do you listen to it? Have you tried turning the gains all the way down on your high amplifier to see if the noise goes away?

Well I really don't blast it very often. Just medium listening mostly. I do have the head unit set at 32. At 33 is when distortion is present. I set the gains using a DD1 distortion detector. Yes, if you start to slowly turn down the one of the gains the noise will start to diminish.

Jeffster1978. What head unit to you have? since the noise goes away when you unplug the RCA's, I would start looking at the source unit.

Here is a link for further information:

https://bcae1.com/images/rca/temporaryrcashieldrepair.html


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I have a brand new Kenwood 892 touchscreen head unit. I just did a continuity test and everything looks good. I just got off the phone with Mmats today and again he said nothing was wrong. He told me that it had to be a set of RCA cables that went bad or the head units ground. They are sending the amp back to me today so when I receive it I'll check the RCAs and then pull the head unit back out. Also something else I just thought about...I have a back up camera that I installed. And recently it quit working. The backup lines come on the screen but no video. I distinctly remember that the cameras RCA didn't seem very snug when I plugged it in the back of the head unit. So I bet it worked its way out from the bass. And if that's the case...if the cameras RCA came out and has been touching chassis ground could that be causing noise??