I put keywords in the title so anyone doing this project would read this.

I put in a full new stereo and had a month of hell looking for a ground loop or other dirty power issue. What did the trick was a switched out my amp. I originally put in a Class D. I borrowed a friend's class A/B and the hum went away. I then purchased a quality A/B and my problem is gone. I did find from reading that many people do believe D is more sensitive to noise, and my issue was in line with that.

Do your self a favor and just start with an A/B.

I am not going into the difference here, tons of info on that with a search.

 

Thanks for the info. I have been chasing this for weeks. I OHM'ed out every ground and they were all good. Put in filters and never could get rid of it. Sounds a little better but it is like the is constant "snow" coming from all of the speakers. All three of my AMPS are Class D. Now going to have to spend another $600 to see if that is my problem.

 

Good luck. what head unit do you have? As I dug in some more my android head unit was also problematic. Just make sure you can return anything you buy.

 

It is a Kenwood BT 705. I really don’t think it is the head unit. If I unplug it from the amps I get the same noise. Yea I use Amazon so will return the amp if that does not fix it

 

Did you try powering the speakers directly from the head unit amp.

 

I have not tried that, but that would be a pain in the butt since all the wires are in the trunk. I guess that would be a good test, though. You know, where Jaguar decided to put all the amps and the equipment in the back was a good thing and a bad thing. The good thing is that it is close to the battery and easy to run power cables. The bad thing is that they put everything by the battery, and you can get all kinds of power noise from that area. That is what I think it is. I tried to upgrade the cables. I tried to relocate things, yet I still have the same problem. I took a multimeter to everything, and everything checked out. I think the last option is to change out the amps. Not running anything through the AMP and still getting noise on the connected speakers has been a pain to figure out. I am nearly dropping it off at a sound store and letting them figure it out.

What is interesting is that the noise is very weird. Yeah, you hear like white noise. However, in the background of that noise, you can hear what sounds like Morris code. Although my antenna is not powered on at the time, I think it is picking up something and amplifying it onto the car stereo. After all, everything that is stereo-related, other than the head unit, is right there in the same place

 

Not sure what might be interfering with your system but l certainly don't think battery has anything to do with it. I run a JL Audio XD700 5 chanel in the OEM location via speaker level input from Android and sound is very clean.

 

After doing some research I read a lot about making sure your Stereo, amps, and DSP are all grounded to the same location on the body and I managed to get rid of some of the noise but the alternator noise is bad. So I ordered a couple cheap noise filters and will see if that is the problem. If that does not fix it I am at a total loss and will pull everything and start over. One good thing came out of this, I can now pull the stereo back seat and take the trunk apart in record time