Please help me figure this out. Sometimes, my system sounds great, with good bass, mids, and highs and other times it sounds lifeless (like a poorly recorded track or highly compressed Mp3). If and when the change occurs, it's related to vehicle start up- in other words it may play great and continue to do so for the entire drive, then I turn off the Jeep, and the next start or a few starts later, it sounds like someone screwed all my Eq settings. It does not matter what source material is playing-usb, SD, Bluetooth, etc, and even the same song that normally sounds good can sound different at different times.
I have swapped all speakers (different brands) 3 times, all amps have been changed out 3 times. I went from high level inputs direct into amps, changed to an LC2i and Clarion Eq, to a DQ-61, and now a Dayton Dsp-408. The only thing that hasn't changed (and I'm stuck with) is the Uconnect head unit in my 2015 Jeep Grand Cherokee (non-amplified). I've never had this problem before, but I've always replaced stock head units for aftermarket. I realize process of elimination points to the factory head unit, but in the off chance it isn't defective, is there something I might have missed?
Some people say they need load resistors on their uconnect speaker level outputs in order to get signal to the LOC, but mine is still able to put out a signal without errors. The only other thing I can think of is the wiring splice from the factory speaker harness originally run to the high level inputs of the 1st amp I had originally installed. It was done by an installer and is the only other thing I haven't redone. I noticed a couple of those wires smashed flat when the rear seat was lowered and bolted down. I have since repositioned them. I can't imagine that to be the problem, but at this point, I'm hoping for something that simple.
Anyone ever have a similar experience or be able to explain possible causes? Would those smashed (but intact) high level speaker wires affect output voltage going to the LOC enough to cause my issue? When my system acts up, I do have to crank the volume to compensate. Please and thank you for your help.