Originally Posted by caneman88

I'm doing the upgrade right now with factory nav having issues with the output of the HU getting clean signals
I've had 2 Alpine amps installed 1 PDX 4-100 bridged powering the Focal 165 KP front speakers and a Alpine V-power mono 300 watt powering the JL 10"sub but something doesn't sound perfect as it should with the upgrades still working on it. Custom Sounds and I have about 32 labor hours invested.
They seem to think there is some DSP chip built into the HU so not as clean as aftermarkrt unit. I had a 06 Civic w/factory Nav did the same thing and it rocked.
Not sure what to do now keep tweaking? JL audio make a product call clean sweep takes all signals from factory HU to flat and work up from there.