I recently bought a Ford Explorer which had a Pioneer head unit and Ford factory speakers. I took out the speakers and installed some Polk's that I had from my old car and it sounds absolutely horrible! I have never installed anything on my own before, so I don't know if possibly the wiring is wrong, or if I just need a new head unit or what? Any ideas? I get really bad low-end distortion on any remotely high volume, but my high-end sounds great. The wiring is done with electrical tape, no harness. Does this matter, and is the wiring just pos/neg or does one wire go to the tweeter and the other to the cone? Sorry for all the questions. Please help if you can!