I just installed a Kicker ZX350.4 brand new and four 6.5" Infinity Kappa Coaxials in a 2000 Jeep Cherokee Limited (with Infinity system, but I've now totally buypassed it with a Pioneer Premier Head Unit (4 volt preouts). BUT........ Huge Problem. My speakers whine soooooo loud. When i rev the engine, it gets faster, but when I turn the speaks up loud, its drowned out. Car off....amazing sounding speaks. I checked the grounding. (0/1 gauge from a brand new mopar battery, nothing special, just new. Stock alternator. The 0/1 goes to a stinger distrubtion block and 2 4 gauge cables go to my hifonics 1206d and my kicker 350.4) all the groundings good, rcas dont touch power, speaker wire doesnt touch power....but i have nooooooooo clue what the hell is wrong. A guy I know who installs this stuff for his job at a custom audio shop did most of it for me and said it could be the amp. What do you guys think?