Well after fighting health issues, snow, freezing cold and rain, I finally got everything in and hooked up. However, it sounds like crap! On the front and rear channels I can only get the gain up to about 1/3. On the subwoofer channel it's turned all the way up and there is still very little bass! The front and rear channels sound really distorted. I went back and checked everything and the wiring is all good. Everything on the HU is set flat. On the Amp the front HPF is off because the passive crossovers are being used. The rear channel HPF is set to 120 Hz. The sub channel LPF is set to 120 Hz. No bass boost and the subsonic is off. I already verified the RCA's are correct. The only thing I'm not sure of is the front speaker wiring. Rather than fighting a wire through the door conduit, I just ran the wires from the amp to the HU area and connected them to the factory speaker wires. I had it written down that the white (+), white/black (-), gray (+) and gray/black (-) are the front speakers. When I use the balance/fader, it works as it should. I've tried to find a wiring diagram for my truck but for some reason everything I find is for an amplified system or a different vehicle. I'm 99% sure I have it right but would like to be 100%. Anyone have a diagram for a 2007 XLT, non-amplified, radio?