I have an 06 FX4 with the audiophile also. I hooked up the d3 and it sounds just awesome. i still need the resistor though to r=get rid of pop. if u are using the correct harness( should be 2 of them, one for speakers, power etc and one for the sub) the sub harness should have a set of preouts and 2 blue wires. the one blue wire is not connected to the oem harness, so check to make sure the correct one is wired to remote turn on the head unit. i found this out myself as i initially didnt have sub hooked up either. also play around with the staging option, i have mine set on dynamic, and