I have a 2011 Titan pro 4X. I've wired up systems before to stock radios, after market radios all of it. I recently installed a preloaded amp and subwoofer box to my stock head unit. I used a LOC that I used on my older frontier in the past. Wired the loc to the head unit exactly as I should. No out of phase wires. Even triple checked myself since this issue. Read online that it could be bad RCA's so I went and bought a second set plugged them in same thing. Subwoofer moves with both RCA's plugged in but almost no bass. Disconnect one RCA from amp and the subwoofer gets five times louder. checked my ground everything seems to be perfect except for this RCA issue. Anyone got any ideas?