Noise Problem, Yet Another!

Hi, My previous configuration ran fine. It was there when I got the car (200SX Nissan S13). I was running RCA cable from the front LR outputs from my Pioneer headunit to the boot where my Rodek amps is. The Rodek amp powers the sub but it also provides a RCA loopthrough my other amp (JBL) that powers the front L-R speakers. This was running fine. Until of course, I decided that since the headunit has a RCA read L-R/sub output, I wanted to have the headunit front L-R RCA to the JBL and the rear LR/sub RCA to the sub so that I can control the HPF available in the headunit without cutting out the bass to my subs. Sad to say after I did this, I noticed that I cannot increase the gain on my sub amp too much as before because I noticed that the sub itself was vibrating up down pretty high and low! So I put the gain really low. I thought everything was fine but when I started the car, i hear very loud while coming from my front LR speakers. I can still hear it with the headunit volume turned all the way down! apparently it has no effect on the while at all. So I reconfigured everything back to the way IT WAS when I first bought it and the whine is STILL THERE! Funny thing is the whine goes away if I completly disconnect my sub amp power supply. Got so frustrated that I removed my subwoofer (amp's still in the car) and totally disconnected the supply to the sub amp. Now I am running direct from headunit front L-R to the JBL amp. No subs. Whining is very very faint now but still noticeable when there is not much traffic noise..... Beats the hell out of me figuring this out....can anyone suggest something to help out?? Thanks!

Also if you have not already tried this cut your amp wire to no more than 2 1/2ft and reground it.  Also check to see if when you connected it that some how you crossed your RCA 's with a high voltage wire in your dash somewhere. Cheap RCA's if thats what you have love to find noise.Fatgotti    Yeah my name is John and I am FAT!! YEAH BABY