i have a sony CDX-M670 head unit that i am having a little problem with. when i plug my rca cables into the sub out jacks of the unit i get a whoomp sound and everytime after if i change the station put in a cd it has a single jolt or pulse that makes my subs react like i am touching the cables to other metal or something. also if i turn the volume all the way down i get noise like i have a bad ground (alternator noise). i have had the rca cables looked at to see if that is the problem but they checked out. also if i plug the rca cables into the rear of the deck to the front back left right rca jacks the subs are fine and there is never any noise or feedback. i have just recently removed the cd player amp and subs from my other car from which everything worked just fine. by the way i have a rockford punch 500 a2 amp and 2 kicker competition 12's, running a 4 gauge power wire in a 95 ford mustang. i wouldnt care so much if i could control the subs in some other way but listening to the radio with the boom boom just isnt what i want. help me out