I have had the same amp and sub for a year or so and they have been hooked up in my car for a while to the stock radio. I just bought a knew Kenwood DDX7017 head unit, and when I plug RCA's from amp to sub I get a constent thump like a heart beat from My sub CaN Anyone Help!!!!!
so you put in a new CD player and it started doing this?
it could be the preamp on the HU. (do you have an extra set of RCA's your willing to cut up? if so, i'll tell ya how to make a muting plug and see if its the HU that causing this)
also, if you used a wiring harness to wire up the HU...try regrounding the HU. (dont use the harness for the HU's ground...just disconnect the HU's ground and run it to a bolt somewhere)
also, are your RCAs run next to your power and ground wire on the amp?
The best advice you could get came from Marshall, check the grounds and the RCA's. Also make sure you don't have the hi level (speaker wire inputs) and the rca's hooked up at the same time.
My rcas are not touching any of power wire, our ground wire. I havent checked the ground for the Head unit yet because its a pain in the *** to pull it out. And yes I do have extras sets off RCA's. Thanks for your help