King, where did you move your sub to/from. It sounds like either a ground loop issue, or possibly picking up some rfi from re routing the wiring. did you move the sub, or the amp or both? If you moved the amp, try grounding the amp where it was originally grounded. Also look at where you rerouted the wires. The signal lines should be routed away from any +12v lines to avoid any possible interference. When I mounted my amps in the back of the cruiser, I ran the power down the drivers side kick panels and the signal lines down the passengers side kick panels to avoid any kind of interference. If all else fails, there are a few noise filters available to eliminate noise through the power inputs . Here is a link to look at
http://www.partsexpress.com --> do a quick search on noise filters