static on front RCA's

Need some help.  I've been scratching my head over the weekend and could end up bald over this.  I have a Pioneer deck/two amps (rockford) a set of focal's comps up front /6x9 in the rear and a 10" sub. 

Here's the trouble I get a huge amount of static in the front speakers.  The rears are clean(deck power).  when I run off the rear RCA off the deck the front speakers sound fine.  What am I missing.  I have tried new RCA's/different amp/different deck(same results  on front RCAs lots of static-rears clean)  Tried new grounds, nothing seems to help. 

If you have any ideas that I'm missing please let me know.

Pioneer head units are notorious for bad internal ground planes that cause noisy line-level signals.  Try adding a ground wire to the outer ring of one end of the RCA cable and connecting this to chassis ground.  If the problem stops, your HU is defective.  If it's under warranty you can send it back for repair (include a detailed description of the issue) or you can simply operate with the ground wire connected.  You shouldn't have to do this but it won't hurt anything.

It is also possible that the location of the front speakers, crossovers or RCA cables is such that they are picking up noise from the electrical system in the vehicle.  You might try unmounting everything and laying the speakers and crossovers in the front seat and running an RCA cable across the seats to the amp to see if the problem stops.  If relocating the components helps, then your amp and HU are OK and it's simply an installation issue.