Noise in 350z

Anyone had problems with noise in the 350z? I am having a problem with noise sounding like an old dial-up modem, very low volume, through the speakers. Pioneer head, Crossfire 404 on sep MB Quarts, Rockford Power1000d on subs, Rockford Phase3 subs, Crossfire x-over, Esoteric interconnects. I have exhausted every idea I can come up with as far as solving this problem, I am an installer with 19 years of experience, so I'm not even close to inexperienced. I'm starting to suspect the car has been damaged some way or the electrical system is just that noisy...anyone? time is bending.....

could be a number of things. bad ground, rcas run next to power wire. Id check all of your aftermarket wires and check the resistance of all of your grounds.

I'm assuming since you are experienced you have gone thru all the standard noise reduction procedures.I had a similar unsolveable noise problem on a Civic SI last year. Turned out the passive crossover from my components was to close to my main power lead and very low level noise was bleeding into the crossover itself. It's a long shot,good luck.There is no such thing as free installation!

Try grounding the outer shield of the rca's at both ends.  Also try bypassing the Crossfire crossover.  Just to add to Bob's crossover idea, also make sure the crossovers are not close to any onboard computers/control modules.My ex once told me I have a perfect face for radio.

The noise I'm getting sounds like computer data, it doesn't change with engine rpm's. I did notice that it seems to show up when there is a draw on the sytem. I have replaced the alternator, ran rca's outside of the car, replaced the crossover, the amp on mids and highs, the head unit, and even upgraded the grounds on the engine block. I checked for grounded speaker wires, and checked the resistance between the battery and ground in on the amp, 0.07 ohms. I think even David Navone  would be baffled by this one.....time is bending.....

I got it, some neurosurgeon had put one of those ground cable engine wiring thingies in the car, tied all grounds together on the engine, then grounded the engine block to a very solid connection on a piece of plastic. I ran a piece of 4g to the buss bar that was mounted to the plastic, and, voila!, the wonderful sound of silence.....time is bending.....