I posted over at FNSweet.com as well but here is the same posting:

"I bought the car with an aftermarket JVC head unit (http://support.jvc.com/consumer/prod...3&archive=true) hooked up to the Mach460 system. The system isn't the easiest to use and I was just figuring on getting something different (possibly touch-screen and nav) but to be really honest, it does have a lot of nice features: Bluetooth, in car integration with the speakers for hands-free mobile use, USB, DVD capability. The head unit appears to be hooked up to an amplifier in the trunk but there is no subwolfer and, without ripping the door panels off, the stock speakers seem to be intact. Maybe the previous owner had as much luck with the stock head unit on my Stage 2 and the 6-CD changer was always getting jammed.

First thing, first, the USB cable was never exposed. I had to take the stereo out and address that.

Secondly, I was getting plenty of interference with the motor running. I bought two filters and hooked them up during the amp and it did eliminate most, but not all, engine noise.

In the end, though, I just don't think it sounds too great. Granted my Mazda had a Bose system in it from the factory, but I recalled the 460 sounding better than it does. When moving the fader to the front speakers it sounds much quiter / more distant than the rear speakers, and the whole sound profile even with the bass up the whole way sounds kind of flat. It seems to be fine for chilling out with the 2-year old in her carseat and Veggietales, but not so great for a rock fan.

Maybe it's installed wrong. There are a ton of cables running into this bad boy. It appears to have been professionally done, though. Maybe others have experienced the same behavior -- all of my Mustangs before had the stock head unit. Maybe it's just my imagination stepping down from the stock factory stereo of the Mazda.

The best music is to just turn it off.

I am looking to see if anyone has any insights, though. Better yet, if anyone is in the somewhat local area and knows anything of this sort, maybe we can meet up. I'll buy you a few drinks in exchange for some advice."

Thanks!

 

I don't have any real in-site's for you except that I get the feedback from the engine too and it drives me nuts, but besides that I'm happy with the system... certainly not up to par with my 07 Shelby, but we're talking 11 years difference in technology.

 

make sure your power cables for the amp, and the signal cables are on opposite sides of the vehicle.

My power cable runs down the drivers side under the sill and rear seat. The signal cables run from the amp up the passenger side.