Ok, so I installed a boss phantom 3700 5 channel in my car (I know, boss is generally garbage but I got a decent deal on it) anyway when I turn the key to battery on there is a slight hissing sound which only occurs when the input sensitivity is set to 200mv setting and goes away when I select the 2v to 8v setting, but I'm using RCA inputs so I would really like to use the 200mv setting as it is much louder. When I start the car there is static noise which is extremely annoying, this gets louder as I raise the volume, the hissing stays a constant volume no matter what volume the HU is set on. I don't believe it is a alternator issue as it doesn't change pitch with rpm. I have the power wire to amp on the driver side and the rca wires on passenger side, to try to avoid interference. Could this be a grounding issue? Any advice would be great.