rca static only when i use 4 channels

hey guys im running an alpine HU with DEGO components both front and rear powered by a VDO amp. i have a sub aswell but theres no issue with that section of the system. heres my problem. when i first installed the system i had quite an annoying static noise soo today i decided to try i isolate the problem. ive followed all the guide ie moving the ground around and everything. what ive concluded soo far is that if i run only 2 channels ie only the front speakers i dont get any static, ive swaped different rca's and ive tried running only the rears and its the same. As long as i run 2 channels theres no noise. once i run the full 4 channels i get annoying static. this is the first time ive ever come across a problem like this. any advice would be very helpful thanks

What do you mean by "static"?  Are you hearing alternator whine - does the sound change with the engine RPM?  Does it go away if the engine is off?  Or are you hearing static-like noise coming from the speakers that is the same no matter if the engine is on or off?Support the12volt.com

hey its not alternator whining. its more of a light hiss. just very annoying when theres no volume and the windows are up. soo far ive ran channel 1 and 2 individually with no static. 3 and 4 individually with no static ive used a splitter from channel 1 and 2 from the HU to open 4 channels on the amp and there was no static I only get static when i use 4 channels from the HU to the amp soo i reckon it must be a HU problem. the aircon is right behind the HU but i dont think its that because when i run RCA's on the outside of the car and the HU its not in place i still get static.

If you turn all of the gain controls all the way down, does the noise go away?

yup it does.

Turn the gain up till you hear the noise again, then back it off a bit.

i am an idiot wrote: Turn the gain up till you hear the noise again, then back it off a bit.

Yup... This... I had the same problem with my 4 channel. You might need to either step up to a larger 4 channel if you're not happy with the volume settings with the gain being lower... or you'll need to get a head-unit with higher voltage pre-outs to help control that noise floor.

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