hi all, iv just installed a 4channel amp into my coupe, iv run upgraded wire from the speakers to the amp so done away with the speaker cable on the wireing harness at the back off the head unit. i was only running the front speakers at 1st and theye where fine, went to do the 6x9s todays but when its all connected there is a high pitched skeeking noise comes from only the front speekers, whne the car is not running it doesnt make the noise, also if i run just rear or just front speakers it is also fine, its only when all 4 are connected i get the problems. any ideas what iv done wrong?
im using seperate rca cables, 1 pair for front and 1 pair for back, all speakers are indavidualy wired to channel 1 up to 4.
any feed back would be great