I have just installed a JBL P80.4, this is a 4 channel amp, my headunit only have one pair of preout (stated "front out" behind headunit).So I split the preout into 2 pairs and plug into my amp front and rear rca input. After the installation, I got everything working. But when I start my car and turn my headlight on, there will be a high frequency pitch sound coming out from my speakers, it will get louder as i rev my car...it only happens when I start the car and turn the headlight on, it won't have any noise when the car is started and the light is off, or the light is on and motor is off... can any one help me please?? Is that the earth problem or something else??
No, its deffinitly an electiral noise problem. Are your signal cables close to the amp's power cable? Is the amp mounted close to the firewall? IS EVERYTHING PROPERLY GROUNDED!!!?
hi josh,i place my amp under the front passenger seat,my power cable runs along floor door sill of the passengers side under neath the carpet, and my RCA and speakers wire all runs from the center to amp. I screwed my earth of the amp to one of the screws at the center location(underneath the armrest which is metel). But I didn't scrap any paint off.. is that matter? Is my installation ok? Thank you man!