Alright I have a weird issue. I have a JVC Head Unit hooked up to a Pioneer 300 watt 4 channel amp and feeding 4 sony xplods 220 watt speakers. The Head Unit is connected to the amp via rca cables. One for the front set of speakers and one for the rear. When I have the front rca cables from the head unit connected to channel A of the amp which is connected to my front speakers and the rear on channel B I get a hum that follows engine rpm. When I reverse the rca cables the hum goes away. Any ideas. Basically everything is backwards right now. Not very noticeable but it would be nice to have them hooked up correctly.

 

Most amps that I know of, regardless of how many channels, only need one set of rca cables to hook them up. I don't know why you would need two. I have not seen any amps that have two sets of rca inputs either. Something seems strange to me. Well, good luck with the problem.

 

The amp is a four channel therefore has four inputs. Your solution is very simple. Since the hum is gone when the rca are hooked up backwards, just hook the rear speakers to the front channels and fronts to the rear. The noise is related to the input. You have a ground loop somewhere. The amp doesn't care what speakers are hooked to what channel.

 

Check the ground on the amp, make sure you have it in a good place. Also check your rca's, you might have one bad. If you bought cheap ones, then that might be the problem also. Did you run the rca's down the same side of the car as the power wire and remote?

 

Any four channel amp I have ever seen has four inputs. One set for the front and one set for the rear.

 

Also make sure your gain isnt all the way up, play with that as well to determine if its an issue.

 

Hey what's up man. I am a car audio tech from best buy. Maybe this can help. I had the same problem. What I did was check my power wired connections at the battery, the power line fuse from the battery, and the connection at the amp itself. Check to see that the power wire is secured properly and that none of the wire is sticking out or is loose. If you have it loose or not properly connected, some of the voltage through your power wire will escape and interfere with the amp signal. Also make sure since you're running a four channel amp that the power wired is routed the opposite side of the RCA cables. Reason for that is because some of the voltage will catch onto the RCA cables and cause the engine noise. If none of that works, then go ahead and purchase a couple of ground loop isolators and hook them up to the amp where the RCA's are suppose to go. If that doesn't work, then either it could be the amp itself, your headunit, or one of your RCA cables is whacked out.

 

I used to have this problem in a old car of mine, it turned out to be a bad ground spot, I ended up having to ground on the body, and run a wire directly to the battery negative post