Hey everyone. I have a 2003 mustang gt with the mach 460 sound system. I added an amp and 2 subs, using the line-out converter. Everything was working good for a couple weeks until a couple days ago a random sound started being produced. It only came out of the subs when the engine is on. Its not like a popping or anything, it sounds like a beat. The pitch and frequency of the beat is changed when i hot the brakes or use the power windows or turn my headlights on. Its not coming from my radio because if I take the rca inputs off of the amp the sound is still made. Also, if i have the windows up and i hold the button in the 'up' position it stops making the noise if i am at rest or braking. Also, having headlights on and the rear window defroster will stop the sound for a while. I changed where it was grounded, no luck. Ive also asked a couple of professional audio shops around but then want something like $60 an hour to even look at it. Any ideas?
are your rca wires runned next to your power wire? If so, run your power wire on your passenger side and run your rca wires on your driver side, or vice versa. Make sure your rca's aren't close to your power wire basically. This causes unwanted noise.
Its a ground Loop. Ground both amps to the same spot. If that dont work, try a ground loop isolater on the rcas. Not the best solution, but its easy and may work.
I eventually found this audio shop in New Orleans called Kaoss Car audio and the guy came out and checked everything. We moved the ground location again and moved the location of the amp, and checked the wiring of the subs. The subs were producing a weird 7 ohm resistance, so we re-wired them, and all is working. He didn't even charge any labor. So if you are ever in New Orleans, go to Kaoss...They're the place to go to.