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 great 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 hit 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?

 

sounds like electrical noise. i knwo they make filters for stuff that doesnt use alot of juice ( like a head unit ) but i dunno if anything is available for something large like an amp.

 

Do you have your line level box/wiring anywhere near your power wires? Try moving the wiring around and see if the sound gets better or worse.

Those ground loop boxes have never worked for me. It's a nice idea, but the right way is always where the pay off is.

I've seen voltage regulators in the alternator go bad and create that condition too. You might want to run a good alt test and see if anything is abnormal.

 

that popping noise is normal in the mach systems as I have it in mine. It is annoying but doesn't hurt anything.

Somebody on here once said that putting a 1k resistor inline with the remote wire worked but that is bs, didn't help anything.