I recently been having problems with my system. I hear a loud crackling noise that comes from my components (no crackling from sub) when the car is moving, especially over bumps and uneven payment. The crackling sound is absent when the car is still. It produces itself when the headunit is in FM and CD mode, even when the volume is all the way down at zero. When I put the unit on standby, the crackling goes away. The weird thing is that the system never had this problems before.

I took apart my whole system yesterday and still can't figure it out. I checked the polarity of the speakers, all connections, crossovers, and the amp. No visible kinks in the speaker or power wires. I disconnected the components and hooked up some coaxials and I still hear the noise, almost ruling out that the speakers are not blown. System is properly grounded and everything else seems/looks fine.

I've installed many systems and never had any problems. This one has me stumped. If anyone has suggestions, please feel free to post here. All help is greatly appreciated. Thanks in advance.

 

Possibly a short in a wire somewhere? That would be my best guess seeing as how it happens mainly over bumps. I had a similar situation but with my fuel injectors. My car would run extremely rich right around 3000 rpm. Turns out one the wires on #3 injector was grounding out and my engine vibrates the most at that rpm.

 

Triple check the ground on the amp and headunit. Report back. (sometimes, grounds look ok, but bumps will show otherwise.)

 

cracking could also be the rcas if you have something running the fronts... go to the back of the amp and shake the rcas to simulate "bumps" if you get a crackling... there ya good :-)

 

Well I re-grounded the headunit and the amp and the I'm still hearing the cracking/low hum noise. I tried shaking the deck's wiring harness and the rca's, but that didn't seem to make the problem any better or worse. The noise disappears only when I put the deck on standby or if I unhook the rca's from the amp (no signal to headunit/components). I tried switching the rca's from one output to another and the noise is consistent.

I'm really pulling my hair out on this one. If anyone else has any ideas, please feel free to chime in. Thanks.

 

When the deck is on standby do the amps still have power?

 

you may want to try using a different source altogether to narrow it down... i.e. use a Ipod or something with an adapter cable: minijack at one end, rcas at the other. Plug that into your amp; leave the remote wire intact. Or give it +12v some other way, doesn't matter. If the crackling sound still exists, the problem is either your amp, speakers, or wiring. If the crackling is gone, the problem is either your head unit or rcas.