Static Noise From Subwoofer - Not Alternator Noise - Help!

defragme · December 17, 2008

I have a question for the audio guys. I have a Kicker zx350 amp running a 12" kicker cvt sub in bridged. It sounded great for about 6 months, then all of a sudden I started hearing some static noise coming from the sub when the headunit was either off or at very low volume. I was running low pass on the amp crossover, so the static sounded like thunder. When I switched it to high pass or off, there was a THUMP and then you could hear the full range of the static noise.

It still hums with the engine off (ignition on) and with the RCA cables unplugged. I got the amp refurbished, and although I have never had any problems out of refurbished products before, I think something inside the amp is shorting out.

Anybody have any other thoughts?

I realize grounding is probably the first thought. I have the amp under the rear seat, with the ground 6-8" away to a large seat hinge bolt. Also since it sounded fine for several months, it makes me think the amp is damaged.

Any thoughts are appreciated. Thanks.

stadt11 · December 17, 2008

How do you have your wires for the amp turn-on, power, & RCA cables? Your RCA cables should be routed on the opposite side as the power & turn-on.

Check your ground, make sure it's on bare-metal.

Also check loose connections on the amp itself.

Check your gains on the amp too, maybe they're too high.

DofD · December 17, 2008

It could be that the amp has developed an internal grounding issue. Since it sounded find for a few months and then started it's probably the amp. You could try cleaning your grounding point to make sure that no oxidation has built up and is causing the problem.

Have you made any other electrical mods recently that may have affected the grounding properties of the truck?

DofD · December 17, 2008

I'd also try hooking up a different speaker just to make sure that the source originated in the amp.

defragme · December 21, 2008

Thanks for the responses guys. Want to explore any other options before having to spend money on something new.

I know that rca's should be routed away from the power cable, but i just ran everything down the drivers side channel on this truck. Dont remember why I did that but for some reason it was going to be a pain to run the rca's to the other side. This shouldnt be a problem though, since it has been routed that way from the beginning without any problems at first. Also I still get the static with the rca's unplugged.

I did recently consider the possiblity that it could also be the sub, and I will try another set of subs I have laying around to see if that is it. I was leaning toward the amp since it was refurbished, and the sub was brand new.

The bad part about trying a different sub is that the static is not constant. I may get in my truck and start it, with the static coming on immediately and not going away for the entire trip. Or it may stop after driving a little while, or not start doing it at all.