System Hiss With A Few Follow Up Questions.

[Skullz]

Could have a bad spark plug or plug wire causing the interference.

Could have bad or broken grounds on the engine to the battery/chassis, big 3 usually takes care of those.

Check every ground you have, including on tugging hard on wires with lugs on them to make sure they are not semi loose causing an issue.

Disconnect all speakers and try each one, one at a time hooked up playing to see if you have a pinched or cut wire somewhere.

This is one of those things where it is a process of elimination, and try to start at one end and work your way back

[G-Difficult]

have you taken the amp out of the car and bench tested it yet? Or at least tested it inside the car without using the wiring that is in the car right now? If not get a pair of speakers and wire them directly to the amp and see if the sound is still there. No RCA input hooked up, just power and speaker wires/speakers.

That's a good idea. I actually knew about that test but forgot about it. Ill try it tomorrow after work with a spare speaker. I already have a chord that I can use to plug directly into my amp. Thanks

[fordpride]

Had the same issue. Mine turned out to be the factory ground to the head unit. I ran a new ground to the firewall and problem solved.

[ShadeTreeMechanic]

The hiss that you hear is like static or "air"? With the engine off and rcas unplugged from the amp? Does it go away with the gain turned all the way down? If your source doesn't put out a lot of voltage, it will cause the gain to be adjusted high to compensate for the low signal. The solution is to turn the gain down and use either a source with higher output or use a pre amp to drive the line. Some EQs have a pre amp built in.

[MrSkippyJ]

He said he's tried it with the RCAs unplugged and the gain turned down. Nothing about the engine being on or off though.

[ShadeTreeMechanic]

With the gain lower the hiss was less. I mean turn it all the way down to see if it goes away.

[G-Difficult]

Just wanted everyone to know that I took it to a shop and they are pretty sure it's the amp. They told me in order for the ground to be with problem, the static would need to only be there when there is signal

[MrSkippyJ]

With the gain lower the hiss was less. I mean turn it all the way down to see if it goes away.

I actually missed where he said it was less, my bad!