Hissing noise from speakers

[ShadeTreeMechanic]

I have seen amps do that with the gain turned up. If it goes away when gain turned down then the solution is to run a stronger signal to the amp with the gain down. If it still does it with the gain down and RCA's unplugged, then there might be something wrong with the amp.

[Skullz]

Since it does it with the engine off, you now need to isolate which piece is the cause of the noise as it is defective and needs repair or replace.

Use your phone connected in place of your h/u to the first piece in the chain of gear and work your way back trying to find the source of noise.

The point here is a process of elimination till you find the problem and take corrective action.

You always want to start at one or the other unless you know what piece it is.

EDIT: Do you have anything using stock wiring?

[CarbonCone]

Nothing is connected to the headunit atm,

Amp only has battery, remote from fusebox, ground and tweeter speaker cable connect and gets the hissing sound. so headunit is out of the picture

All 3 of my amps make the noise seems very odd, going to run straight wires from the battery to amp and see how it goes. maybe the quick connection plugs aren't all that good.

[CarbonCone]

So installed amp under the hood, Only had battery and ground connected, had remote coming off battery also and still had the hissing noise, I checked and cleaned the battery ground so this isn't the problem. would a bad chassis ground/alterntor cause this problem?

I'm totally stumped by this.

[Skullz]

Bench test this stuff to remove any doubt it is the equipment making the noise.

Just because you tried 3 things doesn't mean they aren't bad, while i'm not saying that they are, you have to test them.

Once you know everything works outside the car, you need to go through every single wire to make sure something isn't pinched or cut contacting the body some place causing the issue.

The most important thing to do is to eliminate one thing at a time, which is why trouble shooting takes time and patience.

Get a battery and start benching your gear out side of the vehicle to remove any doubt about it being the cause, once you eliminate the gear then move on to the wiring.

Most times it can be traced to speaker wires inside of doors or going from the amp to the speakers, disconnect one speaker at a time and see if the noise stops.

[Skullz]

Trying a hodge podge of shit doesn't mean you have tried everything, this is a process of elimination, and it is best to start at one end and work you way to the other so as not to miss anything, to not check or test everything can mean never finding it.