Hello,

I just replaced my factory battery with a optima yellow top. I used the same battery ground but I am getting a ridiculous humming from my subs now. I have tried regrounding the battery and the amp but I have the same issue. If it matters its a MA Audio Hk602sx amp and 2 Mtx 9500 12's. I was wondering if I regrounded the head unit if that would maybe fix it? If anybody has any suggestions I would appreciate it!!

 

slowly rev your engine and tell me if it hums with the rpms. if so, you have engine noise. do the Big Three and it'll go away.

 

Well, Ive done the big 3 and it still does it. Even when the car isnt running and I turn everything on it does this. So im not sure what to check. But when I rev my engine there is no difference so I guess that eliminates the engine noise.

 

check all your grounds. is it a high pitched hum?

 

Well its more of a low rumble. I have tried a different amp and it does the same thing. As far as the grounds go I regrounded both the amp and the battery. I'm using all zero gauge wiring for my grounds and power. My rcas are ran on opposite sides of the car too. I also have a 5 farad power cap and when I unhook that it doesn't change.

 

Try re grounding your HU to the amp, run a 16 guage wire from the ground on the HU to the ground on the amp.
You could also have an issue with the RCA's, try new ones if the HU ground does not work

 

not to thread jack but whats "the big three"? I dont know anything about audio besides basic set up, with some electronics understanding.

 

pioneer radio by chance?

 

Its upgrading the major power and ground wires that are in the car.
Battery Ground, Alt to battery power, Alt ground. Thats how alot of cars do it however with the battery in the trunk the cobalts are a bit different, but same basic concept