Sound system problem?

i have a problem with my sound system, and i don'y know what it is. when im listining to music my sound system is ok , but as soon as i turn off my sound system or the radio , i get a big bass sound like brrrrrrrrrrr untill i turn the radio back on . so for now i just keep my radio on untill i can fix it. does anyone know what this problem is?
thank you

well, tell us what your sound system consists of, so we can narrow the problem down.

it's called "noise"

- make sure your wiring is tight enough and that you don't have 2 wires getting in contact with each other.
- make sure your ground cable is solid, also how do you ground ?
and of couse you'll do all this with the negative battery terminal removed right ?