Buzzing sound from audio system

[lexfly]

hey guys, my names Thai and i drive a twin turbo soarer. i've got a pioneer dvd system with 2 12inch subs and 2 jl amps and kenwood speakers. for the past few months my sound system's been giving a buzzing sound, and when i accelerate it gets louder. but when the engines off but the cars still on, the buzzing sounds goes away. i've had my system checked by heaps of people and no -one can tell me wats wrong. can anyone help me, i'm really stressed coz the only thing i can do to get rid of most of the sound is turn my amp down very low. but that gives crappy sound coz u can hear and feel mainly the subs. wat do i do????

[InstallGarage]

Hello Thai,
Did you recently add any equipment? Did you try to clean the area where your ground wires contact the body of you car?