Jus owned M3300SF.... nice~!!!

Hey guys... just want to know. Why my subwoofer will produce a humming sound usually when watching movie. If it is in music.. it is hardly to identify. The humming sound will increase when volume is increase too... I try to unplug everything and connect back again... Btw.. my speaker is Edifier M3300SF.. Hope u guys can help me... I just wondering will it be sth like the earth loop problem??? Dis is too hard for me.. LOL.. As i'm jus a layman T_T and the humming sound is irritating.

Erm.. if only the cable is plug into my speaker only wifout connect to the computer.. its seems ok.. But when it is plug into the computer... den the humming will come back even nth is open (no music or movie).

If i were needed to connect directly to the power outlet wifout going through the extension. Then my computer cant on... LOL.. Cause i need the extension together to on both computer n speaker.. So.. does this test can run wifout my computer on too?