Hi. I just got a used Acura 2002 RSX and it came with an after market boom box. I noticed that when driving and the radio is off there is a sound coming from the box like a "grounded" sound and its noise/sound starts from soft to becoming loud as if the box will explode but when I turn on the radio the box will sound normal. It sounded like, "hhhmmmmmmmmmmmmMMMMMMMMMM !!!!!" What could be wrong? Thanks.