So I recently acquired a bose acoustimass 7 subwoofer for pretty much free, but I cannot get it to work for the life of me. It will not work as a subwoofer, I haven't tested if the cube speakers work via input on this or not yet. Is there an easy fix to this? I'm currently attempting(failing) at disassembling the back of the subwoofer because I cannot seem to get it off (the back cover)