I pulled out of my drive way one morning cel phone rang then my stero went into high pitch sound. So I turned it off right away turned it back on everything was fine later that day I noticed a sound like the speaker grill was loose but it wasnt. So I took everything apart thinking it was the foam around the sub thats also fine its the sub itself. Im looking to see what other subs I can stick in there my self without adding amps or anything.