I had a 15" DVC I bought from PE make some weird banging noises also. Turned out that Eminence (who also make that particular driver for PE) add weight inside the dust cover to get the fs down in their subs, and this weigh seems to have a habit of coming loose once in a while since the guy at PE knew exactly what I was talking about when I called about it. Anyway they replacd it with no problem or cost to me. Actually sent out a new one before I sent back the old one! They do have good service so I wouldn't worry if the driver turns out to be pooched. Kelly