I saw a post on some other site that was really cool for OB speakers. In order to experiment with different drivers, this guy cut a large hole in a baffle, and then made several disc's that would fit into that hole, bayonet style, so it was quick and easy. Each disc has a hole cutout for different size drivers. So, if you wanted to try an 8" driver, use the disc with the 8" cutout and then take that disc, and insert it into the bayonetted hole in the baffle.