Your really 18? Hell your doing better than Grandmps on here. Who is still deciding on subs and making threads. Anywho, that sub position can be fixed. Just cut up an exact diameter of the mounting depth, grab some glue/caulking and smear that **** around the outside diameter of the piece and place 'er on top. Before that tho, get a few pieces of scrap wood and make them say 4" long by 2" wide and screw 1/2" of the length under the mounting depth cutout of the enclosure. Maybe the entire length of the hole, like 15" long or so prob wouldn't hurt. Anyway, just an idea for ya if you get bored one day and wanna try it out w/o spending a dime.