I bet your box is coming apart.....seriously. That hammer and chisel noise you speak of is probably the wood banging together. Throw some more screws in that thing!
Well Found the problem, The Box itself isnt coming apart but the one of the 2x2's bracing the thing was. So Cut a new one and Glued/drilled it and should put the subs back in the car tomorow.
Thanks for all the help everyone.... One more thing do I use just any screws because my experiences with screws and MDF = lots of problems should i predrill the hole first?? and special MDF screwws?