When i sent my XXX 18 to RE for Repair i built a crate kinda like RE used to use it contained 2 pieces of OSB board 3/4 with 12 pieces of 2X4 screwed together with 3" screws and stapled for bracing then stuffed around the sub with pieces of 4" foam then cut 2 pieces of 4" foam to fit on top and bottom of crate packed so tight is was a pain in the *** to test fit... all in all it arived at RE with half the basket through the cone and part of the motor broke with 4 of the 12 pieces of 2x4 broke.......UPS FTW.... got $475 on insurance