Recessed Side Panels increase structural integrity, eliminates unwanted flex and vibration.Specially Formulated Aliphatic Wood Glue to ensure an airtight seal between all MDF parts with a second application of glue around all internal joints after final assembly.Pneumatic Applied Brad Nails to pull tight and hold the MDF parts during the glue drying process and help assure a no-leak, no-rattle air chamber.Premium OEM Grade Carpeting for factory look and durability.Enclosure Dimensions Sub cut out: 7, mounting depth: 5.12., Height: 9, Width: 20, Depth: 5.12