Check the listing for details. Custom Ported Sub Box Enclosure for 1 12" Massive Audio HIPPO XL Sub Plexiglass. Condition: New. Listed at 374.95 USD. This listing is for a custom enclosure for a 12" Massive Audio HIPPO XL sub with a plexiglass window. We use 3" aeroports to reduce port noise so you get nothing but clean clear bass from your sub. Also, the sub is recessed 3/4" into the box. We use an internal brace as well as a double top baffle. All joints are glued and screwed together to insure that the box will hold up against the high output of the subwoofer for as long as you need it to. - 3/4" MDF Construction - Window - 1/2" Plexiglass - 12" x 10" - Port Tubes - 3" x 11" - Tuned to 32 Hz (adjustable by request) - Black Carpet (charcoal carpet available by request - Exterior Dimensions - - 32" Length - 16.5" Height - 15" Depth - Volume - 3.0 Cubic Ft - Roughly 60 lbs - 1 Terminal included - Sealed air tight with liquid nails caulk