Check the listing for details. Custom Ported Sub Box Enclosure for 2 8" Alpine Type R Series Subs ~ ACRYLIC ~. Condition: New. Listed at 339.95 USD. This listing is for a custom ported enclosure for 2 8" Alpine R-Series subwoofers. We use a 4" aeroport to reduce port noise so you get nothing but clean clear bass from your subs. Also, the subs are recessed 3/4" into the box. All the joints are glued and screwed together to ensure that the box will hold up against the high output of the subwoofer for as long as you need it to. Enclosure Details: - 3/4" MDF Construction - Plexiglass - 1/2" thick - 20" x 6" - Port Tube - 4" x 12" aeroport - Cutout Diameter - 7.25" - Black automotive carpet (Charcoal or light grey carpet may be substituted upon request) - Tuned to 35 Hz (adjustable by request) - Exterior Dimensions - 36"(wide) x 15"(deep) x 10.25"(tall) - Net Volume - 1.75 Cubic ft - Roughly 40 lbs - 2 Terminals included - Sealed air tight with liquid nails caulk