Rockville RDVB12 Dual 12" 1.75 cu.ft. MDF Vented/Ported Subwoofer Enclosure Box Rockville RDVB12 Dual 12" 1.75 cu.ft. MDF Vented/Ported Subwoofer Enclosure Box Dual 12" vented subwoofer enclosure. Hardwood MDF, Machine precision cut mounting holes 3/4" USA Heavy Duty MDF Construction. Top of the line Glue for extra durable adhesion High quality GOLD spring loaded terminals. Made in the USA. Tuning Frequency: 41 Designed, tested, and engineered to work with most of todays popular woofers. These enclosures are built with the quality additives needed to maximize the performance of any sound system. Rockville RQB12 QBOMB Single 12&#034; Vented Subwoofer Enclosure With Rhino Bedliner Finish Proudly Made In The USA, Using Only The Finest Quality Materials - For The Best Level of Performance From Your Subs! 3/4&#034; USA Heavy Duty MDF Construction Machine precision cut mounting holes Top of the line Glue for extra durable adhesion Designed, tested, and engineered to work with most of todays popular woofers. These enclosures are built with the quality additives needed to maximize the performance of any sound system. Tuning frequency: 43Hz Type of Enclosure: Vented Enclosure Sub Size: Single 12&#034; Dimensions in Inches: 15&#034; L x 22&#034; W x 13.5 H&#034; Top and Bottom Depth: 15&#034; Mounting Depth: up to 8.75&#034; (enough depth for any sub on the market) Gross Volume Per Sub (Measurement for the outer dimensions of the box): 2.5 Cubic Feet Net Volume Per Sub (Measurement for the outer dimensions of the box less the thickness of the wood): 1.8 Cubic Feet