Ported enclosure for 2×12″ subwoofer Net volume: 108 liters. Tuning frequency: 35 Hz Diameter of speaker hole: 280mm Measurements cm: ( W x H x D ): 927 x 406 x 508. Note! The enclosure is designed for subwoofers with a sheet metal frame, and the mounting hole for the element is therefore 280mm. DD Audio′s cast-frame subwoofers are not suitable for this enclosure. Note! The enclosure comes with only 4 pre-installed protective grille screws. (required amount 14 pcs)