Ground Zero Vented SPL subwoofer loaded enclosure. Please note: This is a listing for ONE subwoofer loaded enclosure. Passive vented enclosure including 6.5? Vented SPL subwoofer loaded enclosure. 16.5 cm / 6.50. 8.5 L / 0.30 cu. Dimensions (W x L x H). 410 x 280 x 130 mm / 16.14″ x 11.02″ x 5.12.