3 XTR-15 EZ (9cf 33Hz)DIY BLUEPRINT FOR 3 ORION XTR-15 SUBWOOFERSVOLUME: 9cf netTUNING: 33HzPORT AREA: 50.27in^2(5.59in per cube)DIMENSIONSWidth: 45inHeight: 17-7/16inDepth: 26-3/4in$15.00PriceAdd to CartBuy Now