... driver, vented sub-bass system with 2x18" LF drivers. It is a line array subwoofer, pro speaker, speaker system. Subwoofer / ... long-excursion, 18" (460mm)/4" (100mm) voice coil drivers with water resistant cones and triple roll surrounds.TECHNICAL SPECIFICATIONS ... dual driver, vented sub bass system,Drivers: 2x18" (460mm) / 4" (100mm) voice coil LF drivers, Frequency response: 35Hz-150Hz±3dBRated ...