The WS218X is a high performance sub-bass system designed for use with large scale Wavefront and Blackline systems, in both touring and install applications. It features twin, 1000 watt 18" (460mm) drive units with magnet structure and suspension engineered for maximum linear excursion. The birch ply cabinet is fitted with six pocket handles and four 4" (100mm) castors for easy deployment. It features large area porting to reduce air noise. WS218X subwoofers are designed to be powered by Martin Audio MA4.2s power amplifiers.