High-powered dual 18-inch Passive Subwoofer for Dynamic Bass Reinforcement The GL218S Subwoofer is engineered for powerful, distortion-free bass output, even during high dynamic range performances. Equipped with two 18-inch drivers featuring 100mm voice coils and paper cones, this subwoofer delivers efficient and dynamic sound across long distances. The robust cabinet, constructed from 18mm birch plywood and finished with durable black textured paint, ensures longevity and easy transport with four large handles.