For bass lovers, the subwoofer can never be too big. And for SW subs, we want to make sure our customers invest every penny in performance, and nothing else. A 15-inch sub is a common size for big rooms. We optimized our 15-inch driver for high efficiency.. We don’t like slow, muddy sound at all so we designed a fast-response coil. With all of these elements, we have a fast and powerful, competitively-priced 15-inch subwoofer.