Descend Series DN15 15” Subwoofer. Monumentally. Uncompromised. Performance. Massive, uncompromised bass performance, from our most powerful subwoofer ever. Unique technologies add unprecedented clarity, power and seamless system integration. The DN15’s unique 3XR Architecture provides triple the bass-producing surface area of a traditional 15” ported subwoofer. This extra surface area moves more air, resulting in monumental low end. And because 3XR doesn’t use ports, it also provides crystal-clear sound with no port noise distortion.