AC115S Is a high power Subwoofer system comprised of one 385mm (15") low frequency driver in a vented, front-loaded configuration for extended bandwidth. The rectangular cabinet is fitted with M10 threaded suspension points for ultimate flexibility. As a part of JBL's AE Application Engineered Series, a versatile family of Loudspeakers for a wide variety of fixed installation applications, AC115S provides a natural low-frequency sound quality.