The SR-C15B Sub-woofer system is designed to be used in conjunction with the SR-C8L or SR-C8S Line Array Speaker. TOA Type C speakers are module-type 2-Way line array speaker systems featuring a 20cm (8") low-frequency Neodymium woofer and two 2.5cm (1") Neodymium drivers. They are designed to take advantage of original TOA phase wave front control technology, enabling creation of a sound field combining clear audio reproduction and uniform sound dispersion.