JBL SRX818SP/230 is a Self powered 18”, subwoofer system ideal solution for musicians. Maximum SPL (1m): 135 dB Frequency Range(-10dB): 29 Hz – 150 Hz Power Rating: 1000 W Peak LF Driver: 1 x 18 in Differential Drive Dimensions(H x W x D): 683mm x 684mm x 575mm (26.89in x 26.92in x 22.62in)