Electro-Voice ETX-15SP 15" 1800 Watt Powered Subwoofer A powered subwoofer that can be used in a variety of portable and permanent applications Single-knob DSP includes presets for multiple configurations and top+sub combinations (performance style, locations, and space) Designed to optimize transducer linearity and advanced limiter algorithms for independent peak and thermal transducer protection True cardioid DSP preset delivers true cardioid response across all frequencies The enclosure is constructed out of 18-mm, 13-ply birch plywood finished with EVCoat Includes professional castors and combination pole mount receptacle for use with two-way speaker models Loudspeaker system performance is optimized via an LCD screen, and the front LED can indicate power or limit