The Stereostone / Sunfire Sub Rock incorporates the 2700 watt sunfire true sub woofer MK II in a weather proof custom Riverrock Soundstealth™ enclosure. This product offers incredible deep bass sound reproduction outdoors, hidden totally from the listeners eyes. 2700 Watt built in amplifier frequency response 16 hz - 100 hz +0, -3 db. Both high and low level stereo inputs, input level control crossover points variable from 35 hz to 100 hz. Available 110v or 220v with isolation transformer built in.