The Rockustics OneSub and DubSub subwoofers are built with a durable, rock enclosure designed to withstand rain, frost, snow, and ice. The OneSub is a stand-alone, passive sub that requires a sub amplifier with an active crossover while the DubSub functions as a Sub/Sat system. Simply wire two additional, full-range speakers to the DubSub and create a three speaker sub/sat system that can then be powered by any traditional amplifier with no need for a sub amp or external crossover. Applications:The OneSub & DubSub are ideal choices for any outdoor setting.