PreSonus AIR15S Active 15-Inch SubwooferDesigned to complement any full range PA loudspeaker and a perfect companion for the PreSonus AIR10, AIR12, and AIR15, the AIR15s subwoofer delivers a powerful, clear, and accurate low end punch. With its 15 inch low frequency transducer, driven by 1,200 watts (dynamic) of Class D power, it provides plenty of detailed bottom end all the way down to 35 Hz. Yet it is portable and well suited for mobile applications, as well as installed systems.