The Bose F1 Model 812 Flexible Array Loudspeaker is the first powered portable loudspeaker that lets you control its vertical coverage pattern. Simply push or pull the array into position to create “Straight,” “C,” “J” or “Reverse J” coverage patterns. And once set, the system automatically changes the EQ to maintain optimum tonal balance for each coverage pattern. So whether you’re playing at floor level, on a stage, or facing raked seats or bleachers, you can now adapt your PA to match the room. If you want extended bass response, simply add the Bose F1 Subwoofer (sold separately). It packs all the power of a larger bass box into a more compact design that’s easier to carry and fits in a car. A mounting stand for the loudspeaker is integrated right into the body of the subwoofer, so you always know where it is, making setup fast and easy. Frequency response (-3 dB) is 52 Hz .