The Electro-Voice Sb122 bass module is a very compact, lightweight subwoofer system that is designed to add bass enhancement to EV Sx and Zx Series speaker systems. The Sb122 combines the advantages of a long-throw 12" woofer with a strong, lightweight composite enclosure. The large vent provides less vent compression and turbulence for increased low frequency output. The EVS12SB cast frame transducer created for the Sb122 uses the same motor and suspension design as the EVS18S used in EV’s larger systems. With nearly two inches of peak-to-peak excursion capability, this is literally a twelve inch with the heart of an eighteen. An integral low-pass filter allows the Sb122 to be directly connected in parallel with a full-range speaker for truly impressive low-end output without the need for an additional amplifier and processor. The filter is transparent below 160Hz, allowing the Sb122 to be used as an independent subwoofer in biamp applications without the need to disable the internal filter. For maximum output in biamp applications and protection of the full-range system when running in parallel, a 40Hz Hi-pass (subsonic) filter is recommended. The Sb122 features a convenient pole mount socket on top of the enclosure to allow a small full-range speaker such as the Zx1 or Sx80 to be mounted on the optional ASP-1 accessory pole, resulting in a compact system than sounds much bigger than it looks.