The Electro-Voice SB122PI 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 full face weatherized stainless steel grill with hydrophobic cloth inhibits water from entering the port or coming into contact with the woofer. The SB122PI 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.
SB122-WEATHER RESISTANT SPEAKER, The Bosch Group ADI, Electro-Voice