The B2 subwoofer with its high output bandpass horn design and extremely high SPL is ideal for extended bass requirements. It is configurable to be either an infrabass for the C4 system or a high output, alternative subwoofer for the F1222 or C7 systems. When used with a C4 system, d&b recommend a ratio of four C4-SUBs to one B2. The B2 cabinet is constructed from marine plywood, has an impact resistant paint finish and eight integral steel handles. The front of the subwoofer cabinet is fitted with catches at the sides for securing an optional wooden lid, and mounted on the rear are four heavy duty wheels.