2 X B&C 21SW152-4 21" ported build, 15cu.ft per | AVS Forum
B&C 21SW152-8 21" Neodymium Subwoofer 8-Ohm DJ Live Sound 4000W Bass Sub.
B&C 21SW152 is a very high power 21" subwoofer for speaker subwoofer systems- B&C 21SW152 21" Subwoofer has a lightweight neodymium magnet - B&C 21SW152 21" high power speaker for speaker subwoofer