BS Series | BS221  | BS318  | BS218  | BS215  | BS212  | BS112  | BS280 |
                  | BS250  | BS180  | BS150  | BS320  | BS210/BS286  | BS820  | 
BS221 is a subwoofer which uses 3 cavity bandpass design.loading 2 x21 "low frequency drive unit, each low frequency drive have independent cavity.Two paper cone work together in front of the third open cavity, which greatly improve the system efficiency,and effectively reduce the distortion.BS221 as other sound system of supplement, its low frequency response can be extend down to 30 Hz,as ultra low frequency array, it only could be stacked on the ground routinely.BS221 use multilayer birch plywood to make the enclosure, with elastic coating or environmental protection coating shell. The front panel use metal mesh enclosure stick acoustic soft sponge as the speaker's protection.Side plate combine 8 handles and wheel plate buckles,also dispose with 16 pulley mounting screw in rear panel. Terminal is disposed with NL4 parallel connection, and the switch botton for bi-amp or single-amp drive. When more than one BS221 stacked together, there are 4 rubber pads at the bottom of each speaker could be embedded to the groove of others, in order to aviod sliding.
■ 2 x21 "subwoofer system
■ three-cavity bandpass technology
■ enormous power, excellent transient response
■ extremely low distortion, ensuring ultra low frequency clarity
■ optional bi-amp or single-amp drive
■ optional wheel plate transportation
■ stackable
■ Large stadiums, arenas, all kinds of performances
■ Entertainment venues, nightclubs, bars
■ Theme park and concert hall
■ Mobile or fixed installation
■ As subwoofer of other audio system
Frequency Response
Nominal Impedance
Power Handing
Maximum SPL
Crossover Frequency
30 Hz - 70 Hz @(±3 dB)
106 dB SPL (1W @ 1m)
2x8 ohms /4 ohms
2x1200watts, 2x2400watts, 2x4800watts
139 dB
70 Hz
Low Frequency
2 x 21(in) 530 mm dia, 125mm(5in) voice coil dia
Enclosure Construction
Input Connectors
Dimensions H x W x D
Net Weight
25 mm birch plywood with structured
Wear-resistant textured black paint
Bi-amp or passive drive
NL4 x 2
620mm x 1400 mm x 945 mm
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