SE-Audiotechnik – B 21 – 21″ Passive bassreflex subwoofer


B-21 is a multi-purpose passive bassreflex subwoofer with high power SE AUDIOTECHNIK 21″ woofer.

Extremely flat frequency response extends down to 25 Hz.

Smart design ensures easy handling and operation in various applications, including cardioid subwoofer stacks.

SKU: B 21 Categories: ,


Port design
Aerodynamic port design reduces distortion and airflow noise. The unique asymmetric shape reduces port noise drastically by (-35 dB).

Sockets at front grill
Convenient multiple Neutrik speakON® sockets in front and back allows for easy set up ideal for live performances.

Octopus feet
The so called “octopus feet” are made from some flexible rubber/plastic material, which provides good slip resistance.

Cardioid subwoofer setups
Due to the intelligent stacking design and the front and rear sockets, it is possible to operate our B-Line subwoofers as a cardioid setup without any problems.

Additional information



Frequency Range (-3 dB)* 34 Hz – 130 Hz
Frequency Range (-10 dB)* 26 Hz – 160 Hz
Coverage (-6dB) [H x V] Omnidirectional
Nominal Impedance 8 Ω
Sensitivity** 99 dB
Peak Power 4000 W
Continuous Power*** 1000 W
Maximum Peak SPL**** 142 dB
System Type 1-Way Passive System
Transducers 1 x 21″ Driver
Enclosure Vented Box
Connectors Input Signal: 2 x Neutrik SpeakON® NL4
Link Input: 2 x Neutrik SpeakON® NL4
Link Output: 1 x Neutrik SpeakON® NL4
Wiring Pins 1+/1- : Driver
Pins 2+/2- : Link (Output CH 2, Pins 1+/1-)


Product Dimensions [H x W x D] (Including Rigging) 666 x 585 x 832 mm
Net Weight 51 kg
Packaging dimensions [H x W x D] 796 x 685 x 930 mm
Total Weight 61.5 kg
Cabinet 15 – 24 mm Plywood
Cabinet Finishing Black or White Polyurea Coating
Grille Powder Coated Perforated Steel
Hardware 4 SE Audiotechnik® Ergonomic Handles
8 Rubber Feet and Top Slots
M20 Pole Thread


Pole Bar SPS20
Flight Case B21 FC
Transport Dolly B21 TD
Transport Cover B21 TC


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