B-Line 21" - The Powerhouse

The mighty 21" driver with its huge 5" voice coil thunders with up to 142 dB max. SPL down to the deepest depths – performing from 25 Hz it is the bass beast in our line-up.

With a load capacity of up to 4,000 W peak, it delivers enough power for every stage and every event. Despite its higher weight, it is easy to manoeuvre thanks to the two wellpositioned recessed grips on both sides.

In direct comparison, as expected, it delivers the most robust performance at the low end and generates more than enough pressure in any situation.

The active versions of this bass monster have a 1,600 W Class-D amp on board.

The great advantage of active speakers is the amplifier that is already built in. So there is no need for an external device - the internal amp is optimally matched to our speakers! The B 21A is powered by a mighty 1,600 watt (peak) amplifier. Integrated DSP presets allow you to load carefully preset system setups that are optimally matched to SE AUDIOTECHNIK® products.

This way, the entire system is quickly and easily set up and perfectly adjusted. The large display and the push/turn control can be used to switch from normal operation to an end-fire or cardioid configuration in a flash.

Parameters such as EQ, delay, sensitivity and phase can be adjusted and saved in custom user presets.

B 21A

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Products of the B-Line 21'' - Series

B 21

B 21

B 21A

B 21A


B-Line 21" 6
B 21
B 21A
Frequency range (-3 dB) *: 33 Hz - 130 Hz 33 Hz - 230 Hz
Frequency range (-10 dB) *: 26 Hz - 160 Hz 27 Hz - 280 Hz
Coverage angles (-6dB) [H x V]: Omnidirectional Omnidirectional
Nominal Impedance: 8 Ω 8 Ω
Sensitivity **: 99 dB
Peak Power: 4000 W 1600 W
Continuous Power ****: 1000 W
Maximum Peak SPL *****: 142 dB 139 dB
System type: 1-way passive system 1-way passive system
Transducers: 1 x 21" driver 1 x 21" driver
Enclosure: Vented box Vented box
Connectors: Input / Link signal: 4 Neutrik speakON® NL4
Link output: 1 Neutrik speakON® NL4
Input signal: balanced XLR 3-pin female
Link output: balanced XLR 3-pin male
Power input: powerCON® 20A
Power link output: powerCON® 20A
Wiring: Pins 1+/1- : driver
Pins 2+/2- : link (Output CH 2, pins 1+/1-)
Pin N: Neutral
Pin L: Conductor
Pin E: Ground
Product dimensions [H x W x D] (Including rigging): 666 x 585 x 832 mm 666 x 585 x 832 mm
Net weight: 51 kg 55 kg
Packaging dimensions [H x W x D]: 796 x 685 x 930 mm 796 x 685 x 930 mm
Total weight: 61.5 kg 65 kg
Cabinet: 15 - 24 mm plywood 15 - 24 mm plywood
Cabinet finishing: Black or white polyurea coating Black or white polyurea coating
Grille: Powder-coated perforated steel Powder-coated perforated steel
Hardware: 4 SE Audiotechnik® ergonomic handles
8 rubber feet and top recesses for stacking
M20 pole thread
4 SE Audiotechnik® ergonomic handles
8 rubber feet and top recesses for stacking
M20 pole thread
Pole bar: SPS20 SPS20
Transport dolly: B21 TD B21 TD
Transport cover: B21 TC B21 TC
Amplifier rain cover: - P801DL RC
All product specifications are subject to change without prior notice. * Measured with a 6th-order Butterworth low-pass filter applied
at 130 Hz
** Half space, 1W / 1m, on axis
*** According to EIA-426B Standard (based on RMS Voltage
**** Max Peak SPL = Sensitivity + 10log10(Continuous Power) + 12 dB Crest Factor



M20 Pole Support to pole mount an M-F3A or M-F3A PRO on any B-Line subwoofer

B 21TD

B21 TD
Dolly board for B 21 subwoofer