

Extending the low frequency experience
The B21 subwoofer will elevate your audio experience by adding a detailed reproduction of the lower lows!
The brand new custom developed and built 21 inch driver, paired with our advanced port design, tuned down to 30 Hz delivers lowest frequencies in an maximum precision by minimal distortion. Whether you're enhancing the depth of electronic music or to live performances, the B21 ensures powerful and controlled low-end performance every time.
Stack´n´play
The B21 seamlessly integrates into setups with our renowned B30 and T24N, part of the legendary PA-SYS-ONE, featuring a consistent mechanical design: The B21 features stacking recesses on both the long and short sides for B30 subwoofers and the T24N placed on top. With a 80cm (31.5") depth and 70cm (27.6") height, it’s built to perfectly stack, giving users flexibility in vertical or horizontal configuration while maintaining sonic impact.
But there is much more to do for the B21
Besides the “extended low frequency” preset, we created a dedicated “full” preset which allows the use of the B21 directly with tops like the T24N or M15. This preset is designed to deliver the bass impact of an typical 18 inch sub but with the extended frequency range that only a 21 inch driver can provide. Two pole mounts for vertical and horizontal application beside using the existing QDB30 Quad Dolly completes the picture of flexibility.
And there are even more possibilities
The B21 is absolutely perfect for cardio applications. Directional B21 clusters provide a wide-band cancellation at the back with more than 17 dB SPL reduction in vertical or horizontal configurations of three units. In mixed subarrays for example with S32 or S33 cardioid subwoofers and B30/B18 cardio clusters, the B21 adds significant extended lows while still being punchy.
This makes the B21 the perfect solution for the high demands of today's listening habits in the live music and dance sectors. The superior design, flexible integration and precise low-end performance guarantee deep, immersive bass that captivates every audience, from small venues to larger stages meeting various applications.
Presets are available for:
Key Facts:
Drivers | 1 × 21" |
Frequency range | 27 - 125 Hz |
Power capacity program / peak | 3600 / 7200 W |
Impedance | 8 Ω |
Sensitivity 1 W / 1 m | 98 dB |
SPLmax / 1 m | 137 dB |
Connection | NL4 2± |
Dimensions (H × B × T) | 706 × 606 × 800 mm [27.8 × 23.86 × 31.5 in] |
Weight | 54.5 kg [120 lbs] |
Finish | Warnex texture paint |
Accessories | QDB30, FDB21, CoverB21, Cover2B21 |
Options | RAL colors |
Drivers | 1 × 21" |
Frequency range | 27 - 125 Hz |
Power capacity program / peak | 3600 / 7200 W |
Impedance | 8 Ω |
Sensitivity 1 W / 1 m | 98 dB |
SPLmax / 1 m | 137 dB |
Connection | NL4 2± |
Dimensions (H × B × T) | 706 × 606 × 800 mm [27.8 × 23.86 × 31.5 in] |
Weight | 54.5 kg [120 lbs] |
Finish | Warnex texture paint |
Accessories | QDB30, FDB21, CoverB21, Cover2B21 |
Options | RAL colors |
Karl-Hofer Str. 42, 14163 Berlin / Germany Industrial premises: Osterholzallee 140-2 71636 Ludwigsburg (D) phone + 49 7141 488 989 0 fax + 49 7141 488 989 99