B&C 21DS115 21" Professional Subwoofer Driver

Regular price $1,383.69 See Price in Cart


  • 3,400 Watts continuous program power capacity (RMS)
  • 116 mm (4.5-inch) split winding copper voice coil
  • 60 mm peak-to-peak excursion before damage
  • 15.6 mm xmax @ 1/3 gap; 20.3 mm usable excursion @ 2/3 gap
  • Neodymium magnet allows a very high force factor and linear excursion
  • Double silicone spider with optimized compliance
  • Ventilated voice coil gap for reduced power compression
  • Aluminium demodulating ring for very low distortion
  • 21” Nominal Diameter
  • 99 dB sensitivity
  • 32.6 lbs.
  • Available in 4 Ohm and 8 Ohm options (Please be sure to order the correct one; send us a note if you have any questions.)

Manufacturer's Datasheet 4-Ohm (PDF)

Manufacturer's Datasheet 8-Ohm (PDF)


This super-premium driver from the professional audio world works very well in the MBM-21 cabinet. Two drivers produce upwards of 133dB from 30Hz up and upwards of 135dB at 70Hz.  If you are looking for a clean, impactful, music bass driver, this is an excellent choice.

The driver's high efficiency and high resonant frequency allow it to achieve this enormous output with only about 10% as much real power at 70Hz as the UM-18 (one of our favorite home theater drivers).  The result is less power compression, less distortion, and a much 'punchier' mid-bass. 

Two channel enthusiasts looking for a subwoofer will find the 21DS115 produces exceptionally linear bass.  Good inductance control keeps distortion to a minimum allowing each note of the music to be represented with accuracy and definition.  

The 21DS115 has slightly more excursion capability than the 21SW152.  For most folks, we recommend the 21DS115.  For those who will be running their subwoofers up past 100Hz, the 21SW152 offers a smoother upper end response.

The 21DS115 is not the lowest cost driver, but it does provide benefits that in the right application make it more than worth the price, which is why we are proud to offer it to you.