BP-SD21-S3 Sub Engine 21″



The BPSD21-S3 Sub Engine comes with the most powerful low frequency transducer we have ever found. It boasts folded-horn output from a box one -half the size of one of our WH folded horns. The 21” Neodymium woofer has a 6” voice coil that can handle 2500W RMS, 5000W Program and 10,000W Peak.  When it is used with a bridged 6000W amplifier, the low frequency output is staggering. The frequency response curve is 3db down at 32 Hz.

The tour version is available with handles and an attachable wheel-board.



System TypeDouble Tuned Band Pass
Active or PassiveFor Use with Active Processor
Program Power ( Watts )2500W RMS Continuous, 5000W Program, 10,000W Peak
Bi-ampable Yes
Nominal Impedance (Ohms)8 Ohms
Sensitivity (dB @ 1Watt/1m)104 Db one watt/ one meter
Max SPL (dB)142 dB
Frequency Response (Hz +/- 3dB)32-300Hz
Crossover Frequency (Hz)32-80Hz Recommended
Driver Configuration21″ Neodymium Woofer
LF Driver(s)Single 21″ Woofer with 6″ Voice Coil
LF Program Power ( Watts )2500W RMS Continuous, 5000W Program, 10,000W Peak
LF Impedance (Ohms)8
InputsDual NL4 Speakon Pins 1+/1-
Bar HandlesYes
Enclosure Materials3/4″ to 1.5″ Birch Plywood
Baffle Material3/4″ Birch Plywood
16 Ga. Perforated Steel
Finish / CoveringBlack Durablast Coating
Optional Finish / Coveringother colors available
Dimensions (DWH, inches)30 x 25.5 x 37 inches
Dimensions (DWH, cm)76 x 65 x 94 cm
Weight (lbs/kg)170 lbs / 77 kg