The 21 inch Dual Subwoofer with its matched pair of Neodymium woofers is our most powerful subwoofer as it delivers 4000w RMS and a minimum 139dB SPL.
The robust 21 inch Dual Subwoofer enclosure is constructed from premium multi-laminate Birch plywood and is finished in 3 coatings of Jet Black impact resistant textured polyurea paint. Two NL4 connection panels are provided on the rear for input and linking. Each 21 inch Dual Subwoofer driver has its own connection plate. This gives you the option to link them if your amplifier will tolerate a 2-ohm load but we recommend you drive each cabinet with a 2 channel amplifier capable of delivering over 2000 watts into 4 ohms. The front of the loudspeaker is protected by a rigid steel grille.
You can learn more about Bishopsound by watching my videos on my Youtube channel I am adding more Video every month https://bishopsound.com/videos/
|Model||Beta BB221s (Textured Black Polyurea Paint)|
|Finish||A durable hard wearing protective waterproof coating. Its primary uses are automotive linings, industrial and military coating markets due to the superior finish and the very high abrasion resistance|
|System Type||21″ (Subwoofer) x 2|
|Frequency Range||29~1000 Hz|
|Impedance||4 OHM for each driver|
|Power RMS (W)||4000w|
|Max SPL (dB)||139dB|
|Connection||4 pole connector|
|Cabinet size||70*65*122 cm|
|Cabinet material||18mm plywood|
|Carton size||73.5*70.5*128 cm|
The Driver for our Dual 21-inch passive subwoofer is made by us at Bishopsound and here are the details:
|GENERAL CHARACTERISTICS ELECTRICAL CHARACTERISTICS|
|NOMINAL OVERALL DIAMETER|
|Nominal Voice Coil Diameter||312 mm Nominal Impedance 4 Ω|
|Magnet Weight||NEO Rated Power 2000 W|
|Flux Density||1.1 T Sensitivity@1W/1m 96 d B|
|Voice Coil DC Resistance||Re 3.6 Ω|
|Resonance Frequency||Fs 35.0 Hz|
|Mechanical Q Factor||Qms 10.5|
|Electrical Q Factor||Qes 0.45|
|Total Q Factor||Qts 0.43|
|Mechanical Moving Mass||Mms 335 g|
|Mechanical Compliance Cms||252 um/N|
|Force Factor||BL 24.3 Wb/m|
|Equivalent Acoustic Volume||Vas 260.0 It.|
|Maximum Linear Displacement||Xmax ±14 mm|
|Reference Efficiency||ηo 2.250 %|
|Diaphragm Area||Sd 1680 Cm2|
|Losses Electrical Resistance||Res Ω|
|Voice Coil Inductance@ 1K Hz LE m H||Hz LE m H|
|Voice Coil Winding||Copper|
|Voice Coil Former Glass Fibre||Glass Fibre|
I am very proud of my 21-inch Dual subwoofer.
Bishopsound Speakers and associated products are competitively priced, high-quality and are focused on delivering a superb British tone.
Every customer order is managed and handled by me as I must ensure a fast and efficient service. I aim to treat customers as I expect to be treated myself and always give of my best.
Bishopsound design and manufacture in the United Kingdom, China, and India. My goal is to provide my customers with high quality, sensibly priced Professional Audio.
Andrew made his first speaker in 1972 and has many years of experience creating and delivering speakers systems. Backed up by my standard 30 Day Money Back Guarantee.