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SD-21EL

The SD-21EL is an ultra high output low frequency transducer. The 21 inch (533mm) diameter piston will produce extremely high sound pressure evels at very low frequencies and is ideal for high level deep bass and sub woofer response in both live sound and recorded music venues. The combination of a large radiating area and high linear displacement will generate substantial acoustic power. The operating range is 20Hz to 200Hz. The transducer uses high energy neodymium magnetics to achieve a very high acoustic output to weight ratio.

The SD-21EL employs an extremely large 6 inch (152mm) diameter voice coil that provides an AES rated 2000 watts of continuous power handling and a full 8000 watts of peak rated power handling when sufficient amplifier headroom is available. It is recommended that the transducer be loaded into a properly designed vented enclosure. The SD-21EL utilizes Dynatech's Auto Balanced Cooling (ABC) technology to not only improve transducer power handling and reliability but to also increase power compression performance by carefully balancing and directing airflow to critical areas.

The voice coil design is an “inside/outside” geometry with Dynatech's square wire technology to improve conversion efficiency and provide a very large cross-sectional area for superior cooling.

System linearity is achieved by employing magnetic flux demodulation devices in the structure to increase fidelity and sonic accuracy. The system suspension has been designed specifically for high linear displacement and extended low frequency response. The double spider design insures very high displacement and linear response while maintaining excellent control. For additional mechanical power handling it is recommended that a high order high pass filter be used and tuned immediately below the enclosure tuning frequency. The cone has been treated with a conformal coating designed to provide additional mechanical damping and moisture resistance.

The transducer chassis is a die cast aluminum design that insures a very high degree of structural integrity.

Download Specification Sheet

GENERAL SPECIFICATIONS

  Nominal diameter   530 mm/21 in
  Power rating   2200 W(AES)
  Nominal impedance   8Ω
  Sensitivity   98 dB
  Frequency range   30-300 Hz
  Effective Piston Diameter   460 mm/18.1 in
  Voice coil diameter   127 mm/5 in
  Chassis type   Cast aluminum
  Magnet type   Ferrite
  Magnet weight   4.4 kg/152.3 oz
  Former material   Glass fiber
  Cone material   Pulp Paper
  Surround material   Cloth
  Packaging Quantity   1 Piece / Pack
  Packing dimension WxDxH (mm)   580 x 580 x 300
  Net weight   19.5 kg/42.99 lb
  Shipping weight   20 kg/44 lb

FEATURES

  • 6” Ultra Large Format Voice Coil
  • 8000 Watts Peak Power Handling
  • Active Balanced Cooling
  • Ferrite Magnetics
  • Double Spider Suspension

SMALL SIGNAL PARAMETERS

  Re   5.8Ω
  Fs   32.8 Hz
  Mms   315.02 g
  Qms   9.526
  Qes   0.378
  Qts   0.364
  Vas   292.92 lt
  BI   31.55 Tm
  Le (at 1kHz)   0.81 mH

SD-21EL

The SD-21EL is an ultra high output low frequency transducer. The 21 inch (533mm) diameter piston will produce extremely high sound pressure evels at very low frequencies and is ideal for high level deep bass and sub woofer response in both live sound and recorded music venues. The combination of a large radiating area and high linear displacement will generate substantial acoustic power. The operating range is 20Hz to 200Hz. The transducer uses high energy neodymium magnetics to achieve a very high acoustic output to weight ratio.

The SD-21EL employs an extremely large 6 inch (152mm) diameter voice coil that provides an AES rated 2000 watts of continuous power handling and a full 8000 watts of peak rated power handling when sufficient amplifier headroom is available. It is recommended that the transducer be loaded into a properly designed vented enclosure. The SD-21EL utilizes Dynatech’s Auto Balanced Cooling (ABC) technology to not only improve transducer power handling and reliability but to also increase power compression performance by carefully balancing and directing airflow to critical areas.

The voice coil design is an “inside/outside” geometry with Dynatech's square wire technology to improve conversion efficiency and provide a very large cross-sectional area for superior cooling.

System linearity is achieved by employing magnetic flux demodulation devices in the structure to increase fidelity and sonic accuracy. The system suspension has been designed specifically for high linear displacement and extended low frequency response. The double spider design insures very high displacement and linear response while maintaining excellent control. For additional mechanical power handling it is recommended that a high order high pass filter be used and tuned immediately below the enclosure tuning frequency. The cone has been treated with a conformal coating designed to provide additional mechanical damping and moisture resistance.

The transducer chassis is a die cast aluminum design that insures a very high degree of structural integrity.