Select Category


Alternative/Current Model:


  • 97 dB SPL 1W / 1m average sensitivity
  • 100 mm (4 in) Interleaved Sandwich Voice coil (ISV)
  • 3000W program power handling
  • 60 mm (2,76 in) peak to peak excursion
  • Ultra linear dual magnet motor design
  • Single Demodulating Ring (SDR) for lower distortion
  • Composite reinforced straight ribbed cone
  • Optimized high grade neo magnet assembly
  • Recommended for subwoofer usage in high excursion vented enclosures

The 21NLW4100 is a 21" (533 mm) extended low frequency loudspeaker, designed for use in vented enclosures and infra subwoofers. The loudspeaker is designed to withstand high power levels without damage while providing clean and undistorted LF reproduction at a very high SPL. For optimum results we recommend amplifiers able to deliver 3000 Watt program power. The 21NLW4100 features a unique motor featuring a high grade neo magnet assembly in a structure optimized for thermal and magnetic efficiency. 21NLW4100 features include a large displacement suspension system which, in conjunction with a composite reinforced, straight ribbed cone allows an ultra-linear piston action and provides full mechanical control across the entire working range. The 100mm (4 in) state-of-the-art voice-coil utilizing Interleaved Sandwich Voice coil (ISV) technology, provides high levels of thermal stability and durability. The ISV technology achieves a balanced linear motor unit exerting an exceptionally high force factor.




Mounting and Shipping Info

  • Nominal Diameter533 mm ( in)
  • Nominal Impedance4 Ω
  • Minimum Impedance3.2 Ω
  • Nominal Power Handling11500 W
  • Continuous Power Handling23000 W
  • Sensitivity397.0 dB
  • Frequency Range32 - 300 Hz
  • Voice Coil Diameter100 mm (4.0 in)
  • Winding Materialcopper
  • Winding Depth36.5 mm (1.44 in)
  • Magnetic Gap Depth12.4 mm (0.49 in)
  • Surround ShapeTriple roll
  • Cone ShapeCurvilinear
  • Magnet MaterialNeo
  • Woofer Cone TreatmentReinforced, water repellent, treated paper
  • Recommended Enclosure250.0 dm3 (8.83 ft3)
  • Recommended Tuning33 Hz
  • Resonance Frequency34 Hz
  • Re2.6 Ω
  • Qes0.42
  • Qms7.8
  • Qts0.4
  • Vas219.0 dm3 (7.73 ft3)
  • Sd1661.0 cm2 (257.46 in2)
  • η₀1.9 %
  • Xmax15.2 mm
  • Xvar16.0 mm
  • Mms400.0 g
  • Bl22.8 Txm
  • Le1.5 mH
  • EBP80 Hz
  • Overall Diameter545 mm (21.46 in)
  • Bolt Circle Diameter520 mm (20.47 in)
  • Baffle Cutout Diameter492.0 mm (19.37 in)
  • Depth245 mm (9.65 in)
  • Flange and Gasket Thickness24 mm (0.94 in)
  • Net Weight10.5 kg (23.15 lb)
  • Shipping Weight12.0 kg (26.46 lb)
  • Shipping Box570x570x290 mm (22.44x22.44x11.42 in)
  • 2 hours test made with continuous pink noise signal within the range Fs-10Fs. Power calculated on rated minimum impedance. Loudspeaker in free air.
  • Power on Continuous Program is defined as 3 dB greater than the Nominal rating.
  • Applied RMS Voltage is set to 2.83 V for 8 ohms Nominal Impedance.
  • Credits
  • Privacy Policy
  • Eighteen Sound P.IVA/VAT IT02577810357