M21WO39-04

Transducer Size (Millimeters)203.2
DC Resistance2.83
Resonant Frequency30.9
Half Space Sensitivity93.79
Rated Noise Power80
Test Spectrum Bandwidth20Hz-10KHz

Transducer Size (Millimeters) 203.2
DC Resistance 2.83 Ω±5.0%
Resonant Frequency 30.9 Hz15%
Half Space Sensitivity @ 2.83V93.79 dB±1.01
Sensitivity @ 1W/1m90.5 dB±1.01
Rated Noise Power (IEC 268-5 18.1)80 W
Test Spectrum Bandwidth 20Hz-10KHz 12 dB/Oc
Effective Piston Area 240.5 cm2
Moving Mass 27.1 g
Motor Force Factor 6.76 T•m
Voice Coil Inner Diameter 38.6 mm
Gap Height 6 mm
Maximum Linear Excursion 5.9 mm
Ferrofluid Type
Minimum Impedance 3.75 Ω±7.5%
Voice Coil Inductance 0.24 mH
Mechanical Q Factor 2.84
Electrical Q Factor 0.33
Total Q Factor 0.29
Ratio 105.8 fs/Qts
Energy Bandwidth Product ((1/Qes)•fs)
Suspension Compliance 980.4 μm/N
Effective Cone Diameter 17.5 cm
Motor Efficiency Factor 16.1 (T•m2)/Ω
Voice Coil Former Material ASV
Transducer Mass 1.86 Kg
Equivalent Volume 79.67 L

This 4 ohm 8 inch driver is a member of the high performance M family. A powerful ferrite magnet system is coupled to a finite element analysis designed suspension system, containing both a linear spider design and a rubber surround.The long-throw voice coil ensures linear high excursion performance, needed for signal clarity. The cone necks are vented so as to reduce air compression effects under high excursion conditions. The cast aluminium basket offers structural rigidity, heat sinking capacity for the motor, and additional air venting under the spider so as to again reduce air compression effects. The cone in this model is a coated paper cone, offering a unique visual and acoustic experience.