8 Inch (203 mm), 8 Ohm Whizzer Speaker with 4 Watt Transformer

Brand Name
Oaktron by MISCO
Model #
Part #
In stock

The OK8-T74 is a commercial extended range speaker with an attached 4 watt transformer for paging systems, voice communications, and background music applications. Increase your sound system's high frequency dispersion with this driver's whizzer cone attached directly to the voice coil. 

  • Extended range speaker with whizzer
  • 8" (203 mm) steel basket diameter
  • 15 watts, 8 ohm, 90 dB SPL
  • 4 watt, 70 volt transformer
  • 1" copper voice coil, aluminum former
  • Paper cone and whizzer, ferrite magnet

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More Information
Brand Name Oaktron by MISCO
Model # OK8-T74
Size, Nominal (inch & mm) 8" (203 mm)
Shape of Speaker Round
Speaker Type Wide Range
Application Commercial, Indoor, Voice Communications
Environment Indoor
RoHS Compliant No
Nominal Impedance (Z) (Ω) 8
Rated Power IEC268-5 (W) 15 Watts
Rated Impedance (Ω) 8
Continuous Power (W) 15
Program Power (W) 30
Frequency Range (Hz) 40 - 18,000
Sensitivity (dB SPL) ¹ 90
Resonant Frequency (Fs) (Hz) +/- 15% 90
DC Resistance (Re) (Ω) 7.3
Voice Coil Inductance (Le) (mH) 0.27
Mechanical Q Factor (Qms) 9.28
Electrical Q Factor (Qes) 0.87
Total Q Factor (Qts) 0.79
Mechanical Resistance (Rms) (kg/s) 0.47
Compliance Equivalent Volume (Vas) (L) 15.5
Suspension Compliance (Cms) (mm/N) 0.39
Surface Area of Diaphragm (Sd) (cm²) 219.0
Moving Mass (Mms) (gm) 7.53
Maximum Linear Excursion (Xmax) (mm) 1.1
Motor Force Factor (BL) (T•M) 6.08
Efficiency (η₀) (%) 2.6
Efficiency Bandwidth Product (EBP) (Fs/Qes) 103.45
Basket Type Stamped steel
Terminal Size (mm) 4.8 x 0.5
Voice Coil Diameter (mm) 25.4
Voice Coil Wire Material Copper
Voice Coil Former Material Aluminum
Voice Coil Winding Single Layer
Magnet Material Ferrite
Magnet Weight (g) 283.5
Cone Body Material Paper composite
Dust Cap Material Paper whizzer
Spider Material Cotton
Net Weight (kg) 0.9
Technical Notes

¹ Sensitivity is measure with 2.83 volt input, measured on-axis at 1 meter distance