4 Inch (100 mm) 8 Ohm Sealed-Back Midrange Speaker

Brand Name
Oaktron by MISCO
Model #
Part #
In stock

A great sealed-back midrange solution as a replacement in old-school 3-way sealed or ported home audio enclosures and PA speakers, as well as high output car audio, that doesn't require a seperate enclosure. This model includes a high power ferrite magnet, a black paper composite cone with a vinyl-edge treatment, and a set of polarized terminals for easy installation into a variety of enclosure sizes.

  • Sealed-back midrange speaker
  • 4" (100 mm) steel basket diameter
  • 50W, 8 Ohm, 92 dB SPL
  • 12 oz ferrite magnet, paper composite cone
  • 1" copper voice coil, Kapton former

MISCO engineers test and analyze the performance of these speakers using the world's most sophisticated loudspeaker measurement systems including the Klippel Analyzer and the Klippel QC, which are used to validate final design. 

Oaktron by MISCO is the premium line of high performance, ready-to-ship transducers for a wide variety of applications including high fidelity, musical instrument, automotive and many more. From elegantly simple to highly specialized designs for unique and demanding applications, there is an Oaktron loudspeaker perfectly suited for your needs.

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More Information
Brand Name Oaktron by MISCO
Model # 100-MR08-01
Size, Nominal (inch & mm) 4" (100 mm)
Shape of Speaker Square
Speaker Type Midrange
Application Home Audio, Voice Communications
Environment Indoor
RoHS Compliant Yes
Nominal Impedance (Z) (Ω) 8
Rated Power IEC268-5 (W) 50 Watts
Rated Impedance (Ω) 8
Continuous Power (W) 50
Program Power (W) 85
Frequency Range (Hz) 330 - 8,000
Sensitivity (dB SPL) ¹ 92
Resonant Frequency (Fs) (Hz) +/- 15% 528
DC Resistance (Re) (Ω) 7.22
Voice Coil Inductance (Le) (mH) 0.01
Mechanical Q Factor (Qms) 7.68
Electrical Q Factor (Qes) 7.00
Total Q Factor (Qts) 3.67
Mechanical Resistance (Rms) (kg/s) 0.25
Compliance Equivalent Volume (Vas) (L) 0.16
Suspension Compliance (Cms) (mm/N) 0.32
Surface Area of Diaphragm (Sd) (cm²) 18.5
Moving Mass (Mms) (gm) 1.20
Motor Force Factor (BL) (T•M) 1.41
Efficiency (η₀) (%) 0.04
Efficiency Bandwidth Product (EBP) (Fs/Qes) 75.46
Basket Type Stamped steel
Terminal Size (mm) 5.2 x 0.5 / 2.8 x 0.5
Voice Coil Diameter (mm) 25.4
Voice Coil Wire Material Copper
Voice Coil Former Material Kapton
Voice Coil Winding Single Layer
Magnet Material Ferrite
Magnet Weight (g) 340.19
Cone Body Material Paper composite
Dust Cap Material Paper
Spider Material Cotton
Net Weight (kg) 0.87
Technical Notes

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