Fostex FE108NS

• Sensitivity (1W, 1m, infinite baffle) SPL1W 90.7dB
• Frequency response 75 - 20000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 75Hz
• Mechanical quality factor QMS 3.11
• Electrical quality factor QES 0.35
• Total quality factor QTS 0.32

Large signal parameters

• Power handling P 15W
• Program power Pmax 30W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 7.4Ω
• Inductance (1kHz) LE 0.03mH
• VC Diameter 20mm

Magnet

• Force factor Bl 5.1N/A
• Motor constant Bl/√RE 1.87N/√W

Diaphragm

• Effective diameter 79mm
• Effective area SD 47.2cm²
• Moving mass MMS 2.7g
• Moving mass (without air load) MMD 2.4g

Suspensions

• Stiffness KMS 0.588N/mm
• Compliance CMS 1700µm/N
• Equivalent volume to the compliance VAS 5.37L
• Mechanical resistance RMS 0.41N·s/m

Dimensions

• Nominal diameter 4″
• 100mm
• Overall diameter 128mm
• Baffle cutout diameter 100mm
• Volume occupied by the driver (estimated) 0.43L
• Net weight 1.08kg