Fostex FE108-Sol 2023

• Sensitivity (1W, 1m, infinite baffle) SPL1W 90.7dB
• Frequency response 70 - 35000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 76.3Hz
• Mechanical quality factor QMS 3.28
• Electrical quality factor QES 0.38
• Total quality factor QTS 0.34

Large signal parameters

• Maximum linear excursion xmax 0.9mm
• Air volume displaced at xmax VD 4.5cm³
• Power handling P 5W
• Program power Pmax 10W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 6.6Ω
• Inductance (1kHz) LE 0.035mH
• VC Diameter 20mm

Magnet

• Force factor Bl 4.95N/A
• Motor constant Bl/√RE 1.93N/√W
• Weight 0.451kg

Diaphragm

• Effective diameter 80mm
• Effective area SD 50cm²
• Moving mass MMS 2.9g
• Moving mass (without air load) MMD 2.6g

Suspensions

• Stiffness KMS 0.667N/mm
• Compliance CMS 1500µm/N
• Equivalent volume to the compliance VAS 5.36L
• Mechanical resistance RMS 0.42N·s/m

Dimensions

• Nominal diameter 4″
• 100mm
• Overall diameter 128mm
• Baffle cutout diameter 103mm
• Volume occupied by the driver (estimated) 0.5L
• Net weight 1.26kg