Fostex FW108HS

• Sensitivity (1W, 1m, infinite baffle) SPL1W 84.8dB
• Frequency response 65 - 15000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 65Hz
• Mechanical quality factor QMS 8.78
• Electrical quality factor QES 0.49
• Total quality factor QTS 0.46

Large signal parameters

• Maximum linear excursion xmax 1.6mm
• Air volume displaced at xmax VD 7.8cm³
• Power handling P 20W
• Program power Pmax 50W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 7.2Ω
• Inductance (1kHz) LE 0.48mH
• VC Diameter 30mm

Magnet

• Force factor Bl 5.98N/A
• Motor constant Bl/√RE 2.23N/√W
• Weight 0.5kg
• Material Ferrite

Diaphragm

• Effective diameter 80mm
• Effective area SD 50cm²
• Moving mass MMS 6g
• Moving mass (without air load) MMD 5.7g

Suspensions

• Stiffness KMS 0.995N/mm
• Compliance CMS 1005µm/N
• Equivalent volume to the compliance VAS 3.6L
• Mechanical resistance RMS 0.28N·s/m

Dimensions

• Nominal diameter 4″
• 100mm
• Overall diameter 128mm
• Baffle cutout diameter 105mm
• Overall depth 74mm
• Volume occupied by the driver (estimated) 0.44L
• Net weight 1.7kg