Fountek FR89EX

• Sensitivity (1W, 1m, infinite baffle) SPL1W 85.1dB
• Frequency response 70 - 20000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 97Hz
• Mechanical quality factor QMS 4.89
• Electrical quality factor QES 0.58
• Total quality factor QTS 0.52

Large signal parameters

• Maximum linear excursion xmax 5mm
• Air volume displaced at xmax VD 14cm³
• Power handling P 25W
• Program power Pmax 50W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.8Ω
• Inductance (1kHz, estimated) LE 0.22mH
• VC Diameter 25mm
• Winding height HVC 5mm
• Winding material Copper
• Former material Kapton

Magnet

• Flux density B 0.85T
• Force factor Bl 3.69N/A
• Motor constant Bl/√RE 1.53N/√W
• Air gap height HAG 14mm
• Material Neodymium

Diaphragm

• Effective diameter 60mm
• Effective area SD 28.3cm²
• Moving mass MMS 2.19g
• Moving mass (without air load) MMD 2.1g

Suspensions

• Stiffness KMS 0.822N/mm
• Compliance CMS 1217µm/N
• Equivalent volume to the compliance VAS 1.4L
• Mechanical resistance RMS 0.27N·s/m

Dimensions

• Nominal diameter 3.5″
• 89mm
• Overall diameter 88mm
• Overall depth 47mm
• Volume occupied by the driver (estimated) 0.12L
• Net weight 0.525kg