Tang Band W4-639SE

• Sensitivity (1W, 1m, infinite baffle) SPL1W 85.9dB
• Frequency response 70 - 7000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 70Hz
• Mechanical quality factor QMS 3.70
• Electrical quality factor QES 0.54
• Total quality factor QTS 0.47

Large signal parameters

• Maximum linear excursion xmax 3.2mm
• Air volume displaced at xmax VD 18cm³
• Power handling P 25W
• Program power Pmax 50W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 6.0Ω
• Inductance (1kHz) LE 0.167mH
• VC Diameter 25.4mm

Magnet

• Force factor Bl 5.51N/A
• Motor constant Bl/√RE 2.25N/√W
• Air gap height HAG 5mm
• Material Ferrite

Diaphragm

• Effective diameter 85mm
• Effective area SD 57cm²
• Moving mass MMS 6g
• Moving mass (without air load) MMD 5.7g
• Material Kevlar Fiber

Suspensions

• Stiffness KMS 1.23N/mm
• Compliance CMS 811µm/N
• Equivalent volume to the compliance VAS 3.74L
• Mechanical resistance RMS 0.71N·s/m
• Surround material Rubber

Dimensions

• Nominal diameter 4″
• 102mm
• Volume occupied by the driver (estimated) 0.14L