Celestion CF0820BMB

• Sensitivity (1W, 1m, infinite baffle) SPL1W 90.2dB
• Frequency response 50 - 6000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 50.5Hz
• Mechanical quality factor QMS 5.10
• Electrical quality factor QES 0.39
• Total quality factor QTS 0.37

Large signal parameters

• Maximum linear excursion xmax 7.3mm
• Air volume displaced at xmax VD 165cm³
• Power handling P 250W
• Program power Pmax 500W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.5Ω
• Inductance (1kHz) LE 0.78mH
• VC Diameter 50mm
• Winding height HVC 18.5mm
• Winding material Copper clad aluminium
• Former material Glass fibre

Magnet

• Force factor Bl 11.9N/A
• Motor constant Bl/√RE 5.11N/√W
• Air gap height HAG 8mm
• Weight 0.99kg
• Material Ferrite

Diaphragm

• Effective diameter 170mm
• Effective area SD 227cm²
• Moving mass MMS 32.4g
• Moving mass (without air load) MMD 29.8g
• Material Treated paper

Suspensions

• Stiffness KMS 3.23N/mm
• Compliance CMS 310µm/N
• Equivalent volume to the compliance VAS 22.4L
• Mechanical resistance RMS 2.01N·s/m
• Surround material Elastomer

Dimensions

• Nominal diameter 8″
• 200mm
• Overall diameter 215mm
• Baffle cutout diameter 187mm
• Overall depth 108mm
• Volume occupied by the driver (estimated) 1.1L
• Net weight 3.1kg
• Frame material Cast aluminium