B&C Speaker 8FMB51

• Sensitivity (1W, 1m, infinite baffle) SPL1W 94.3dB
• Frequency response 67 - 4500Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 67Hz
• Mechanical quality factor QMS 3.07
• Electrical quality factor QES 0.31
• Total quality factor QTS 0.28

Large signal parameters

• Maximum linear excursion xmax 5.5mm
• Air volume displaced at xmax VD 125cm³
• Power handling P 250W
• Program power Pmax 500W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 4.7Ω
• Inductance (1kHz) LE 0.48mH
• VC Diameter 51mm
• Winding height HVC 15mm
• Winding material Aluminium
• Former material Glass Fibre

Magnet

• Flux density B 1.19T
• Force factor Bl 11.3N/A
• Motor constant Bl/√RE 5.21N/√W
• Air gap height HAG 8mm
• Material Ferrite

Diaphragm

• Effective diameter 170mm
• Effective area SD 227cm²
• Moving mass MMS 20.2g
• Moving mass (without air load) MMD 17.6g
• Material Waterproof

Suspensions

• Stiffness KMS 3.55N/mm
• Compliance CMS 282µm/N
• Equivalent volume to the compliance VAS 20.7L
• Mechanical resistance RMS 2.77N·s/m

Dimensions

• Nominal diameter 8″
• 200mm
• Overall diameter 225mm
• Baffle cutout diameter 187mm
• Overall depth 92mm
• Flange thickness 9mm
• Mounting depth 83mm
• Volume occupied by the driver 1.2L
• Net weight 3.4kg