Oberton 8M250

• Sensitivity (1W, 1m, infinite baffle) SPL1W 96.8dB
• Frequency response 90 - 5000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 74.4Hz
• Mechanical quality factor QMS 14.01
• Electrical quality factor QES 0.20
• Total quality factor QTS 0.20

Large signal parameters

• Maximum linear excursion xmax 2.8mm
• Air volume displaced at xmax VD 56cm³
• Power handling P 250W
• Program power Pmax 500W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.0Ω
• Inductance (1kHz) LE 0.42mH
• VC Diameter 51mm
• Winding height HVC 10mm
• Winding material Aluminium
• Former material Kapton

Magnet

• Flux density B 1.43T
• Force factor Bl 13.7N/A
• Motor constant Bl/√RE 6.13N/√W
• Air gap height HAG 9mm
• Material Ferrite

Diaphragm

• Effective diameter 160mm
• Effective area SD 202cm²
• Moving mass MMS 16.4g
• Moving mass (without air load) MMD 14.1g
• Material Paper with glassfiber

Suspensions

• Stiffness KMS 3.57N/mm
• Compliance CMS 280µm/N
• Equivalent volume to the compliance VAS 15.6L
• Mechanical resistance RMS 0.55N·s/m

Dimensions

• Nominal diameter 8″
• 203mm
• Overall diameter 225mm
• Baffle cutout diameter 187mm
• Overall depth 90mm
• Volume occupied by the driver (estimated) 1.3L
• Net weight 4.3kg
• Frame material Die cast aluminium