Oberton 18B500

• Sensitivity (1W, 1m, infinite baffle) SPL1W 96.8dB
• Frequency response 35 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 34.9Hz
• Mechanical quality factor QMS 9.24
• Electrical quality factor QES 0.28
• Total quality factor QTS 0.28

Large signal parameters

• Maximum linear excursion xmax 8.8mm
• Air volume displaced at xmax VD 971cm³
• Power handling P 600W
• Program power Pmax 1200W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.1Ω
• Inductance (1kHz) LE 1.37mH
• VC Diameter 77mm
• Winding height HVC 23mm
• Winding material Copper
• Former material Glass fiber

Magnet

• Flux density B 1.27T
• Force factor Bl 24.1N/A
• Motor constant Bl/√RE 10.7N/√W
• Air gap height HAG 11mm
• Material Ferrite

Diaphragm

• Effective diameter 376mm
• Effective area SD 1110cm²
• Moving mass MMS 147g
• Moving mass (without air load) MMD 120g
• Material Paper

Suspensions

• Stiffness KMS 7.04N/mm
• Compliance CMS 142µm/N
• Equivalent volume to the compliance VAS 244L
• Mechanical resistance RMS 3.48N·s/m

Dimensions

• Nominal diameter 18″
• 461mm
• Overall diameter 461mm
• Baffle cutout diameter 417mm
• Overall depth 202mm
• Volume occupied by the driver (estimated) 6.8L
• Net weight 12.3kg
• Frame material Die cast aluminium