Oberton 18B35

• Sensitivity (1W, 1m, infinite baffle) SPL1W 97.4dB
• Frequency response 32 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 31.8Hz
• Mechanical quality factor QMS 8.05
• Electrical quality factor QES 0.34
• Total quality factor QTS 0.32

Large signal parameters

• Maximum linear excursion xmax 9mm
• Air volume displaced at xmax VD 999cm³
• Power handling P 700W
• Program power Pmax 1400W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 4.9Ω
• Inductance (1kHz) LE 0.61mH
• VC Diameter 88mm
• Winding height HVC 24mm
• Winding material Copper Clad Aluminium
• Former material Glass fiber

Magnet

• Flux density B 1.06T
• Force factor Bl 19.3N/A
• Motor constant Bl/√RE 8.75N/√W
• Air gap height HAG 12mm
• Material Ferrite

Diaphragm

• Effective diameter 376mm
• Effective area SD 1110cm²
• Moving mass MMS 130g
• Moving mass (without air load) MMD 103g
• Material Paper

Suspensions

• Stiffness KMS 5.16N/mm
• Compliance CMS 194µm/N
• Equivalent volume to the compliance VAS 334L
• Mechanical resistance RMS 3.21N·s/m

Dimensions

• Nominal diameter 18″
• 461mm
• Overall diameter 461mm
• Baffle cutout diameter 417mm
• Overall depth 196mm
• Volume occupied by the driver (estimated) 5.8L
• Net weight 10.0kg
• Frame material Die cast aluminium