Eighteen Sound 12MB650

• Sensitivity (1W, 1m, infinite baffle) SPL1W 97.5dB
• Frequency response 45 - 5000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 48Hz
• Mechanical quality factor QMS 3.20
• Electrical quality factor QES 0.24
• Total quality factor QTS 0.23

Large signal parameters

• Maximum linear excursion xmax 5.5mm
• Air volume displaced at xmax VD 292cm³
• Power handling P 400W
• Program power Pmax 800W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 6.0Ω
• Inductance (1kHz) LE 0.83mH
• VC Diameter 65mm
• Winding material Aluminum

Magnet

• Force factor Bl 19N/A
• Motor constant Bl/√RE 7.76N/√W
• Material Ferrite

Diaphragm

• Effective diameter 260mm
• Effective area SD 531cm²
• Moving mass MMS 48g
• Moving mass (without air load) MMD 39.4g
• Material Weather protected

Suspensions

• Stiffness KMS 4.37N/mm
• Compliance CMS 229µm/N
• Equivalent volume to the compliance VAS 90L
• Mechanical resistance RMS 4.52N·s/m

Dimensions

• Nominal diameter 12″
• 300mm
• Overall diameter 310mm
• Baffle cutout diameter 280mm
• Overall depth 143mm
• Flange thickness 14mm
• Mounting depth 129mm
• Volume occupied by the driver (estimated) 2.9L
• Net weight 6.8kg