BMS 12N820

• Sensitivity (1W, 1m, infinite baffle) SPL1W 96.8dB
• Frequency response 45 - 1700Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 37.8Hz
• Mechanical quality factor QMS 5.30
• Electrical quality factor QES 0.16
• Total quality factor QTS 0.16

Large signal parameters

• Maximum linear excursion xmax 4.5mm
• Air volume displaced at xmax VD 239cm³
• Power handling P 800W
• Program power Pmax 1600W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.7Ω
• Inductance (1kHz) LE 0.62mH
• VC Diameter 101.6mm
• Winding height HVC 19mm
• Winding material Copper

Magnet

• Force factor Bl 24.2N/A
• Motor constant Bl/√RE 10.1N/√W
• Air gap height HAG 10mm
• Material Neodymium

Diaphragm

• Effective diameter 260mm
• Effective area SD 531cm²
• Moving mass MMS 72g
• Moving mass (without air load) MMD 63.2g

Suspensions

• Stiffness KMS 4N/mm
• Compliance CMS 250µm/N
• Equivalent volume to the compliance VAS 98.7L
• Mechanical resistance RMS 3.23N·s/m

Dimensions

• Nominal diameter 12″
• 318mm
• Overall diameter 318mm
• Baffle cutout diameter 284mm
• Overall depth 155mm
• Volume occupied by the driver (estimated) 2.7L
• Net weight 5.5kg
• Frame material Cast Aluminum