Eighteen Sound 6NMB420 16Ω

• Sensitivity (1W, 1m, infinite baffle) SPL1W 92.9dB
• Frequency response 200 - 6300Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 112Hz
• Mechanical quality factor QMS 3.42
• Electrical quality factor QES 0.46
• Total quality factor QTS 0.40

Large signal parameters

• Maximum linear excursion xmax 3mm
• Air volume displaced at xmax VD 39cm³
• Power handling P 200W
• Program power Pmax 260W

Voice Coil

• Nominal impedance Z 16Ω
• DC resistance RE 10.6Ω
• Inductance (1kHz) LE 0.15mH
• VC Diameter 44mm
• Winding material Aluminum

Magnet

• Force factor Bl 9N/A
• Motor constant Bl/√RE 2.76N/√W
• Material Neodymium

Diaphragm

• Effective diameter 129mm
• Effective area SD 130cm²
• Moving mass MMS 8.5g
• Moving mass (without air load) MMD 7.4g
• Material Weather protected

Suspensions

• Stiffness KMS 4.2N/mm
• Compliance CMS 238µm/N
• Equivalent volume to the compliance VAS 5.9L
• Mechanical resistance RMS 1.75N·s/m

Dimensions

• Nominal diameter 6.5″
• 152mm
• Overall diameter 162mm
• Baffle cutout diameter 148mm
• Overall depth 73mm
• Flange thickness 11mm
• Mounting depth 62mm
• Volume occupied by the driver (estimated) 0.41L
• Net weight 1.25kg