Eighteen Sound 8NMB420 16Ω

• Sensitivity (1W, 1m, infinite baffle) SPL1W 93.5dB
• Frequency response 60 - 5500Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 66Hz
• Mechanical quality factor QMS 3.20
• Electrical quality factor QES 0.47
• Total quality factor QTS 0.41

Large signal parameters

• Maximum linear excursion xmax 5.8mm
• Air volume displaced at xmax VD 132cm³
• Power handling P 280W
• Program power Pmax 400W

Voice Coil

• Nominal impedance Z 16Ω
• DC resistance RE 9.8Ω
• Inductance (1kHz) LE 0.61mH
• VC Diameter 51mm

Magnet

• Force factor Bl 12N/A
• Motor constant Bl/√RE 3.83N/√W

Diaphragm

• Effective diameter 170mm
• Effective area SD 227cm²
• Moving mass MMS 17g
• Moving mass (without air load) MMD 14.5g

Suspensions

• Stiffness KMS 2.92N/mm
• Compliance CMS 342µm/N
• Equivalent volume to the compliance VAS 24.5L
• Mechanical resistance RMS 2.2N·s/m

Dimensions

• Nominal diameter 8″
• 200mm
• Overall diameter 210mm
• Baffle cutout diameter 186mm
• Overall depth 99mm
• Flange thickness 14mm
• Mounting depth 85mm
• Volume occupied by the driver (estimated) 0.72L
• Net weight 1.7kg