Eighteen Sound 15NMB420

• Sensitivity (1W, 1m, infinite baffle) SPL1W 99.4dB
• Frequency response 40 - 5000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 42Hz
• Mechanical quality factor QMS 6.00
• Electrical quality factor QES 0.30
• Total quality factor QTS 0.29

Large signal parameters

• Maximum linear excursion xmax 6.5mm
• Air volume displaced at xmax VD 585cm³
• Power handling P 450W
• Program power Pmax 700W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.6Ω
• Inductance (1kHz) LE 0.8mH
• VC Diameter 75mm
• Winding material Aluminum

Magnet

• Force factor Bl 19N/A
• Motor constant Bl/√RE 8.03N/√W
• Material Neodymium

Diaphragm

• Effective diameter 339mm
• Effective area SD 900cm²
• Moving mass MMS 73g
• Moving mass (without air load) MMD 54.7g
• Material Weather protected

Suspensions

• Stiffness KMS 5.08N/mm
• Compliance CMS 197µm/N
• Equivalent volume to the compliance VAS 225L
• Mechanical resistance RMS 3.21N·s/m

Dimensions

• Nominal diameter 15″
• 380mm
• Overall diameter 387mm
• Baffle cutout diameter 353mm
• Overall depth 169mm
• Flange thickness 11mm
• Mounting depth 158mm
• Volume occupied by the driver (estimated) 2.6L
• Net weight 3.9kg