Eighteen Sound 15ND940

• Sensitivity (1W, 1m, infinite baffle) SPL1W 96.7dB
• Frequency response 38 - 3500Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 38Hz
• Mechanical quality factor QMS 7.50
• Electrical quality factor QES 0.29
• Total quality factor QTS 0.28

Large signal parameters

• Maximum linear excursion xmax 7.3mm
• Air volume displaced at xmax VD 621cm³
• Power handling P 100W
• Program power Pmax 500W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.4Ω
• Inductance (1kHz) LE 0.7mH
• VC Diameter 75mm
• Winding height HVC 23.5mm
• Winding material Aluminium

Magnet

• Force factor Bl 21.9N/A
• Motor constant Bl/√RE 9.42N/√W
• Air gap height HAG 9mm
• Material Neodymium

Diaphragm

• Effective diameter 329mm
• Effective area SD 850cm²
• Moving mass MMS 108g
• Moving mass (without air load) MMD 90.5g
• Material Weather protected

Suspensions

• Stiffness KMS 6.14N/mm
• Compliance CMS 163µm/N
• Equivalent volume to the compliance VAS 174L
• Mechanical resistance RMS 3.44N·s/m

Dimensions

• Nominal diameter 15″
• 380mm
• Overall diameter 392mm
• Baffle cutout diameter 354mm
• Overall depth 184mm
• Flange thickness 13mm
• Mounting depth 171mm
• Volume occupied by the driver (estimated) 3.1L
• Net weight 4.7kg