Eighteen Sound 15NCX750H

• Sensitivity (1W, 1m, infinite baffle) SPL1W 98.6dB
• Frequency response 50 - 4700Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 49Hz
• Mechanical quality factor QMS 6.32
• Electrical quality factor QES 0.40
• Total quality factor QTS 0.37

Large signal parameters

• Maximum linear excursion xmax 5.5mm
• Air volume displaced at xmax VD 485cm³
• Power handling P 400W
• Program power Pmax 800W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 5.4Ω
• Inductance (1kHz) LE 0.66mH
• VC Diameter 75mm
• Winding material Copper

Magnet

• Force factor Bl 18.5N/A
• Motor constant Bl/√RE 7.96N/√W
• Material Neodymium

Diaphragm

• Effective diameter 335mm
• Effective area SD 881cm²
• Moving mass MMS 80.6g
• Moving mass (without air load) MMD 62.4g
• Material Water repellent

Suspensions

• Stiffness KMS 7.63N/mm
• Compliance CMS 131µm/N
• Equivalent volume to the compliance VAS 141L
• Mechanical resistance RMS 3.93N·s/m

Dimensions

• Nominal diameter 15″
• 380mm
• Overall diameter 393mm
• Baffle cutout diameter 360mm
• Overall depth 185mm
• Flange thickness 14mm
• Mounting depth 171mm
• Volume occupied by the driver (estimated) 3.4L
• Net weight 5.3kg