Eighteen Sound 18NLW4500

• Sensitivity (1W, 1m, infinite baffle) SPL1W 94.7dB
• Frequency response 30 - 1000Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 37Hz
• Mechanical quality factor QMS 10.80
• Electrical quality factor QES 0.32
• Total quality factor QTS 0.31

Large signal parameters

• Maximum linear excursion xmax 14.8mm
• Air volume displaced at xmax VD 1807cm³
• Power handling P 1800W
• Program power Pmax 3600W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.3Ω
• Inductance (1kHz) LE 1.59mH
• VC Diameter 115mm
• Winding height HVC 36mm
• Winding material Copper

Magnet

• Force factor Bl 26.7N/A
• Motor constant Bl/√RE 14.7N/√W
• Air gap height HAG 13mm
• Material Neodymium

Diaphragm

• Effective diameter 395mm
• Effective area SD 1225cm²
• Moving mass MMS 296g
• Moving mass (without air load) MMD 266g
• Material Weather protected

Suspensions

• Stiffness KMS 15.9N/mm
• Compliance CMS 63µm/N
• Equivalent volume to the compliance VAS 127L
• Mechanical resistance RMS 6.37N·s/m

Dimensions

• Nominal diameter 18″
• 462mm
• Overall diameter 462mm
• Baffle cutout diameter 422mm
• Overall depth 233mm
• Flange thickness 23mm
• Mounting depth 210mm
• Volume occupied by the driver (estimated) 7.3L
• Net weight 12.0kg