Eminence SIGMA PRO-18A-2

• Sensitivity (1W, 1m, infinite baffle) SPL1W 96.2dB
• Frequency response 41 - 2400Hz

Thiele & Small parameters

• Resonance frequency (free air) fS 28Hz
• Mechanical quality factor QMS 8.28
• Electrical quality factor QES 0.30
• Total quality factor QTS 0.29

Large signal parameters

• Maximum linear excursion xmax 6.1mm
• Maximum excursion before damage xlim 18mm
• Air volume displaced at xmax VD 695cm³
• Power handling P 650W
• Program power Pmax 1300W

Voice Coil

• Nominal impedance Z 8Ω
• DC resistance RE 6.3Ω
• Inductance (1kHz) LE 1.9mH
• VC Diameter 76.2mm
• Winding material Copper
• Former material Polyimide

Magnet

• Force factor Bl 22.1N/A
• Motor constant Bl/√RE 8.81N/√W
• Air gap height HAG 9.5mm
• Weight 3.402kg
• Material Ferrite

Diaphragm

• Effective diameter 381mm
• Effective area SD 1140cm²
• Moving mass MMS 130g
• Moving mass (without air load) MMD 103g
• Material Paper

Suspensions

• Stiffness KMS 4.17N/mm
• Compliance CMS 240µm/N
• Equivalent volume to the compliance VAS 441L
• Mechanical resistance RMS 2.76N·s/m
• Surround material Cloth

Dimensions

• Nominal diameter 18″
• 457mm
• Overall diameter 457mm
• Baffle cutout diameter 421mm
• Overall depth 207mm
• Volume occupied by the driver 6.63L
• Net weight 11.113kg
• Frame material Die-cast Aluminium