Fi Car Audio IB318 v2 S4

• Sensitivity (1W, 1m, infinite baffle) SPL1W 88.7dB

Thiele & Small parameters

• Resonance frequency (free air) fS 24.4Hz
• Mechanical quality factor QMS 9.56
• Electrical quality factor QES 0.87
• Total quality factor QTS 0.79

Large signal parameters

• Maximum linear excursion xmax 34mm
• Air volume displaced at xmax VD 4114cm³
• Power handling P 600W
• Program power Pmax 1200W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.6Ω
• Inductance (1kHz, estimated) LE 3.85mH

Magnet

• Force factor Bl 15N/A
• Motor constant Bl/√RE 7.91N/√W

Diaphragm

• Effective diameter 393mm
• Effective area SD 1210cm²
• Moving mass MMS 338g
• Moving mass (without air load) MMD 308g

Suspensions

• Stiffness KMS 8.33N/mm
• Compliance CMS 120µm/N
• Equivalent volume to the compliance VAS 246L
• Mechanical resistance RMS 5.42N·s/m

Dimensions

• Nominal diameter 18″
• 470mm
• Overall diameter 470mm
• Baffle cutout diameter 425mm
• Mounting depth 241mm
• Volume occupied by the driver 6.23L