Fi Car Audio HT-3 18 S4

• Sensitivity (1W, 1m, infinite baffle) SPL1W 88.9dB

Thiele & Small parameters

• Resonance frequency (free air) fS 21.3Hz
• Mechanical quality factor QMS 6.94
• Electrical quality factor QES 0.45
• Total quality factor QTS 0.42

Large signal parameters

• Maximum linear excursion xmax 34mm
• Air volume displaced at xmax VD 4114cm³
• Power handling P 2000W
• Program power Pmax 4000W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.3Ω
• Inductance (1kHz, estimated) LE 4.48mH

Magnet

• Force factor Bl 21.8N/A
• Motor constant Bl/√RE 12N/√W

Diaphragm

• Effective diameter 393mm
• Effective area SD 1210cm²
• Moving mass MMS 484g
• Moving mass (without air load) MMD 454g

Suspensions

• Stiffness KMS 8.69N/mm
• Compliance CMS 115µm/N
• Equivalent volume to the compliance VAS 236L
• Mechanical resistance RMS 9.33N·s/m

Dimensions

• Nominal diameter 18″
• 470mm
• Overall diameter 470mm
• Baffle cutout diameter 425mm
• Mounting depth 165mm
• Volume occupied by the driver 5.1L