Fi Car Audio Q18 D2

• Sensitivity (1W, 1m, infinite baffle) SPL1W 89.8dB

Thiele & Small parameters

• Resonance frequency (free air) fS 27.9Hz
• Mechanical quality factor QMS 9.17
• Electrical quality factor QES 0.54
• Total quality factor QTS 0.51

Large signal parameters

• Maximum linear excursion xmax 34mm
• Air volume displaced at xmax VD 4114cm³
• Power handling P 1750W
• Program power Pmax 3500W

Voice Coil

• Nominal impedance Z 2 x 2Ω
• DC resistance (in series) RE 3.6Ω
• Inductance (1kHz, in series, estimated) LE 4.41mH

Magnet

• Force factor (in series) Bl 21.4N/A
• Motor constant Bl/√RE 11.3N/√W

Diaphragm

• Effective diameter 393mm
• Effective area SD 1210cm²
• Moving mass MMS 414g
• Moving mass (without air load) MMD 384g

Suspensions

• Stiffness KMS 12.5N/mm
• Compliance CMS 80.1µm/N
• Equivalent volume to the compliance VAS 164L
• Mechanical resistance RMS 7.91N·s/m

Dimensions

• Nominal diameter 18″
• 476mm
• Overall diameter 476mm
• Baffle cutout diameter 425mm
• Mounting depth 241mm
• Volume occupied by the driver 2.83L