Fi Car Audio SP4 15 D1

• Sensitivity (1W, 1m, infinite baffle) SPL1W 86.9dB

Thiele & Small parameters

• Resonance frequency (free air) fS 27.6Hz
• Mechanical quality factor QMS 6.56
• Electrical quality factor QES 0.52
• Total quality factor QTS 0.48

Large signal parameters

• Maximum linear excursion xmax 33mm
• Air volume displaced at xmax VD 2673cm³
• Power handling P 3000W
• Program power Pmax 6000W

Voice Coil

• Nominal impedance Z 2 x 1Ω
• DC resistance (in series) RE 1.3Ω
• Inductance (1kHz, in series, estimated) LE 1.64mH

Magnet

• Force factor (in series) Bl 13.7N/A
• Motor constant Bl/√RE 12N/√W

Diaphragm

• Effective diameter 321mm
• Effective area SD 810cm²
• Moving mass MMS 434g
• Moving mass (without air load) MMD 417g

Suspensions

• Stiffness KMS 13N/mm
• Compliance CMS 77µm/N
• Equivalent volume to the compliance VAS 70.4L
• Mechanical resistance RMS 11.5N·s/m

Dimensions

• Nominal diameter 15″
• 397mm
• Overall diameter 397mm
• Baffle cutout diameter 359mm
• Mounting depth 286mm
• Volume occupied by the driver 5.95L