Fi Car Audio SP4 15v2+ D1

• Sensitivity (1W, 1m, infinite baffle) SPL1W 88.5dB

Thiele & Small parameters

• Resonance frequency (free air) fS 27.5Hz
• Mechanical quality factor QMS 8.76
• Electrical quality factor QES 0.33
• Total quality factor QTS 0.32

Large signal parameters

• Maximum linear excursion xmax 33mm
• Air volume displaced at xmax VD 2673cm³
• Power handling P 3500W
• Program power Pmax 7000W

Voice Coil

• Nominal impedance Z 2 x 1Ω
• DC resistance (in series) RE 1.3Ω
• Inductance (1kHz, in series, estimated) LE 1.65mH

Magnet

• Force factor (in series) Bl 17.2N/A
• Motor constant Bl/√RE 15.1N/√W

Diaphragm

• Effective diameter 321mm
• Effective area SD 810cm²
• Moving mass MMS 438g
• Moving mass (without air load) MMD 421g

Suspensions

• Stiffness KMS 12.8N/mm
• Compliance CMS 78.4µm/N
• Equivalent volume to the compliance VAS 71L
• Mechanical resistance RMS 8.64N·s/m

Dimensions

• Nominal diameter 15″
• 397mm
• Overall diameter 397mm
• Baffle cutout diameter 359mm
• Mounting depth 279mm
• Volume occupied by the driver 5.95L