Rockford Fosgate PM212S4

• Sensitivity (1W, 1m, infinite baffle) SPL1W 83.1dB

Thiele & Small parameters

• Resonance frequency (free air) fS 25.5Hz
• Mechanical quality factor QMS 9.00
• Electrical quality factor QES 0.55
• Total quality factor QTS 0.52

Large signal parameters

• Maximum linear excursion xmax 12mm
• Air volume displaced at xmax VD 612cm³
• Power handling P 300W
• Program power Pmax 600W

Voice Coil

• Nominal impedance Z 4Ω
• DC resistance RE 3.1Ω
• Inductance (1kHz) LE 0.3mH
• VC Diameter 51mm
• Former material Aluminum

Magnet

• Force factor Bl 17.1N/A
• Motor constant Bl/√RE 9.71N/√W
• Weight 0.08kg

Diaphragm

• Effective diameter 255mm
• Effective area SD 510cm²
• Moving mass MMS 325g
• Moving mass (without air load) MMD 316g

Suspensions

• Stiffness KMS 8.33N/mm
• Compliance CMS 120µm/N
• Equivalent volume to the compliance VAS 44.3L
• Mechanical resistance RMS 5.78N·s/m

Dimensions

• Nominal diameter 12″
• 305mm
• Baffle cutout diameter 278mm
• Mounting depth 155mm
• Volume occupied by the driver 7.31L