Rockford Fosgate R2D4-12

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

Thiele & Small parameters

• Resonance frequency (free air) fS 34.9Hz
• Mechanical quality factor QMS 7.33
• Electrical quality factor QES 0.66
• Total quality factor QTS 0.60

Large signal parameters

• Maximum linear excursion xmax 6.5mm
• Air volume displaced at xmax VD 350cm³
• Power handling P 250W
• Program power Pmax 500W

Voice Coil

• Nominal impedance Z 2 x 4Ω
• DC resistance (in series) RE 7.2Ω
• Inductance (1kHz, in series) LE 3.9mH
• VC Diameter 51mm

Magnet

• Force factor (in series) Bl 17.2N/A
• Motor constant Bl/√RE 6.42N/√W
• Weight 1.35kg

Diaphragm

• Effective diameter 262mm
• Effective area SD 539cm²
• Moving mass MMS 125g
• Moving mass (without air load) MMD 116g

Suspensions

• Stiffness KMS 5.99N/mm
• Compliance CMS 167µm/N
• Equivalent volume to the compliance VAS 68.8L
• Mechanical resistance RMS 3.72N·s/m

Dimensions

• Nominal diameter 12″
• 305mm
• Baffle cutout diameter 285mm
• Mounting depth 128mm
• Volume occupied by the driver 1.3L