Rockford Fosgate Prime R2D4-12

12″ subwoofer · dual 4 Ω · 250 W RMS

Fs 34.9 HzQts 0.61Vas 2.43 ft³Xmax 0.26″

Recommended box

For a sedan, one sub, 250 W. It’s the same math as the designer’s step-by-step mode, where you can fit the box to your space, vehicle and amp and get plans, a cut sheet and DXF.

Sealed

Net volume1.91 ft³ (54 L)
Qtc0.91
Fc53 Hz
F3 (−3 dB, no cabin gain)45 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 1/2″
Open sealed box in designer

Ported

Net volume3.25 ft³ (92 L)
Tuning (Fb)37 Hz
Portslot 1 9/16 × 14 5/16″, 9 5/8″ long
Port velocity at 250 W65 ft/s
F3 (−3 dB, no cabin gain)33 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 15 9/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs34.9 Hz
Qts0.61
Qes0.66
Qms7.33
Vas2.43 ft³
Re (one coil)3.59 Ω
Sd83.6 in²
Xmax0.26″
Vd21.4 in³ calc.
Mms124 g calc.
BL12.2 T·m calc.
EBP53 — sealed or ported calc.
Sensitivity, 1 W / 1 m88.5 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power250 W

Mounting dimensions

Ø≈ 12 3/8″cutout Ø11 1/4″mounting depth 5 1/16″magnet Ø≈ 7 5/16″
Cutout diameter11 1/4″
Mounting depth5 1/16″

“≈” means the value isn’t in the spec sheet and a typical value for the size is used; “calc.” means it’s calculated from the published parameters. Check the manufacturer’s spec sheet before you build.

Data sources

Other Rockford Fosgate 12″ models