Rockford Fosgate Prime R1S4-12

12″ subwoofer · 4 Ω · 200 W RMS

30.5 HzFs, resonance
0.54Qts
3.19 ft³Vas
0.28″Xmax
200 WRMS

Recommended box

For a sedan, one sub, 200 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

smaller, tighter
1.87 ft³ (53 L)
Net volume
Qtc0.89
Fc50 Hz
F3 (−3 dB, no cabin gain)44 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 3/8″
Open sealed box in designer

Ported

deeper, louder
3.18 ft³ (90 L)
Net volume
Tuning (Fb)35 Hz
Portslot 1 9/16 × 14 5/16″, 11 9/16″ long
Port velocity at 200 W55 ft/s
F3 (−3 dB, no cabin gain)32 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 15 7/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs30.5 Hz
Qts0.54
Qes0.58
Qms7.97
Vas3.19 ft³
Re3.5 Ω
Sd82.3 in²
Xmax0.28″
Vd22.7 in³ calc.
Mms120 g calc.
BL11.8 T·m calc.
EBP53 — sealed or ported calc.
Sensitivity, 1 W / 1 m88.5 dB calc.

General

Size12″
Voice coils4 Ω
RMS power200 W

Mounting dimensions

Ø≈ 12 3/8″cutout Ø11 1/4″mounting depth 4 15/16″magnet Ø≈ 7 5/16″
Cutout diameter11 1/4″
Mounting depth4 15/16″

“≈” 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