Alpine R2-W12D4

12″ subwoofer · dual 4 Ω · 750 W RMS

Fs 30 HzQts 0.51Vas 1.16 ft³Xmax 0.79″

Recommended box

For a sedan, one sub, 750 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 volume0.78 ft³ (22 L)
Qtc0.80
Fc47 Hz
F3 (−3 dB, no cabin gain)45 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 10 13/16″
Open sealed box in designer

Ported

Net volume2.47 ft³ (70 L)
Tuning (Fb)26 Hz
Portslot 2 3/8 × 14 5/16″, 49 3/8″ long
Port velocity at 750 W62 ft/s
F3 (−3 dB, no cabin gain)23 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 16 9/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs30 Hz
Qts0.51
Qes0.55
Qms6.51
Vas1.16 ft³
Re (one coil)3.5 Ω
Sd74.2 in²
Xmax0.79″
Vd58.5 in³ calc.
Mms279 g calc.
BL18.3 T·m calc.
EBP55 — sealed or ported calc.
Sensitivity, 1 W / 1 m84.1 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power750 W

Mounting dimensions

Ø12 5/8″cutout Ø10 7/8″mounting depth 6 7/16″magnet Ø≈ 7 1/16″
Cutout diameter10 7/8″
Mounting depth6 7/16″
Overall diameter12 5/8″

“≈” 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 Alpine 12″ models