Alpine SWR-12D2 (Type-R)

12″ subwoofer · dual 2 Ω · 1,000 W RMS

Fs 27 HzQts 0.44Vas 1.62 ft³Xmax 0.79″

Recommended box

For a sedan, one sub, 1,000 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 volume0.71 ft³ (20 L)
Qtc0.80
Fc49 Hz
F3 (−3 dB, no cabin gain)47 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 10 1/16″
Open sealed box in designer

Ported

Net volume2.33 ft³ (66 L)
Tuning (Fb)27 Hz
Portslot 2 9/16 × 14 5/16″, 52 11/16″ long
Port velocity at 1,000 W64 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 16 11/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs27 Hz
Qts0.44
Qes0.47
Qms7.1
Vas1.62 ft³
Re (one coil)1.95 Ω
Sd74.2 in²
Xmax0.79″
Vd58.5 in³ calc.
Mms245 g calc.
BL13.1 T·m calc.
EBP57 — sealed or ported calc.
Sensitivity, 1 W / 1 m84.9 dB calc.

General

Size12″
Voice coilsdual 2 Ω
RMS power1,000 W

Mounting dimensions

Ø12 5/8″cutout Ø10 13/16″mounting depth 6 3/8″magnet Ø≈ 7 1/16″
Cutout diameter10 13/16″
Mounting depth6 3/8″
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