Alpine SWR-12D4 (Type-R)

12″ subwoofer · dual 4 Ω · 1,000 W RMS

Fs 28 HzQts 0.48Vas 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 volume0.92 ft³ (26 L)
Qtc0.80
Fc47 Hz
F3 (−3 dB, no cabin gain)44 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 12 5/16″
Open sealed box in designer

Ported

Net volume2.86 ft³ (81 L)
Tuning (Fb)26 Hz
Portslot 2 3/4 × 14 5/16″, 49 3/8″ long
Port velocity at 1,000 W65 ft/s
F3 (−3 dB, no cabin gain)24 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 18 3/4″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs28 Hz
Qts0.48
Qes0.52
Qms6.04
Vas1.62 ft³
Re (one coil)3.8 Ω
Sd74.2 in²
Xmax0.79″
Vd58.5 in³ calc.
Mms228 g calc.
BL17.1 T·m calc.
EBP54 — sealed or ported calc.
Sensitivity, 1 W / 1 m84.9 dB calc.

General

Size12″
Voice coilsdual 4 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