Alpine SWE-1243E (Type-E)

12″ subwoofer · 4 Ω · 250 W RMS

Fs 28 HzQts 0.38Vas 2.65 ft³Xmax 0.39″

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 volume0.78 ft³ (22 L)
Qtc0.80
Fc59 Hz
F3 (−3 dB, no cabin gain)56 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)31 Hz
Portslot 1 9/16 × 14 5/16″, 21 1/2″ long
Port velocity at 250 W53 ft/s
F3 (−3 dB, no cabin gain)30 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 13 1/4″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs28 Hz
Qts0.38
Qes0.43
Qms3.27
Vas2.65 ft³
Re3.6 Ω
Sd77.8 in²
Xmax0.39″
Vd30.6 in³ calc.
Mms154 g calc.
BL15 T·m calc.
EBP65 — sealed or ported calc.
Sensitivity, 1 W / 1 m87.8 dB calc.

General

Size12″
Voice coils4 Ω
RMS power250 W

Mounting dimensions

Ø≈ 12 5/16″cutout Ø11 1/8″mounting depth 6 5/8″magnet Ø≈ 7 3/16″
Cutout diameter11 1/8″
Mounting depth6 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