Bomber Carbon 250W 4 Ohm (SW12CB-250-4)

12″ subwoofer · 4 Ω · 250 W RMS

Fs 34 HzQts 1.20Vas 2.40 ft³Xmax 0.28″

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 volume1.84 ft³ (52 L)
Qtc1.83
Fc52 Hz
F3 (−3 dB, no cabin gain)36 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 3/16″
Open sealed box in designer

Ported

Net volume3.14 ft³ (89 L)
Tuning (Fb)43 Hz
Portslot 1 9/16 × 14 5/16″, 6 7/16″ long
Port velocity at 250 W62 ft/s
F3 (−3 dB, no cabin gain)34 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 14 7/8″
Open ported box in designer
2030405060801001502007278849096102HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs34 Hz
Qts1.20
Qes1.41
Qms8.21
Vas2.40 ft³
Re3.77 Ω
Sd81.1 in²
Xmax0.28″
Vd22.3 in³ calc.
Mms125 g calc.
BL8.4 T·m calc.
EBP24 — suits sealed calc.
Sensitivity, 1 W / 1 m84.8 dB calc.

General

Size12″
Voice coils4 Ω
RMS power250 W

Mounting dimensions

Ø13 1/16″cutout ≈ Ø11 3/4″mounting depth 5 3/8″magnet Ø5 1/4″
Cutout diameter≈ 11 3/4″
Mounting depth5 3/8″
Overall diameter13 1/16″
Magnet diameter5 1/4″

“≈” 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 Bomber 12″ models