Bomber Upgrade 350W 4 Ohm (SW8UP-350-4)

8″ subwoofer · 4 Ω · 350 W RMS

34 HzFs, resonance
0.37Qts
1.36 ft³Vas
0.37″Xmax
350 WRMS

Recommended box

For a sedan, one sub, 350 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

smaller, tighter
0.35 ft³ (10 L)
Net volume
Qtc0.81
Fc75 Hz
F3 (−3 dB, no cabin gain)71 Hz
Example box (outside)10 5/8″ × 10 5/8″ × 9 5/16″
Open sealed box in designer

Ported

deeper, louder
1.17 ft³ (33 L)
Net volume
Tuning (Fb)38 Hz
Portslot 1 9/16 × 14 5/16″, 31 15/16″ long
Port velocity at 350 W48 ft/s
F3 (−3 dB, no cabin gain)37 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 8 9/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs34 Hz
Qts0.37
Qes0.41
Qms3.51
Vas1.36 ft³
Re3.3 Ω
Sd31.9 in²
Xmax0.37″
Vd11.9 in³ calc.
Mms34 g calc.
BL7.7 T·m calc.
EBP83 — sealed or ported calc.
Sensitivity, 1 W / 1 m87.7 dB calc.

General

Size8″
Voice coils4 Ω
RMS power350 W

Mounting dimensions

Ø8 5/16″cutout ≈ Ø7 1/2″mounting depth 4 5/8″magnet Ø5 1/4″
Cutout diameter≈ 7 1/2″
Mounting depth4 5/8″
Overall diameter8 5/16″
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 8″ models