Focal Utopia Be 33 WX2 (SVC 4 ohm)

13″ subwoofer · 4 Ω · 400 W RMS

Fs 32.5 HzQts 0.35Vas 2.58 ft³Xmax 0.35″

Recommended box

For a sedan, one sub, 400 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)
Qtc0.73
Fc68 Hz
F3 (−3 dB, no cabin gain)70 Hz
Example box (outside)14 15/16″ × 14 15/16″ × 9 3/4″
Open sealed box in designer

Ported

Net volume1.91 ft³ (54 L)
Tuning (Fb)38 Hz
Portslot 1 3/4 × 14 5/16″, 20 1/2″ long
Port velocity at 400 W60 ft/s
F3 (−3 dB, no cabin gain)38 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 11 1/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs32.5 Hz
Qts0.35
Qes0.36
Qms11.75
Vas2.58 ft³
Re3.32 Ω
Sd85.5 in²
Xmax0.35″
Vd30.3 in³ calc.
Mms141 g calc.
BL16.3 T·m calc.
EBP90 — sealed or ported calc.
Sensitivity, 1 W / 1 m90.4 dB calc.

General

Size13″
Voice coils4 Ω
RMS power400 W

Mounting dimensions

Ø13 3/16″cutout ≈ Ø11 7/8″mounting depth 5 7/8″magnet Ø≈ 7 3/4″
Cutout diameter≈ 11 7/8″
Mounting depth5 7/8″
Overall diameter13 3/16″

“≈” 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 Focal 13″ models