JBL Selenium 18SWT3000

18″ subwoofer · 4 Ω · 1,500 W RMS

Fs 41 HzQts 0.54Vas 4.46 ft³Xmax 0.42″

Recommended box

For a sedan, one sub, 1,500 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 volume3.81 ft³ (108 L)
Qtc0.80
Fc60 Hz
F3 (−3 dB, no cabin gain)57 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 13 3/4″
Open sealed box in designer

Ported

Net volume7.17 ft³ (203 L)
Tuning (Fb)39 Hz
Portslot 4 15/16 × 19 1/16″, 15″ long
Port velocity at 1,500 W64 ft/s
F3 (−3 dB, no cabin gain)35 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 26 9/16″
Open ported box in designer
2030405060801001502007278849096102HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs41 Hz
Qts0.54
Qes0.57
Qms11.51
Vas4.46 ft³
Re3.19 Ω
Sd185.1 in²
Xmax0.42″
Vd77.2 in³ calc.
Mms241 g calc.
BL18.6 T·m calc.
EBP72 — sealed or ported calc.
Sensitivity, 1 W / 1 m93.8 dB calc.

General

Size18″
Voice coils4 Ω
RMS power1,500 W

Mounting dimensions

Ø≈ 17 11/16″cutout ≈ Ø16 9/16″mounting depth ≈ 8 1/4″magnet Ø≈ 10 3/4″
Cutout diameter≈ 16 9/16″
Mounting depth≈ 8 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 JBL Selenium 18″ models