JBL S3-1224 / Stadium 1224 (SSI 4 ohm)

12″ subwoofer · 4 Ω · 500 W RMS

Fs 29.1 HzQts 0.47Vas 1.86 ft³Xmax 0.47″

Recommended box

For a sedan, one sub, 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 volume0.99 ft³ (28 L)
Qtc0.80
Fc49 Hz
F3 (−3 dB, no cabin gain)47 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 13 1/16″
Open sealed box in designer

Ported

Net volume3.18 ft³ (90 L)
Tuning (Fb)27 Hz
Portslot 1 15/16 × 14 5/16″, 28 3/16″ long
Port velocity at 500 W64 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 16 15/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs29.1 Hz
Qts0.47
Qes0.58
Qms2.56
Vas1.86 ft³
Re4.07 Ω
Sd82.3 in²
Xmax0.47″
Vd38.9 in³ calc.
Mms228 g calc.
BL17.1 T·m calc.
EBP50 — sealed or ported calc.
Sensitivity, 1 W / 1 m85.5 dB calc.

General

Size12″
Voice coils4 Ω
RMS power500 W

Mounting dimensions

Ø12 3/4″cutout Ø11 1/8″mounting depth 6 15/16″magnet Ø≈ 7 3/16″
Cutout diameter11 1/8″
Mounting depth6 15/16″
Overall diameter12 3/4″

“≈” 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 12″ models