JBL P1222

12″ subwoofer · dual 2 Ω · 400 W RMS

Fs 28.6 HzQts 0.55Vas 1.53 ft³Xmax 0.55″

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 volume1.34 ft³ (38 L)
Qtc0.80
Fc42 Hz
F3 (−3 dB, no cabin gain)39 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 16 13/16″

The volume and tuning are the recommendation, but the port doesn’t fit this example box. Size the box and port in the designer.

Open sealed box in designer

Ported

Net volume3.39 ft³ (96 L)
Tuning (Fb)25 Hz
Portslot 1 15/16 × 14 5/16″, 31 3/16″ long
Port velocity at 400 W63 ft/s
F3 (−3 dB, no cabin gain)22 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 18 1/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs28.6 Hz
Qts0.55
Qes0.58
Qms9.04
Vas1.53 ft³
Re (one coil)2 Ω
Sd87.1 in²
Xmax0.55″
Vd48 in³ calc.
Mms320 g calc.
BL14.1 T·m calc.
EBP49 — suits sealed calc.
Sensitivity, 1 W / 1 m84.4 dB calc.

General

Size12″
Voice coilsdual 2 Ω
RMS power400 W

Mounting dimensions

Ø14 5/8″cutout Ø11 1/16″mounting depth 6 3/4″magnet Ø≈ 7 3/16″
Cutout diameter11 1/16″
Mounting depth6 3/4″
Overall diameter14 5/8″

“≈” 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