JBL 1200GTi

12″ subwoofer · 4 Ω · 600 W RMS

Fs 37 HzQts 0.47Vas 2.00 ft³Xmax 0.22″

Recommended box

For a sedan, one sub, 600 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 volume1.06 ft³ (30 L)
Qtc0.80
Fc63 Hz
F3 (−3 dB, no cabin gain)60 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 13 13/16″
Open sealed box in designer

Ported

Net volume3.28 ft³ (93 L)
Tuning (Fb)34 Hz
Portslot 2 3/4 × 14 5/16″, 22 5/8″ long
Port velocity at 600 W61 ft/s
F3 (−3 dB, no cabin gain)31 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 17 7/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs37 Hz
Qts0.47
Qes0.52
Qms4.89
Vas2.00 ft³
Re2.5 Ω
Sd84.9 in²
Xmax0.22″
Vd18.4 in³ calc.
Mms139 g calc.
BL12.5 T·m calc.
EBP71 — sealed or ported calc.
Sensitivity, 1 W / 1 m89.4 dB calc.

General

Size12″
Voice coils4 Ω
RMS power600 W

Mounting dimensions

Ø12 3/16″cutout Ø11 3/16″mounting depth 4 1/4″magnet Ø≈ 7 1/4″
Cutout diameter11 3/16″
Mounting depth4 1/4″
Overall diameter12 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 JBL 12″ models