JL Audio 12W1-4

12″ subwoofer · 4 Ω · 125 W RMS

Fs 22.3 HzQts 0.49Vas 6.22 ft³Xmax 0.31″

Recommended box

For a sedan, one sub, 125 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 volume1.80 ft³ (51 L)
Qtc1.03
Fc47 Hz
F3 (−3 dB, no cabin gain)39 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 1/16″
Open sealed box in designer

Ported

Net volume3.04 ft³ (86 L)
Tuning (Fb)34 Hz
Portslot 1 9/16 × 14 5/16″, 13 1/4″ long
Port velocity at 125 W39 ft/s
F3 (−3 dB, no cabin gain)32 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 14 15/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs22.3 Hz
Qts0.49
Qes0.518
Qms8.26
Vas6.22 ft³
Re3.65 Ω
Sd78.5 in²
Xmax0.31″
Vd24.7 in³ calc.
Mms105 g calc.
BL10.2 T·m calc.
EBP43 — suits sealed calc.
Sensitivity, 1 W / 1 m87.8 dB calc.

General

Size12″
Voice coils4 Ω
RMS power125 W

Mounting dimensions

Ø12 3/8″cutout Ø11″mounting depth 5 1/4″magnet Ø≈ 7 1/8″
Cutout diameter11″
Mounting depth5 1/4″
Overall diameter12 3/8″

“≈” 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 JL Audio 12″ models