Kicx STQ 300NEW (4+4)

12″ subwoofer · dual 4 Ω · 400 W RMS

Fs 30 HzQts 0.73Vas 3.25 ft³Xmax 0.39″

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 volume1.80 ft³ (51 L)
Qtc1.23
Fc50 Hz
F3 (−3 dB, no cabin gain)38 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 1/16″
Open sealed box in designer

Ported

Net volume3.07 ft³ (87 L)
Tuning (Fb)38 Hz
Portslot 1 3/4 × 14 5/16″, 11 1/8″ long
Port velocity at 400 W65 ft/s
F3 (−3 dB, no cabin gain)33 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 15″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs30 Hz
Qts0.73
Qes0.82
Qms7.02
Vas3.25 ft³
Re (one coil)3.7 Ω
Sd79.1 in²
Xmax0.39″
Vd31.1 in³ calc.
Mms113 g calc.
BL9.8 T·m calc.
EBP37 — suits sealed calc.
Sensitivity, 1 W / 1 m86.8 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power400 W

Mounting dimensions

Ø≈ 12 5/16″cutout ≈ Ø11 1/8″mounting depth 6 1/8″magnet Ø5 1/2″
Cutout diameter≈ 11 1/8″
Mounting depth6 1/8″
Magnet diameter5 1/2″

“≈” 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 Kicx 12″ models