Kicx QS-380 (4+4)

15″ subwoofer · dual 4 Ω · 900 W RMS

Fs 25 HzQts 1.18Vas 3.67 ft³Xmax 0.56″

Recommended box

For a sedan, one sub, 900 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 volume2.83 ft³ (80 L)
Qtc1.79
Fc38 Hz
F3 (−3 dB, no cabin gain)27 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 11 3/4″
Open sealed box in designer

Ported

Net volume4.80 ft³ (136 L)
Tuning (Fb)33 Hz
Portslot 2 3/4 × 16 11/16″, 17 15/16″ long
Port velocity at 900 W63 ft/s
F3 (−3 dB, no cabin gain)26 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 20 1/2″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs25 Hz
Qts1.18
Qes1.49
Qms5.62
Vas3.67 ft³
Re (one coil)≈ 3.4 Ω
Sd≈ 124 in²
Xmax0.56″
EBP17 — suits sealed calc.
Sensitivity, 1 W / 1 m82.4 dB calc.

General

Size15″
Voice coilsdual 4 Ω
RMS power900 W

Mounting dimensions

Ø≈ 15 3/16″cutout ≈ Ø14″mounting depth 8 13/16″magnet Ø≈ 9 1/16″
Cutout diameter≈ 14″
Mounting depth8 13/16″

“≈” 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 Kicx 15″ models