Kenwood KFC-XW1241

12″ subwoofer · 4 Ω · 300 W RMS

Fs 24.4 HzQts 0.48Vas 3.67 ft³Xmax 0.23″

Recommended box

For a sedan, one sub, 300 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 volume1.73 ft³ (49 L)
Qtc0.85
Fc43 Hz
F3 (−3 dB, no cabin gain)39 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 8 3/4″
Open sealed box in designer

Ported

Net volume2.93 ft³ (83 L)
Tuning (Fb)31 Hz
Portslot 1 9/16 × 14 5/16″, 17 1/2″ long
Port velocity at 300 W60 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 14 13/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs24.4 Hz
Qts0.48
Qes0.525
Qms6
Vas3.67 ft³
Re≈ 3.4 Ω
Sd≈ 76 in²
Xmax0.23″
EBP46 — suits sealed calc.
Sensitivity, 1 W / 1 m86.6 dB calc.

General

Size12″
Voice coils4 Ω
RMS power300 W

Mounting dimensions

Ø≈ 12 5/16″cutout ≈ Ø11 1/8″mounting depth 5 3/8″magnet Ø≈ 7 3/16″
Cutout diameter≈ 11 1/8″
Mounting depth5 3/8″

Only Qts is published — Qms assumed to be 6 and Qes calculated (barely affects box design).

“≈” 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 Kenwood 12″ models