URAL AS-C12.2 (4+4)

12″ subwoofer · dual 4 Ω · 400 W RMS

Fs 33.1 HzQts 0.65Vas 1.84 ft³Xmax 1.26″

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 volume1.73 ft³ (49 L)
Qtc0.93
Fc48 Hz
F3 (−3 dB, no cabin gain)40 Hz
Example box (outside)14 9/16″ × 14 9/16″ × 19 3/4″
Open sealed box in designer

Ported

Net volume2.93 ft³ (83 L)
Tuning (Fb)33 Hz
Portslot 1 15/16 × 14 5/16″, 19 1/4″ long
Port velocity at 400 W61 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 15 3/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs33.1 Hz
Qts0.65
Qes0.729
Qms6
Vas1.84 ft³
Re (one coil)≈ 3.4 Ω
Sd≈ 76 in²
Xmax1.26″
EBP45 — suits sealed calc.
Sensitivity, 1 W / 1 m86.1 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power400 W

Mounting dimensions

Ø≈ 12 3/8″cutout Ø11 1/4″mounting depth 6 9/16″magnet Ø≈ 7 5/16″
Cutout diameter11 1/4″
Mounting depth6 9/16″

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 URAL 12″ models