URAL Ultimatum 12 (1+1)

12″ subwoofer · dual 1 Ω · 4,000 W RMS

Fs 29.7 HzQts 0.43Vas 0.82 ft³Xmax 1.57″

Recommended box

For a sedan, one sub, 4,000 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 volume0.97 ft³ (27.5 L)
Qtc0.58
Fc40 Hz
F3 (−3 dB, no cabin gain)53 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 12 7/8″
Open sealed box in designer

Ported

Net volume1.41 ft³ (40 L)
Tuning (Fb)27 Hz
Portround port Ø2 1/2″, 11 1/8″ long
Port velocity at 4,000 W730 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)18 1/8″ × 15 3/4″ × 12 13/16″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs29.7 Hz
Qts0.43
Qes0.48
Qms3.8
Vas0.82 ft³
Re (one coil)≈ 0.85 Ω
Sd73.2 in²
Xmax1.57″
Vd115.3 in³ calc.
Mms393 g calc.
BL11.4 T·m calc.
EBP62 — sealed or ported calc.
Sensitivity, 1 W / 1 m83 dB calc.

General

Size12″
Voice coilsdual 1 Ω
RMS power4,000 W

Mounting dimensions

Ø12 1/2″cutout Ø11 1/16″mounting depth 10 3/8″magnet Ø9 13/16″
Cutout diameter11 1/16″
Mounting depth10 3/8″
Overall diameter12 1/2″
Magnet diameter9 13/16″

Cone area (Sd) calculated from Fs, Vas and Mms: 73.2 in².

“≈” 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