URAL Molot 12 (2+2)

12″ subwoofer · dual 2 Ω · 300 W RMS

Fs 34.5 HzQts 0.88Vas 1.52 ft³Xmax 0.28″

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 volume1.80 ft³ (51 L)
Qtc1.20
Fc47 Hz
F3 (−3 dB, no cabin gain)36 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 1/16″
Open sealed box in designer

Ported

Net volume3.04 ft³ (86 L)
Tuning (Fb)34 Hz
Portslot 1 9/16 × 14 5/16″, 13 1/4″ long
Port velocity at 300 W65 ft/s
F3 (−3 dB, no cabin gain)28 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 14 15/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs34.5 Hz
Qts0.88
Qes1.01
Qms6.96
Vas1.52 ft³
Re (one coil)≈ 1.7 Ω
Sd78.7 in²
Xmax0.28″
Vd21.7 in³ calc.
Mms180 g calc.
BL8.1 T·m calc.
EBP34 — suits sealed calc.
Sensitivity, 1 W / 1 m84.4 dB calc.

General

Size12″
Voice coilsdual 2 Ω
RMS power300 W

Mounting dimensions

Ø12 11/16″cutout Ø11 1/4″mounting depth 5 1/4″magnet Ø6 3/4″
Cutout diameter11 1/4″
Mounting depth5 1/4″
Overall diameter12 11/16″
Magnet diameter6 3/4″

Cone area (Sd) calculated from Fs, Vas and Mms: 78.7 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