URAL Patriot 18 (2+2)

18″ subwoofer · dual 2 Ω · 2,500 W RMS

Fs 26.1 HzQts 0.33Vas 5.37 ft³Xmax 1.26″

Recommended box

For a sedan, one sub, 2,500 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 volume1.62 ft³ (46 L)
Qtc0.68
Fc54 Hz
F3 (−3 dB, no cabin gain)60 Hz
Example box (outside)19 11/16″ × 19 11/16″ × 11 5/16″
Open sealed box in designer

Ported

Net volume3.43 ft³ (97 L)
Tuning (Fb)32 Hz
Portslot 3 3/4 × 19 1/16″, 47 5/16″ long
Port velocity at 2,500 W63 ft/s
F3 (−3 dB, no cabin gain)32 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 19 5/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs26.1 Hz
Qts0.33
Qes0.35
Qms4.62
Vas5.37 ft³
Re (one coil)≈ 1.7 Ω
Sd179.7 in²
Xmax1.26″
Vd226.4 in³ calc.
Mms465 g calc.
BL19.2 T·m calc.
EBP75 — sealed or ported calc.
Sensitivity, 1 W / 1 m90.9 dB calc.

General

Size18″
Voice coilsdual 2 Ω
RMS power2,500 W

Mounting dimensions

Ø≈ 17 11/16″cutout ≈ Ø16 9/16″mounting depth ≈ 8 1/4″magnet Ø≈ 10 3/4″
Cutout diameter≈ 16 9/16″
Mounting depth≈ 8 1/4″

Cone area (Sd) calculated from Fs, Vas and Mms: 179.7 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 18″ models