Pride UFO.5 18 D0.7

18″ subwoofer · dual 0.7 Ω · 10,000 W RMS

Fs 19.8 HzQts 0.14Vas 5.40 ft³Xmax 1.67″
The published specs don’t add up:

Recommended box

For a sedan, one sub, 10,000 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 volume2.52 ft³ (71.5 L)
Qtc0.25
Fc35 Hz
F3 (−3 dB, no cabin gain)134 Hz
Example box (outside)20 1/16″ × 20 1/16″ × 15 3/8″
Open sealed box in designer

Ported

Net volume4.06 ft³ (115 L)
Tuning (Fb)25 Hz
Portslot 3 3/8 × 19 7/16″, 61 7/8″ long
Port velocity at 10,000 W164 ft/s
F3 (−3 dB, no cabin gain)126 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 22 5/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs19.8 Hz
Qts0.14
Qes0.143
Qms6
Vas5.40 ft³
Re (one coil)0.76 Ω
Sd211.6 in²
Xmax1.67″
Vd354 in³ calc.
Mms1,111 g calc.
BL27.1 T·m calc.
EBP139 — suits ported calc.
Sensitivity, 1 W / 1 m91.2 dB calc.

General

Size18″
Voice coilsdual 0.7 Ω
RMS power10,000 W

Mounting dimensions

Ø≈ 18 1/8″cutout Ø16 15/16″mounting depth 12 15/16″magnet Ø≈ 11″
Cutout diameter16 15/16″
Mounting depth12 15/16″

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

Judging by its value, the published Re is for both coils in series — converted to per coil.

“≈” 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 Pride 18″ models