Dayton Audio UMII18-22

18″ subwoofer · dual 2 Ω · 1,200 W RMS

Fs 22 HzQts 0.53Vas 8.77 ft³Xmax 1.10″

Recommended box

For a sedan, one sub, 1,200 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 volume4.17 ft³ (118 L)
Qtc0.93
Fc39 Hz
F3 (−3 dB, no cabin gain)33 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 14 9/16″
Open sealed box in designer

Ported

Net volume7.10 ft³ (201 L)
Tuning (Fb)28 Hz
Portslot 2 15/16 × 19 7/16″, 21 5/16″ long
Port velocity at 1,200 W64 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 25 3/4″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs22 Hz
Qts0.53
Qes0.67
Qms2.53
Vas8.77 ft³
Re (one coil)2.1 Ω
Sd183.5 in²
Xmax1.10″
Vd202.3 in³ calc.
Mms419 g calc.
BL13.5 T·m calc.
EBP33 — suits sealed calc.
Sensitivity, 1 W / 1 m88 dB calc.

General

Size18″
Voice coilsdual 2 Ω
RMS power1,200 W

Mounting dimensions

Ø18 1/2″cutout Ø16 13/16″mounting depth 9″magnet Ø≈ 10 15/16″
Cutout diameter16 13/16″
Mounting depth9″
Overall diameter18 1/2″

“≈” 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 Dayton Audio 18″ models