Dayton Audio UMII8-22

8″ subwoofer · dual 2 Ω · 400 W RMS

Fs 46 HzQts 0.75Vas 0.30 ft³Xmax 0.71″

Recommended box

For a sedan, one sub, 400 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 volume0.60 ft³ (17 L)
Qtc0.92
Fc56 Hz
F3 (−3 dB, no cabin gain)48 Hz
Example box (outside)10 5/8″ × 10 5/8″ × 14 3/8″
Open sealed box in designer

Ported

Net volume1.20 ft³ (34 L)
Tuning (Fb)33 Hz
Port2 round ports Ø2 1/2″, 18 9/16″ long
Port velocity at 400 W119 ft/s
F3 (−3 dB, no cabin gain)28 Hz
Example box (outside)26 7/16″ × 15 3/4″ × 8 1/16″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs46 Hz
Qts0.75
Qes0.99
Qms3.1
Vas0.30 ft³
Re (one coil)1.95 Ω
Sd31 in²
Xmax0.71″
Vd22 in³ calc.
Mms81 g calc.
BL6.8 T·m calc.
EBP46 — suits sealed calc.
Sensitivity, 1 W / 1 m81.2 dB calc.

General

Size8″
Voice coilsdual 2 Ω
RMS power400 W

Mounting dimensions

Ø8 7/16″cutout Ø7 5/16″mounting depth 5 11/16″magnet Ø≈ 4 3/4″
Cutout diameter7 5/16″
Mounting depth5 11/16″
Overall diameter8 7/16″

“≈” 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 8″ models