American Bass XD-844

8″ subwoofer · dual 4 Ω · 450 W RMS

Fs 49.8 HzQts 0.61Vas 0.23 ft³Xmax 0.41″

Recommended box

For a sedan, one sub, 450 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 volume0.32 ft³ (9 L)
Qtc0.80
Fc65 Hz
F3 (−3 dB, no cabin gain)60 Hz
Example box (outside)10 5/8″ × 10 5/8″ × 8 5/8″
Open sealed box in designer

Ported

Net volume0.85 ft³ (24 L)
Tuning (Fb)35 Hz
Portround port Ø3″, 15 15/16″ long
Port velocity at 450 W165 ft/s
F3 (−3 dB, no cabin gain)31 Hz
Example box (outside)20 5/16″ × 15 3/4″ × 7 11/16″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs49.8 Hz
Qts0.61
Qes0.694
Qms5.4
Vas0.23 ft³
Re (one coil)≈ 3.4 Ω
Sd31.2 in²
Xmax0.41″
Vd12.8 in³ calc.
Mms92 g calc.
BL11.8 T·m calc.
EBP72 — sealed or ported calc.
Sensitivity, 1 W / 1 m82.6 dB calc.

General

Size8″
Voice coilsdual 4 Ω
RMS power450 W

Mounting dimensions

Ø≈ 8 11/16″cutout Ø7 1/2″mounting depth 5 3/16″magnet Ø≈ 4 7/8″
Cutout diameter7 1/2″
Mounting depth5 3/16″

Cone area (Sd) calculated from Fs, Vas and Mms: 31.2 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 American Bass 8″ models