Ground Zero GZHW 8XSPL-D1 (2x1 Ohm)

8″ subwoofer · dual 1 Ω

Fs 42.5 HzQts 0.47Vas 0.13 ft³Xmax 0.79″

Recommended box

For a sedan, one sub, 300 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 volume0.41 ft³ (11.5 L)
Qtc0.54
Fc49 Hz
F3 (−3 dB, no cabin gain)69 Hz
Example box (outside)11 13/16″ × 11 13/16″ × 8 1/2″
Open sealed box in designer

Ported

Net volume0.64 ft³ (18 L)
Tuning (Fb)26 Hz
Portslot 1 15/16 × 14 5/16″, 171 1/8″ long
Port velocity at 300 W26 ft/s
F3 (−3 dB, no cabin gain)24 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 16 7/16″

The volume and tuning are the recommendation, but the port doesn’t fit this example box. Size the box and port in the designer.

Open ported box in designer
2030405060801001502005460667278HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs42.5 Hz
Qts0.47
Qes0.513
Qms6
Vas0.13 ft³
Re (one coil)≈ 0.85 Ω
Sd≈ 33.3 in²
Xmax0.79″
EBP83 — sealed or ported calc.
Sensitivity, 1 W / 1 m79.4 dB calc.

General

Size8″
Voice coilsdual 1 Ω
RMS power—

Mounting dimensions

Ø≈ 9 5/8″cutout Ø8 7/16″mounting depth 5 7/8″magnet Ø≈ 5 1/2″
Cutout diameter8 7/16″
Mounting depth5 7/8″

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

“≈” 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 Ground Zero 8″ models