Ground Zero GZHW 18XSPL-D1 (2x1 Ohm)

18″ subwoofer · dual 1 Ω

Fs 34.3 HzQts 0.38Vas 2.66 ft³Xmax 0.89″

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 volume1.94 ft³ (55 L)
Qtc0.59
Fc53 Hz
F3 (−3 dB, no cabin gain)68 Hz
Example box (outside)20 1/16″ × 20 1/16″ × 12 7/16″
Open sealed box in designer

Ported

Net volume3.46 ft³ (98 L)
Tuning (Fb)33 Hz
Portslot 1 9/16 × 19 7/16″, 17 1/8″ long
Port velocity at 300 W58 ft/s
F3 (−3 dB, no cabin gain)32 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 13 11/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs34.3 Hz
Qts0.38
Qes0.407
Qms6
Vas2.66 ft³
Re (one coil)≈ 0.85 Ω
Sd≈ 180.6 in²
Xmax0.89″
EBP84 — sealed or ported calc.
Sensitivity, 1 W / 1 m90.7 dB calc.

General

Size18″
Voice coilsdual 1 Ω
RMS power—

Mounting dimensions

Ø≈ 17 15/16″cutout Ø16 3/4″mounting depth 10 1/16″magnet Ø≈ 10 7/8″
Cutout diameter16 3/4″
Mounting depth10 1/16″

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 18″ models