Ground Zero GZHW 20X (2x2 Ohm)

8″ subwoofer · dual 2 Ω · 400 W RMS

Fs 36 HzQts 0.36Vas 0.29 ft³Xmax 0.45″

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 volume0.28 ft³ (8 L)
Qtc0.51
Fc51 Hz
F3 (−3 dB, no cabin gain)80 Hz
Example box (outside)10 5/8″ × 10 5/8″ × 7 7/8″
Open sealed box in designer

Ported

Net volume0.60 ft³ (17 L)
Tuning (Fb)29 Hz
Portslot 1 15/16 × 14 5/16″, 144 15/16″ long
Port velocity at 400 W30 ft/s
F3 (−3 dB, no cabin gain)28 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 14 1/2″

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
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs36 Hz
Qts0.36
Qes0.39
Qms4.25
Vas0.29 ft³
Re (one coil)1.75 Ω
Sd31.8 in²
Xmax0.45″
Vd14.4 in³ calc.
Mms140 g calc.
BL11.9 T·m calc.
EBP92 — sealed or ported calc.
Sensitivity, 1 W / 1 m82 dB calc.

General

Size8″
Voice coilsdual 2 Ω
RMS power400 W

Mounting dimensions

Ø≈ 8 9/16″cutout Ø7 3/8″mounting depth 4 3/4″magnet Ø6 3/16″
Cutout diameter7 3/8″
Mounting depth4 3/4″
Magnet diameter6 3/16″

Cone area (Sd) calculated from Fs, Vas and Mms: 31.8 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 Ground Zero 8″ models