Ground Zero GZIW 200X-II (4 Ohm)

8″ subwoofer · 4 Ω · 150 W RMS

Fs 39.9 HzQts 0.52Vas 0.60 ft³Xmax 0.35″

Recommended box

For a sedan, one sub, 150 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 volume0.42 ft³ (12 L)
Qtc0.80
Fc62 Hz
F3 (−3 dB, no cabin gain)58 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 11 5/8″
Open sealed box in designer

Ported

Net volume1.24 ft³ (35 L)
Tuning (Fb)34 Hz
Portslot 1 9/16 × 14 5/16″, 38 5/16″ long
Port velocity at 150 W34 ft/s
F3 (−3 dB, no cabin gain)31 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 1/4″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs39.9 Hz
Qts0.52
Qes0.56
Qms6.73
Vas0.60 ft³
Re3.3 Ω
Sd31.9 in²
Xmax0.35″
Vd11.3 in³ calc.
Mms56 g calc.
BL9.1 T·m calc.
EBP71 — sealed or ported calc.
Sensitivity, 1 W / 1 m84.9 dB calc.

General

Size8″
Voice coils4 Ω
RMS power150 W

Mounting dimensions

Ø8 5/16″cutout Ø7 3/16″mounting depth 4″magnet Ø≈ 4 11/16″
Cutout diameter7 3/16″
Mounting depth4″
Overall diameter8 5/16″

Cone area (Sd) calculated from Fs, Vas and Mms: 31.9 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