Ground Zero GZPW 18SPL-EXTREME (2x1 Ohm)
18″ subwoofer · dual 1 Ω
Fs 41 HzQts 0.34Vas 2.47 ft³Xmax 0.69″
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 volume | 2.12 ft³ (60 L) |
|---|---|
| Qtc | 0.50 |
| Fc | 60 Hz |
| F3 (−3 dB, no cabin gain) | 96 Hz |
| Example box (outside) | 19 11/16″ × 19 11/16″ × 13 7/8″ |
Ported
| Net volume | 3.46 ft³ (98 L) |
|---|---|
| Tuning (Fb) | 38 Hz |
| Port | round port Ø5″, 6 13/16″ long |
| Port velocity at 300 W | 100 ft/s |
| F3 (−3 dB, no cabin gain) | 37 Hz |
| Example box (outside) | 29″ × 20 1/2″ × 14″ |
Thiele/Small parameters
| Fs | 41 Hz |
|---|---|
| Qts | 0.34 |
| Qes | 0.36 |
| Qms | 6 |
| Vas | 2.47 ft³ |
| Re (one coil) | ≈ 0.85 Ω |
| Sd | ≈ 180.6 in² |
| Xmax | 0.69″ |
| EBP | 114 — suits ported calc. |
| Sensitivity, 1 W / 1 m | 93.3 dB calc. |
General
| Size | 18″ |
|---|---|
| Voice coils | dual 1 Ω |
| RMS power | — |
Mounting dimensions
| Cutout diameter | 16 9/16″ |
|---|---|
| Mounting depth | 11 7/16″ |
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
- Ground Zero GZHW 18XSPL-D1 (2x1 Ohm) 18″ · dual 1 Ω
- Ground Zero GZNW 18XSPL (2x1 Ohm) 18″ · dual 1 Ω
- Ground Zero GZPW 18SPL (2x1 Ohm) 18″ · dual 1 Ω