Performance Optimized · Datasheet
Performance Optimized Wedge Sealed 8" Enclosure Ground Zero GZHW 20 · Single 8" Sealed enclosure
- Net volume
- 0.28 cu ft
- Max mounting depth
- 6.200 in available, 5.700 in required
- Cutout
- 7.360 in
- External dimensions
- 10.97 in W × 11.75 in at the seat face H × 12.07 in at the base D
- Front baffle
- 1.5 in, double baffle
- Best For: Ground Zero GZHW 20 Trunk-Fit Builds
- Net Volume: 0.28 cu ft (0.35 cu ft Gross)
- Alignment: Qtc 0.707, fc 50.0 Hz, F3 50.0 Hz
- Driver Match: Ground Zero GZHW 20 (D1 or D2)
- Construction: Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | Threaded Insert Kit included
Spec of record
Technical specifications
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Wedge |
| Compatible Driver | Ground Zero GZHW 20, D1 or D2, quantity 1. Direct fit |
| Configuration | Single 8 inch, single chamber sealed wedge |
| Mounting Position | Trunk or cargo area, tall face against the rear seat back |
| Firing Direction | Rearward into the trunk. Not a down fire design, no feet included |
| External Width | 10.97 in |
| External Height | 11.75 in at the seat face |
| External Depth | 12.07 in at the base, tapering to 7.79 in at the top |
| Internal Volume, Gross | 0.35 cu ft |
| Internal Volume, Net Acoustic | 0.28 cu ft |
| Alignment | Qtc 0.707, fc 50.0 Hz, F3 50.0 Hz anechoic |
| Driver Cutout | 7.360 in |
| Driver Mounting Depth | 6.200 in available, 5.700 in required |
| Frame Outer Diameter | 8.270 in, as published by Ground Zero |
| Driver Displacement | 0.057 cu ft, ESTIMATED, Ground Zero publishes none |
| Cone Area (estimated) | 214.0 cm2, ESTIMATED from the published frame and cutout diameters; Ground Zero publish no Sd |
| Power Handling | 700 watts RMS |
| Impedance | D1: 2 ohms in series or 0.5 ohm in parallel; D2: 4 ohms in series or 1 ohm in parallel |
| Xmax | 20 mm one way |
| Material | Langboard Elite MDF |
| Construction | CNC cut, V-groove and dado joinery |
| Panel Thickness | 0.75 in |
| Front Baffle | 1.5 in, double baffle |
| Internal Bracing | Internal brace |
| Driver Mounting | Threaded insert kit included, NOT pre-installed: Ground Zero publish no mounting hole locations |
| Terminal Cups | One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC |
| Damping | Light polyfill wall lining, does not alter acoustic volume |
| Carpet | Plush black |
| Weight | 13.6 lb |
| Warranty | 1 Year Limited |
| Built In | Tullahoma, Tennessee |
From the shop floor
Installer's take
0.28 cubic feet net, the Butterworth volume for this driver computed from Ground Zero's published Fs, Qts and Vas for the D1 coil. In it the GZHW 20 / GZHW 20XSPL lands at Qtc 0.707, maximally flat, the reference musical alignment, with system resonance at 50.0 Hz. Half power lands at 50.0 Hz anechoic, before any cabin gain.
Ground Zero publishes no cone area and no driver displacement for this woofer, and no bolt circle either. The 214.0 square centimetre cone area behind this alignment is estimated from the frame and cutout diameters they do publish, and the displacement is estimated the same way. Both are marked estimated wherever they appear. Ground Zero publishes Fs, Qts, Qes, Qms and Vas, and those figures are theirs.
Ground Zero publishes no mounting hole locations, so the inserts are not in the baffle when the box arrives. The insert kit is in the box: set them where the woofer's own holes fall, with the drill bit and screws in the kit, and lay the gasket tape before the woofer goes down.
Ground Zero sells the GZHW 20 / GZHW 20XSPL in D1 and D2: the D1 is two 1 ohm coils, 2 ohms in series or 0.5 ohm in parallel; the D2 is two 2 ohm coils, 4 ohms in series or 1 ohm in parallel. Ground Zero prints a separate Thiele-Small column for each coil in the owner's manual. This cabinet is solved on the D1 column. In the same 0.28 cubic feet the D2 column lands at Qtc 0.782 with F3 at 48.1 Hz. The cutout, mounting depth and frame are the same for every coil, so it fits either. A parallel load at or under 1 ohm needs an amplifier rated for it.
Measure the base depth. This cabinet is 12.07 inches deep at the trunk floor, 7.79 at the top, and 10.97 wide. It is deeper at the base than it is tall, because the GZHW 20 / GZHW 20XSPL carries a 5.700 in motor and the cabinet has to clear it.
Before you order
Questions
Will this enclosure fit both coil versions of the GZHW 20 / GZHW 20XSPL?
Yes. Ground Zero sells the GZHW 20 / GZHW 20XSPL in D1 and D2. Ground Zero prints a separate Thiele-Small column for each coil in the owner's manual. This cabinet is solved on the D1 column. In the same 0.28 cubic feet the D2 column lands at Qtc 0.782 with F3 at 48.1 Hz. The cutout, mounting depth and frame are the same for every coil, so it fits either. The cutout is 7.360 in and the mounting depth allowance is 6.200 in.
Why 0.28 cubic feet net?
0.28 cubic feet net, the Butterworth volume for this driver computed from Ground Zero's published Fs, Qts and Vas for the D1 coil. In it the GZHW 20 / GZHW 20XSPL lands at Qtc 0.707, maximally flat, the reference musical alignment, with system resonance at 50.0 Hz. The box is 0.35 cu ft gross before the driver's displacement of 0.057 cu ft, which is an estimate: Ground Zero publish no displacement figure.
What amplifier power should I run, and what impedance?
Ground Zero rate the GZHW 20 / GZHW 20XSPL at 700 watts RMS. Ground Zero sells the GZHW 20 / GZHW 20XSPL in D1 and D2: the D1 is two 1 ohm coils, 2 ohms in series or 0.5 ohm in parallel; the D2 is two 2 ohm coils, 4 ohms in series or 1 ohm in parallel. Ground Zero prints a separate Thiele-Small column for each coil in the owner's manual. This cabinet is solved on the D1 column. In the same 0.28 cubic feet the D2 column lands at Qtc 0.782 with F3 at 48.1 Hz. The cutout, mounting depth and frame are the same for every coil, so it fits either. A parallel load at or under 1 ohm needs an amplifier rated for it. Aim for roughly 489 to 700 watts at the impedance you wire.
How does a wedge enclosure improve the sound in a trunk installation?
The angled seat-side face matches the roughly 20 degree lean of a factory rear seat, so the cabinet sits flat against it instead of leaving a wasted triangle. The vertical trunk-lid-side face carries the driver, firing rearward into the trunk cavity.
Where does the cone area figure come from?
Ground Zero publishes no cone area and no driver displacement for this woofer, and no bolt circle either. The 214.0 square centimetre cone area behind this alignment is estimated from the frame and cutout diameters they do publish, and the displacement is estimated the same way. Both are marked estimated wherever they appear. Ground Zero publishes Fs, Qts, Qes, Qms and Vas, and those figures are theirs.
What is the expected low-frequency extension?
Half power lands at 50.0 Hz anechoic, before any cabin gain. Qtc is 0.707. These figures exclude cabin gain, which in most vehicles adds real output below 40 Hz. Ground Zero publish the GZHW 20 / GZHW 20XSPL's free-air resonance at 38.90 Hz for the D1 coil.
Do I need to add polyfill or damping?
No. Polyfill is already installed as a light wall lining and the quantity is chosen so it does not change the acoustic volume. Do not add more.
Is the driver included, and are the threaded inserts installed?
No driver: this is an enclosure only. You receive the cabinet finished in plush black carpet, one side-mounted pre-wired terminal cup and the polyfill lining installed. Ground Zero publishes no mounting hole locations for this driver, so the threaded inserts are not pressed before it ships. The threaded insert kit comes in the box instead: inserts sized to the woofer, the correct drill bit, allen-head screws, an allen key and woofer gasket tape. You set them when the woofer goes in.
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