Professional Series · Datasheet
Professional Series Ported 8" Enclosure Ground Zero GZRW 8XSPL · Single 8" Ported enclosure
- Net volume
- 1.32 Cubic Feet
- Tuning
- 32.5 Hz
- Max mounting depth
- 5.240 Inches (Ground Zero Spec)
- Cutout
- 7.170 Inches (Ground Zero Spec)
- External dimensions
- 30.00 Inches W × 14.00 Inches H × 12.50 Inches D
- Front baffle
- Three 3/4" MDF layers, 2.25" total | Woofer Flush-Mounted In The Outer Layer
- Alignment: 1.32 cu ft net vented at 32.5 Hz. F3 28.2 Hz anechoic, 3.82 dB passband ripple
- Driver: Ground Zero GZRW 8XSPL SVC or D1, 500 W RMS, 14.0 mm Xmax, 46.00 Hz Fs
- Build: Front-firing standard box, 2.25" three-layer baffle with the woofer flush-mounted in the outer layer, Ground Zero logo acrylic, dado joinery, 21.9 sq in front slot port beside the woofer with one bend along the back wall, port and excursion gated at 600 W
- Cabinet: 30.00" W x 14.00" H x 12.50" D, 50 lb, threaded insert kit included
Spec of record
Technical specifications
| Series | Proline X Professional |
|---|---|
| Driver-Specific Fitment | Ground Zero GZRW 8XSPL SVC or D1 (D1) |
| Enclosure Type | Ported | Front-Firing Standard Box |
| External Width | 30.00 Inches |
| External Height | 14.00 Inches |
| External Depth | 12.50 Inches |
| Internal Volume (Gross) | 1.96 Cubic Feet |
| Internal Volume (Net After Displacement) | 1.32 Cubic Feet |
| Port Type | Vertical Slot Beside The Woofer | Front Exit | One 90 Degree Bend Along The Back Wall |
| Port Geometry | 1.75 x 12.50 Inches, 21.9 Square Inches, 33.83 Inches Of Path |
| Port Area | 21.9 Square Inches |
| Port Tuning (Fb) | 32.5 Hz |
| Port Mouth | 1/2 In Roundover On All Four Edges, 37.1 Square Inches At The Face |
| Port Air Velocity | 20.1 m/s In The Channel, 11.8 m/s At The Mouth, At 600 W (17.0 m/s Chuff Threshold) |
| Design Power Basis | 600 W RMS (1.2 x The Driver Rating) For Port Velocity And Excursion |
| Predicted F3 | 28.2 Hz (Anechoic) |
| Passband Ripple | 3.82 dB (Anechoic) |
| Subsonic Filter | 26 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure |
| Driver Fs | 46.00 Hz |
| Driver Qts | 0.360 |
| Driver Qes / Qms | 0.380 / 8.710 |
| Driver Vas | 5.000 Liters / 0.177 Cubic Feet |
| Driver Sd | 214.0 Square Centimeters |
| Driver BL | 14.10 |
| Driver Re | 1.9 Ohm |
| Driver Xmax | 14mm (One-Way) |
| Driver Displacement | 0.05 Cubic Feet (Published by Ground Zero) |
| Driver Sensitivity | 84.0 dB |
| Driver Power Handling | 500 Watts RMS |
| Driver Overall Diameter | 8.482 Inches (Ground Zero Spec) |
| Mounting Depth Required | 5.240 Inches (Ground Zero Spec) |
| Cutout Diameter | 7.170 Inches (Ground Zero Spec) |
| Flush Mount Recess | 9.500 Inches In The Outer Layer |
| Material | Langboard Elite 3/4" MDF |
| Construction | ShopSabre CNC / Two Windowed Braces Front To Back Either Side Of The Woofer |
| Joinery | Dado Joinery (CNC-Cut), Flat Panels |
| Front Baffle Construction | Three 3/4" MDF layers, 2.25" total | Woofer Flush-Mounted In The Outer Layer |
| Baffle Layers | 3 |
| Acrylic | Glossy Black Ground Zero Logo Insert, Outer Layer, Standard |
| Mounting Hardware | Threaded Insert Kit Included: 8-12 Inserts, Drill Bit, 2.5 In Allen-Head Screws, Allen Key, Gasket Tape |
| Voice Coil Configuration | D1 |
| Terminal Cup | Proline X ABS/Carbon Fiber Composite | Back Panel, Terminal-Cup Side | 12g OFC Pre-Wired |
| Damping | None - Ships Dry. Polyfill Detunes A Ported Enclosure |
| Recommended Power | 350-500 Watts RMS (Ground Zero Rated: 500W RMS) |
| Carpet Finish | Plush Black |
| Weight | 50 lb |
| Shipping | UPS Ground Parcel, Included In The 48 States |
| Bundle Options | Enclosure Only (Bring Your Own Ground Zero GZRW 8XSPL) |
| Warranty | 2-Year Limited (Enclosure) |
| Manufactured | Tullahoma, Tennessee, USA |
Modelled response
Performance in this enclosure
01Is this driver right for a ported box?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
1.32 cu ft net against a 5.0 L Vas, vented at 32.5 Hz.
03Ported vs Sealed
No sealed comparison is shown for this driver.
04The watts that reach Xmax (in this enclosure)
Travel scales with the square root of power, so there is one wattage that puts the cone exactly on Ground Zero's published 14.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.
From the shop floor
Installer's take
I built this box on Ground Zero's own published Fs, Qts, and Vas for the GZRW 8XSPL: 46.00 Hz, 0.3600, and 5.00 litres. It lands at 1.320 cubic feet net, vented at 32.5 Hz, and the model gives back F3 at 28.2 Hz with 3.82 dB of ripple. Ground Zero publishes no vented number of their own for this driver, so there is nothing to check the curve against.
Ground Zero publishes no cone area for this driver. The 214.0 square centimetre Sd behind this alignment, the tuning, the port sizing, and the velocity math, is estimated rather than measured or stated by Ground Zero. Ground Zero also publishes no driver displacement; the 0.049 cubic foot figure I used is estimated too, and it only touches the gross volume number, not the tuning or the port.
Ground Zero calls its excursion spec Max. Excursion and never says what it is measured to. For the GZRW 8XSPL the manual gives a peak-to-peak figure, and I halved it to the 14.0 mm one-way number this box is built around. That halving is the reason this model gets a cabinet at all; most of the rest of the Ground Zero line states no basis for its excursion figure and stays off the bench.
Ground Zero publishes no mounting hole locations for this driver, so I am not pressing the threaded inserts before it ships. The insert kit rides loose in the box; set them at install once the driver is in hand.
The GZRW 8XSPL ships SVC or D1. Wire the SVC straight to your amplifier's rated impedance; wire the D1's two coils in series for 2 ohms or parallel for 0.5 ohm, and a sub-1-ohm parallel load needs an amplifier built for it.
Ground Zero publishes no mounting hole locations for the GZRW 8XSPL, so the inserts are not in the baffle when the box arrives. The insert kit is in the box: set the inserts where the woofer's own holes fall, with the drill bit and the 2.5 inch allen-head screws in the kit, and lay the gasket tape before the woofer goes down.
The Performance Optimized wedge is the smaller and cheaper box, and I try it first for every driver. The GZRW 8XSPL does not fit it, so this is the box.
It ships dry. Do not add polyfill to a ported box. Set your subsonic filter at 27 Hz.
Before you order
Questions
Why is this enclosure tuned to 32.5 Hz?
A 0.3600 Qts on 5.00 litres of Vas is a tight, low-compliance motor, and 32.5 Hz brings F3 to 28.2 Hz on 3.82 dB of ripple. At the driver's rated 500 W the port runs 11.8 metres per second through the mouth at 600 W, the reference point the velocity check is measured against. The 214.0 square centimetre Sd behind this solve is not a Ground Zero figure: Ground Zero publishes no cone area for the GZRW 8XSPL, so the number is estimated. Ground Zero also labels its 14.0 mm Xmax figure Max. Excursion without stating a basis; for this model the manual gives a peak-to-peak number, halved here to the one-way figure used in the math, which is the reason this model builds at all while other Ground Zero models with no stated basis are held. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz, and this tuning is where that sum comes out flattest across 25 to 60 Hz.
Why is this a Professional build and not a Performance Optimized box?
Every driver is run through the Performance Optimized wedge and down-fire before this chassis; the Professional box is where a driver lands when that smaller envelope, 30 inches wide and 18 inches deep with a triangular side port, cannot give it what it needs at its rated power. The GZRW 8XSPL did not clear the channel 28.5 m/s over 0.55 x core 33.8 gate there: the nearest wedge that fits is 30.0 by 9.12 by 13.40 inches with a 13.0 square inch port, and no tuning, width or depth inside that envelope passes. The slot on this box reaches 21.9 square inches. An under-ported box does not fail quietly. Air speed at the mouth rises with power; past the chuff line the flow turns turbulent and the port is audible on every note. The turbulence also chokes the port, so the box behaves as if it were tuned higher than it is, loses output near tuning, and lets the cone travel further below tuning than the design allows. This chassis is a full-size front-firing box on a 2.25 inch baffle built from three 3/4 inch layers with the woofer flush-mounted in the outer layer, a Ground Zero logo acrylic, and a port and excursion budget checked at 600 W. It carries a 2 year warranty against 1.
Threaded inserts or a kit?
Ground Zero does not publish the mounting hole locations for the GZRW 8XSPL, so we cannot install the threaded inserts before it ships. The threaded insert kit comes in the box instead: 8 to 12 inserts sized to the woofer, the correct drill bit, 2.5 inch allen-head screws, an allen key and woofer gasket tape. You set the inserts when you mount the woofer; one kit serves one woofer. A dual cabinet ships two kits.
Do I need a subsonic filter?
Yes, at 26 Hz, 24 dB per octave. Below tuning a vented box stops loading the cone and excursion runs away toward DC. With the filter in place this cabinet puts the Ground Zero GZRW 8XSPL at 64 percent of its usable travel at 600 W.
Would a sealed box be better for me?
Not one we can show you. We do not build a sealed enclosure for the Ground Zero GZRW 8XSPL and Ground Zero publish no sealed volume for it, so the Performance Graphs tab carries no ported-versus-sealed chart: the only sealed box left to plot would be this cabinet stuffed and sealed, which nobody would build, and a comparison against it would tell you nothing you could buy. What a vented box gives up is the region below tuning, where the cone unloads and the 26 Hz subsonic filter takes over; around 32.5 Hz the vent carries the load and cone travel drops to its minimum, which no sealed alignment can do.
How does the front port work?
It is a vertical slot beside the woofer, the full height of the cavity, 1.75 inches wide and 21.9 square inches. It runs 7.00 inches to the back wall and turns once along it for 21.33 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 20.1 metres per second at 600 W, 52 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 11.8 metres per second against the 17 metres per second threshold where a slot starts to chuff.
What does the price cover, and how does it ship?
50 lb, 30.00" W x 14.00" H x 12.50" D external. It ships as a UPS parcel; the price includes shipping in the 48 states. Every Professional cabinet is priced the same way, by its size: this one is 3.04 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 50 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.
Is the GZRW 8XSPL included?
No. This is an enclosure only, cut for the Ground Zero GZRW 8XSPL specifically: the 7.170 inch cutout, the 5.240 inch mounting depth allowance and the 1.32 cubic foot alignment all come from Ground Zero's published parameters. It fits both coil versions; the alignment published here is the SVC or D1. Bring your own driver.
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