Performance Optimized Down Fire Sealed Dual 10" Enclosure Ground Zero GZRW 250-D2 FLAT · Dual 10" Sealed enclosure

The GZRW 250-D2 FLAT, yes, in the dual 2 ohm version. The baffle is cut to 9.13 in, Ground Zero's published cutout, under the 10.87 in frame. The 3.35 inch motor clears the cabinet with 8.08 inch to spare. Run two of the same coil so the chambers match.

Any other 10, no. The airspace is engineered around the GZRW 250-D2 FLAT's own Qts and Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

1.00 cubic feet net per chamber on Ground Zero's published figures: the dual 2 ohm reads Qtc 0.813 with resonance at 42.1 Hz and half power at 37.4 Hz. Ground Zero publishes no sealed volume for the GZRW 250-D2 FLAT. A maximally flat box would take 1.77 cubic feet, a 10 inch cabinet deeper than it is tall, for barely half a hertz more extension, so this one is built at 1.0 cubic foot: the same reach in a box that fits. That is a touch above maximally flat: a small lift near resonance and firm midbass.

Cabinet gain in a vehicle lifts the bottom end further, so in the car this reads deeper than the anechoic figures.

Ground Zero rates the GZRW 250-D2 FLAT at 400 watts RMS per driver, so target 280 to 400 watts RMS per driver at the final load.

Ground Zero sells the GZRW 250-D2 FLAT as dual 2 ohm; a matched pair should share a coil. A pair of dual 2 ohm drivers lands on 2 ohms with each woofer's coils in series and the two woofers in parallel, or 8 ohms all in series. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for, so series wiring is the safe default. Confirm your amplifier's minimum stable impedance first.

The cabinet is 12.18 inches tall measured in the down fire position, and that figure excludes the standoffs. The standoffs hold 1.75 inches under the baffle, so plan your space around a finished stack of roughly 13.93 inches.

The footprint is the standard Performance Optimized down fire platform, 30.00 inches wide by 15.00 deep. Height is the only dimension solved to the driver.

Two drivers sharing one sealed volume load each other: each driver's compression stroke becomes the pressure the other works against, which blurs the alignment either would have alone. A bonded full-height 3/4 inch divider gives each driver its own 1.00 cubic feet and its own polyfill.

It also means a failure in one driver does not unload the other, and the alignment on this page is the alignment in each chamber, not an average across a shared box.

Anechoic F3 is 37.4 Hz per chamber. Above Qtc 0.707 F3 sits below fc, so the response carries a small lift near resonance before it rolls off.

Those figures exclude cabin gain. In a car the cabin's transfer function adds real output below 50 Hz, so in-vehicle response runs deeper than the numbers above.

No. Polyfill is already installed in both chambers as a light wall lining to control internal reflections, and the quantity is chosen so it does not change the acoustic volume.

Do not add more. Packing a sealed box with fill makes it behave as though it were larger, which walks the alignment away from the 1.00 cubic feet per chamber this cabinet was built to.

No driver. This is an enclosure only. You receive the cabinet finished in plush black carpet, one side-mounted pre-wired terminal cup to both positions, the polyfill lining already in place, the standoffs, and a threaded insert kit with stainless machine screws.

The inserts ship loose on purpose: Ground Zero prints no bolt circle for the GZRW 250-D2 FLAT, so you set the driver in the recess, mark its holes, drill and press the inserts. The pair of Ground Zero GZRW 250-D2 FLAT is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 10 inch box.