Performance Optimized Down Fire Sealed 12" Enclosure Ground Zero GZRW 300-D2 FLAT · Single 12" Sealed enclosure

The GZRW 300-D2 FLAT, yes, in the dual 2 ohm version. The baffle is cut to 10.94 in, Ground Zero's published cutout, under the 12.72 in frame. The 3.66 inch motor clears the cabinet with 4.41 inch to spare.

Any other 12, no. The airspace is engineered around the GZRW 300-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.

1.34 cubic feet net on Ground Zero's published figures: the dual 2 ohm reads Qtc 0.707 with resonance at 37.8 Hz and half power at 37.8 Hz. Ground Zero publishes no sealed volume for the GZRW 300-D2 FLAT, so the cabinet is solved to the maximally flat alignment, Qtc 0.707. That is maximally flat, the reference sealed alignment.

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 300-D2 FLAT at 450 watts RMS, so target 315 to 450 watts RMS at the final load.

Ground Zero sells the GZRW 300-D2 FLAT as dual 2 ohm: the dual 2 ohm is two 2 ohm coils, 4 ohms in series or 1 ohm in parallel. A parallel load at or under 1 ohm needs an amplifier rated for it. Confirm your amplifier's minimum stable impedance first.

The cabinet is 8.82 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 10.57 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.

The baffle is two bonded 3/4 inch sheets, 1.5 inches through. A single 3/4 inch panel flexes under the pressure a 12 inch woofer puts on it at 450 watts, which smears output and works the driver loose over time; the second layer stiffens the face and gives the mounting hardware twice the material to bite.

The outer layer is machined as a flush recess to Ground Zero's 12.72 inch frame, so the driver bolts to the inner layer.

Anechoic F3 is 37.8 Hz. Below Qtc 0.707 the rolloff is gentle and F3 sits above fc, which is what an over-damped sealed box does.

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 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 1.34 cubic feet 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, 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 300-D2 FLAT, so you set the driver in the recess, mark its holes, drill and press the inserts. The Ground Zero GZRW 300-D2 FLAT is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 12 inch box.