AudioControl EPICX8 Box: Sealed 8" Down Fire Enclosure Single 8" Sealed enclosure

The EPICX8, yes, in both coil versions. The baffle is cut to 6.900 in for AudioControl's 8.500 in frame. The 4.10 inch motor clears the cabinet with 0.75 inch to spare.

Any other 8, no. The airspace is engineered around the EPICX8'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.

0.67 cubic feet net on AudioControl's published figures: the EPICX8 D2 (dual 2 ohm) reads Qtc 0.728 with resonance at 54.7 Hz and half power at 53.1 Hz, and the EPICX8 D4 (dual 4 ohm) reads Qtc 0.720 with resonance at 55.3 Hz and half power at 54.3 Hz. One cabinet serves both coils. AudioControl recommends 0.4 cubic feet for this driver; the 4.10 inch motor sets the minimum height of this down fire, which holds more. That is a touch above maximally flat: a small lift near resonance and firm midbass.

The 4.10 inch mounting depth sets the minimum cabinet height here, so the airspace is what the motor allows rather than a free choice.

AudioControl rates the EPICX8 at 400 watts RMS, so target 280 to 400 watts RMS at the final load.

AudioControl sells the EPICX8 as EPICX8 D2 (dual 2 ohm) and EPICX8 D4 (dual 4 ohm): the EPICX8 D2 (dual 2 ohm) is two 2 ohm coils, 4 ohms in series or 1 ohm in parallel; the EPICX8 D4 (dual 4 ohm) is two 4 ohm coils, 8 ohms in series or 2 ohms 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 5.60 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 7.35 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, and here it is the EPICX8's 4.10 inch motor that sets it.

The baffle is two bonded 3/4 inch sheets, 1.5 inches through. A single 3/4 inch panel flexes under the pressure an 8 inch woofer puts on it at 400 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 AudioControl's 8.500 inch frame, so the driver bolts to the inner layer.

Anechoic F3 is 53.1 Hz on the EPICX8 D2 (dual 2 ohm) and 54.3 Hz on the EPICX8 D4 (dual 4 ohm). 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 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 0.67 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 are not pre-installed: AudioControl publishes no bolt circle for the EPICX8, so set the driver in its recess, mark its holes, drill and press the inserts. The AudioControl EPICX8 is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 8 inch box.