Performance Optimized Wedge Sealed Dual 12" Enclosure Ampere Audio AA-2.75 12 · Dual 12" Sealed enclosure

The AA-2.75 12, yes, in both coil versions. The baffle is cut to 11.01 in, Ampere's published cutout, under the 12.83 in frame. The 7.50 inch motor clears the cabinet with 0.75 inch to spare. Run two of the same coil so the chambers match.

Any other 12, no. The airspace is engineered around the AA-2.75 12'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.

0.82 cubic feet net per chamber on Ampere's published figures: the dual 2 ohm reads Qtc 0.665 with resonance at 56.8 Hz and half power at 60.5 Hz, and the dual 4 ohm reads Qtc 0.659 with resonance at 49.9 Hz and half power at 53.8 Hz. One cabinet serves both coils, built to the volume that keeps both closest to maximally flat. That is a slightly over-damped alignment: a gentle, early rolloff and tight transients rather than a flat top.

The 7.50 inch mounting depth sets the minimum cabinet depth here, so the airspace is what the motor allows rather than a free choice.

Ampere rates the AA-2.75 12 at 1000 watts RMS per driver, so target 700 to 1000 watts RMS per driver at the final load.

Ampere sells the AA-2.75 12 as dual 2 ohm and dual 4 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. A pair of dual 4 ohm drivers lands on 4 ohms with each woofer's coils in series and the woofers in parallel, or 1 ohm with everything in parallel. 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 seat-side face carries a 20 degree rake that matches the lean of a factory rear seat back, so the cabinet sits flush against it and the cargo space in front stays usable. The baffle is the vertical trunk-lid-side face, so the drivers fire rearward into the trunk cavity.

The trunk acts as an acoustic extension for the sealed box, and the cabin adds real output below 50 Hz, so in-vehicle response runs deeper than the anechoic 60.5 Hz on the dual 2 ohm and 53.8 Hz on the dual 4 ohm on this page.

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 0.82 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 60.5 Hz on the dual 2 ohm and 53.8 Hz on the dual 4 ohm per chamber. 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 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 0.82 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 with the gloss black acrylic baffle insert, one side-mounted pre-wired terminal cup to both positions, the polyfill lining already in place, and a threaded insert kit with stainless machine screws.

The inserts ship loose on purpose: Ampere prints no bolt circle for the AA-2.75 12, so you set the driver in the recess, mark its holes, drill and press the inserts. The pair of Ampere Audio AA-2.75 12 is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 12 inch box.