Performance Optimized Wedge Ported 12" Enclosure | Alpine R2-W12 Single 12" Ported enclosure

35.5 Hz puts the anechoic F3 at 30.2 Hz on 3.49 dB of ripple, and Alpine's own tech sheet shows the same character in their box: 28 to 29 Hz F3 on 4.3 to 5.8 dB of ripple. In the car it spreads 4.73 dB across 25 to 60 Hz, over the 4 dB line the rest of the range holds; the S2-W12 in this line reads 2.82. The port takes 24.26 of the 25.10 inches available and runs at 24.0 metres per second in the channel against a 24.2 limit at 750 watts, 15.6 at the rounded mouth. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz. In this cabinet that lands at 4.8 dB of in-car spread across 25 to 60 Hz.

The raked face is the seat side. A factory rear seat back leans about 20 degrees off vertical, so the cabinet sits flat against it and uses floor a square box wastes. The baffle stays vertical and fires rearward into the trunk, which acts as the acoustic extension into the cabin. This one is 15.14 inches deep at the base and 9.50 at the top, 30.00 wide and 16 tall.

Yes, at 28 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 Alpine R2-W12 at 42 percent of its usable travel at full rated power; without it there is no meaningful number to quote.

Alpine rate the R2-W12 at 750 W RMS and that is the thermal ceiling. The Performance Graphs tab shows the mechanical limit, the power at which the cone reaches the end of its travel in this cabinet: here the cone sits at 42 percent of usable travel at the rating, so heat is what stops you, not travel. A D2 coil is 4 ohms in series or 1 ohm in parallel; run series unless the amplifier is rated for 1 ohm. A D4 is 8 series or 2 parallel.

Below about 22 Hz, yes. The sealed wedge we build for it is louder down there by up to 1.9 dB, because a sealed box rolls off gently where a vented one falls away steeply under tuning. Above that this alignment is the louder of the two for the same power. The Performance Graphs tab plots this cabinet against the 0.75 cu ft sealed wedge we build for this driver (PO 12-S W R2).

It is a triangular slot in the bottom-rear corner: the floor and the raked back wall are two sides, one bevelled panel is the third. It runs across the cabinet, opens into the box through a 3.99 inch gap at the far end and exits through the side panel as the same triangle. Straight, no bend: 24.26 inches of path and 23.0 square inches of channel running at 24.0 metres per second, 55 percent of its turbulence limit. The three mouth edges are rounded over at 1/2 inch, so the opening at the face is 35.4 square inches and the air leaves it at 15.6 metres per second against the 17.0 threshold where a slot port starts to chuff; the panel's throat end is rounded at 3/8 inch for the same reason. The terminal cup is on the other side.

No, and do not add any. Every sealed Proline X enclosure ships with polyfill; a ported one must not, because damping changes the effective volume the port is tuned against. The port here is cut to 24.26 inches for 35.5 Hz. Stuff it and you move the tuning without shortening the port.

No. This is an enclosure only, cut for the Alpine R2-W12 specifically: the 10.880 inch cutout, the 6.500 inch mounting depth allowance and the 1.56 cubic foot alignment all come from Alpine's published parameters. It fits both coil versions; the alignment published here is the D4. Bring your own driver.