Dayton Audio Ultimax II UMII12 Dual Box: Ported 12" Professional Series Enclosure Dual 12" Ported enclosure

Both drivers share one chamber and one port rather than sitting in separate boxes, so the pair works against the whole volume and the port is sized for the pair rather than doubled. The port carries 36.2 square inches of area at 32.5 Hz, and the design power for the velocity and excursion checks is 1920 W for the pair. Passband ripple holds at 1.75 dB across the tuning, with F3 at 35.1 Hz. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz, and this tuning is where that sum comes out flattest across 25 to 60 Hz.

A single Ultimax II UMII12 also builds in the Performance Optimized ported wedge and ported down-fire, the smaller and cheaper single-driver boxes. A pair takes this Professional cabinet: one shared chamber on a 2.25 inch three-layer baffle with both woofers flush in the outer layer, and a slot port gated at 1920 W for the pair. It carries a 2 year warranty, against 1 year on the Performance Optimized lines.

Threaded inserts pressed into the baffle on the published 11.890 inch bolt circle, stainless machine screws included. The inserts are in the baffle when it arrives; the machine screws are in the terminal cup bag.

Yes, at 26 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 Dayton Audio Ultimax II UMII12 at 43 percent of its usable travel at 1920 W.

Not one we can show you. We do not build a sealed enclosure for the Dayton Audio Ultimax II UMII12 and Dayton Audio publish no sealed volume for it, so the Performance Graphs tab carries no ported-versus-sealed chart: the only sealed box left to plot would be this cabinet stuffed and sealed, which nobody would build, and a comparison against it would tell you nothing you could buy. What a vented box gives up is the region below tuning, where the cone unloads and the 26 Hz subsonic filter takes over; around 32.5 Hz the vent carries the load and cone travel drops to its minimum, which no sealed alignment can do.

It is a vertical slot beside the woofer, the full height of the cavity, 2.50 inches wide and 36.2 square inches. It runs 7.75 inches to the back wall and turns once along it for 9.91 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 23.6 metres per second at 1920 W, 54 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 15.7 metres per second against the 17 metres per second threshold where a slot starts to chuff.

63 lb, 42.00" W x 16.00" H x 14.00" D external. Every Professional cabinet is priced the same way, by its size: this one is 5.44 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 63 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.

No. This is an enclosure only, cut for the Dayton Audio Ultimax II UMII12 specifically: the 11.272 inch cutout, the 7.059 inch mounting depth allowance and the 2.82 cubic foot alignment all come from Dayton Audio's published parameters. Dayton make the UMII12 in one version, dual 2 ohm (UMII12-22). Bring your own driver.