Professional Series Ported Dual 12" Enclosure Stereo Integrity SQL-12 · 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 61.6 square inches of area at 29.0 Hz, and the design power for the velocity and excursion checks is 2400 W for the pair. Passband ripple holds at 1.28 dB across the tuning, with F3 at 25.0 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.

Every driver is run through the Performance Optimized wedge and down-fire before this chassis; the Professional box is where a driver lands when that smaller envelope, 30 inches wide and 18 inches deep with a triangular side port, cannot give it what it needs at its rated power. The SQL-12 did not clear the port gate there. The calmest wedge port that fits that envelope is 24.7 square inches at 28.5 by 10.25 by 15.89 inches, and its mouth runs 17.8 metres per second at 1000 W against the 17 metres per second line where a port starts to chuff. That port would stay clean to about 911 W. The slot on this box reaches 61.6 square inches and holds the mouth at 16.8 metres per second at 2400 W. An under-ported box does not fail quietly. Air speed at the mouth rises with power; past the chuff line the flow turns turbulent and the port is audible on every note. The turbulence also chokes the port, so the box behaves as if it were tuned higher than it is, loses output near tuning, and lets the cone travel further below tuning than the design allows. This chassis is a full-size front-firing box on a 2.25 inch baffle built from three 3/4 inch layers with the woofer flush-mounted in the outer layer, a Stereo Integrity logo acrylic, and a port and excursion budget checked at 2400 W. It carries a 2 year warranty against 1.

Threaded inserts pressed into the baffle on the woofer's mounting hole locations, stainless machine screws included. The inserts are in the baffle when it arrives; the machine screws are in the terminal cup bag.

Yes, at 23 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 Stereo Integrity SQL-12 at 52 percent of its usable travel at 2400 W.

The two alignments converge at the bottom of the band on this driver rather than crossing cleanly, so there is no meaningful subsonic advantage either way. Above 25 Hz the vent is the louder of the two for the same power. The Performance Graphs tab plots this cabinet, 3.45 cubic feet vented at 29.0 Hz, against the 1.00 cu ft sealed wedge we build for this driver (PO 12-S W SQL12) per driver, 2.00 cu ft for the pair, so you can judge it yourself.

It is a vertical slot beside the woofer, the full height of the cavity, 4.25 inches wide and 61.6 square inches. It runs 12.00 inches to the back wall and turns once along it for 23.79 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 22.2 metres per second at 2400 W, 49 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 16.8 metres per second against the 17 metres per second threshold where a slot starts to chuff.

74 lb, 40.00" W x 16.00" H x 20.00" D external. It ships as a UPS parcel; the price includes shipping in the 48 states. Every Professional cabinet is priced the same way, by its size: this one is 7.41 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 74 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.

No. This is an enclosure only, cut for the Stereo Integrity SQL-12 specifically: the 11.330 inch cutout, the 7.000 inch mounting depth allowance and the 3.45 cubic foot alignment all come from Stereo Integrity's published parameters. It fits both coil versions; the alignment published here is the Dual 2 Ohm. Bring your own driver.