Professional Series Ported 15" Enclosure | Sundown Audio X-Series XV4 15

Sundown publishes a Qts of 0.440 for the X-Series XV4 15 D2, and the figure checks out against their own Qes of 0.490 and Qms of 4.080. Sundown does not recommend this driver sealed; their own ported figure is 4.25 cubic feet at 32 Hz through a 68 square inch port. This cabinet is built to that figure: 4.27 cubic feet net, tuned to 32.0 Hz. The one place it departs from Sundown's sheet is the port, 82.5 square inches against their 68, because at the coil's rated power, 2750 W, a 68 square inch slot would put the mouth over 17 metres per second. The port stays clean to 2751 W before mouth velocity becomes the limiting factor, the cone peaks at 13.8 of its 30.0 mm at rated power, and ripple across the passband holds at 5.19 dB. 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 X-Series XV4 15 does not fit that envelope at all: no tuning, width or depth inside it carries a 12.95 inch deep 15 inch driver at 2750 W. This box is the chassis with the width, depth and port to carry it. 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 Sundown Audio logo acrylic, and a port and excursion budget checked at 2750 W. It carries a 2 year warranty, against 1 year on the Performance Optimized lines.

Sundown Audio does not publish the mounting hole locations for the X-Series XV4 15, so we cannot install the threaded inserts before it ships. The threaded insert kit comes in the box instead: inserts sized to the woofer, the correct drill bit, 2.5 inch allen-head screws, an allen key and woofer gasket tape. You set the inserts when you mount the woofer, and this box ships with one kit.

Yes, at 25 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 Sundown Audio X-Series XV4 15 at 46 percent of its usable travel at 2750 W.

Not one we can show you. We do not build a sealed enclosure for the Sundown Audio X-Series XV4 15 and Sundown Audio mark it Not Recommended for a sealed enclosure, 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 25 Hz subsonic filter takes over; around 32.0 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, 5.00 inches wide and 82.5 square inches. It runs 16.25 inches to the back wall and turns once along it for 12.36 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 21.6 metres per second at 2750 W, 31 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 17.0 metres per second against the 17 metres per second threshold where a slot starts to chuff.

90 lb packed, 33.50" W x 18.00" H x 25.00" D external. Every Professional cabinet is priced the same way, by its size: this one is 8.72 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 90 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.

No. This is an enclosure only, cut for the Sundown Audio X-Series XV4 15 specifically: the 13.930 inch cutout, the 12.950 inch mounting depth allowance and the 4.27 cubic foot alignment all come from Sundown Audio's published parameters. It fits both coil versions; the alignment published here is the D2. Bring your own driver.