Professional Series Ported 15" Enclosure Image Dynamics IDMAX15 V4 · Single 15" Ported enclosure

Image Dynamics publish a Qts of 0.95 at 30 Hz for the D2 coil, and that figure is genuine: their Qes and Qms reproduce it and the motor constants agree. A driver that damped wants a large box and a low vent, and their own manual says so, recommending 3.0 cubic feet gross at 27 Hz for the Universal alignment. This cabinet lands on it: 4.12 gross, 2.72 net after the driver, port and braces, vented at 26.5 Hz, which is where the in-car curve comes out flattest. Passband ripple sits at 4.46 dB, and that number is the driver's Q rather than the box; tuning higher or lower makes it worse, not better. 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 IDMAX15 V4 did not clear the ripple 5.51 dB over 4.5 gate there: the nearest wedge that fits is 24.5 by 11.25 by 17.98 inches with a 23.0 square inch port, and no tuning, width or depth inside that envelope passes. The slot on this box reaches 45.4 square inches. 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, an Image Dynamics logo acrylic, and a port and excursion budget checked at 720 W. It carries a 2 year warranty against 1.

Threaded inserts pressed into the baffle on the published 15.551 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 24 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 Image Dynamics IDMAX15 V4 at 36 percent of its usable travel at 720 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, 2.85 cubic feet vented at 30.0 Hz, against Image Dynamics's recommended sealed box, 2.00 cu ft (2.00 gross, 1.74 net after the driver), so you can judge it yourself.

It is a vertical slot beside the woofer, the full height of the cavity, 2.75 inches wide and 45.4 square inches. It runs 9.50 inches to the back wall and turns once along it for 20.46 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 10.4 metres per second at 720 W, 31 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 7.2 metres per second against the 17 metres per second threshold where a slot starts to chuff.

70 lb, 36.00" W x 18.00" H x 16.00" 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 6.00 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 70 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.

No. This is an enclosure only, cut for the Image Dynamics IDMAX15 V4 specifically: the 14.764 inch cutout, the 10.433 inch mounting depth allowance and the 2.85 cubic foot alignment all come from Image Dynamics's published parameters. It fits both coil versions; the alignment published here is the D2. Bring your own driver.