Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure Diamond Audio DMD-SH · Dual 10" Sealed enclosure

Because it is only 12 inches deep. The standard Performance Optimized Down Fire cabinet for the Diamond Audio DMD-SH is 30 wide by 15 deep, and this version is for spaces 3 inches shallower than that, under a rear bench or on a narrow cargo floor.

Airspace has to come from somewhere. Losing depth means recovering it along the length, so the cabinet runs 41 inches long and stands 9.6875 inches tall. If you have 15 inches of depth, the standard cabinet is shorter in length and is the better pick; if you have 12 inches of depth and 41 inches of run, this is the shape that works.

Same driver, different shape. The standard cabinet is 30 by 15 by 10.125 inches and was built to 0.80 cubic feet net per chamber. This cabinet is 41 by 12 by 9.6875 inches and holds 0.803 cubic feet net per chamber.

The airspace is essentially the same, within about a hundredth of a cubic foot, so the two behave the same way. The choice is about the space you have: the standard box is deeper and shorter in length, this one is long and shallow.

Because two drivers in a shared sealed volume interact acoustically. Each driver's compression phase becomes the pressure environment the other is working against, which smears transient response and blurs the alignment each would have on its own.

A full-height bonded 3/4 inch MDF divider eliminates that. Each DMD-SH gets its own 0.803 cubic feet net and its own polyfill, and produces its own sealed alignment. Separate chambers are the standing design rule on every Proline X dual sealed enclosure.

These two differ more than most dual-impedance pairs. The DMD102SH runs a Qts of 0.66 with 13.7 T of motor force and 7.9mm of Xmax, landing at Qtc 0.855, Fc 62.2 Hz, F3 53.2 Hz per chamber. The DMD104SH runs a Qts of 0.77 with 16.4 T and 8.8mm, landing at Qtc 1.002, Fc 63.1 Hz, F3 49.6 Hz.

The D4 has the stronger motor and more excursion; the D2 has noticeably better damping. Check what load your amplifier is stable into first. If either works, choose the D2 for accuracy and the D4 for output. Whichever you pick, use two of the same version.

The enclosure uses one side-mounted Proline X terminal cup with a single pair of posts, pre-wired in 12 gauge OFC to both driver positions in parallel. You do not wire the two chambers separately at the amplifier.

Final impedance is set at the drivers. Each DMD-SH is a dual voice coil subwoofer, so how you wire the two coils on each driver determines the load the amplifier sees through the cup. Wire both drivers identically, and confirm the resulting load against your amplifier's minimum stable impedance before powering the system.

Side mounted, and there is one cup serving both driver positions rather than one per chamber. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup regardless of alignment, whether standard, wedge, or down fire. On this cabinet that keeps the connection accessible with the enclosure in its installed position, since both baffles face the floor. The cup is our Proline X ABS and carbon fiber composite unit, recessed, with stainless hardware, copper ring terminals, and pre-wired 12 gauge OFC.

V-groove and dado joinery, CNC-cut on ShopSabre routers from Langboard Elite MDF. Every panel joint is a machined interlocking groove that mechanically locks the panels before adhesive is applied, which keeps both chambers airtight under sustained pressure cycling. The chamber divider is a full-height bonded 3/4 inch panel, which also ties the front and rear walls together across the 41 inch span. The front baffle is a double layer at 1.5 inches, two bonded 3/4 inch sheets with the outer layer machined as a flush recess, at both driver positions. Polyfill is installed in each chamber as a light wall lining. Assembled and inspected in Tullahoma, Tennessee.

No. This listing is for the enclosure only. Bring your own pair of Diamond Audio DMD102SH or DMD104SH. The cutouts and mounting depth are direct fit for either version, and the feet ship uninstalled in the box.