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

Because two drivers in a shared sealed volume interact acoustically. Each driver's compression phase becomes the pressure environment the other driver 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 completely. Each DMD-SH gets its own 0.80 cubic feet net, its own polyfill, and produces its own clean sealed alignment. Separate chambers are the standing design rule on every Proline X dual sealed enclosure.

Acoustically identical per driver, roughly 6 dB more maximum output. Both give each driver 0.80 cubic feet net and the same Qtc figures, 0.856 on the D2 and 0.981 on the D4. The difference is physical: both share the 30 by 15 inch footprint, but the single stands 6.125 inches tall and the dual stands 10.125. Combined power handling doubles to 500 watts RMS. The single fits under seats; the dual is a cargo floor or rear-wall build.

Because Diamond's enclosure table does not reconcile with the Thiele-Small parameters printed on the same page. Their table lists the DMD102SH at Qtc 0.78 in 0.45 cubic feet. Running their own published Qts of 0.66 and Vas of 15.4 liters through standard sealed box math at that volume produces 0.98 instead. Every variant is off in the same direction by roughly 0.2 to 0.3, which is too large to be explained by a gross versus net volume convention. We publish figures computed directly from the driver parameters.

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 you choose how to wire the two coils on each driver and that determines the load the amplifier sees through the cup. Wire both drivers identically, since mismatched wiring between the two chambers will split power unevenly. Confirm the resulting load against your amplifier's minimum stable impedance before powering the system.

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 1.003 per chamber. The DMD104SH runs a Qts of 0.77 with 16.4 T and 8.8mm, landing at Qtc 0.981. The D4 has the stronger motor and more excursion capability, the D2 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.

Side mounted, and there is one cup serving both chambers 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 fully 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 is what keeps both chambers airtight under sustained pressure cycling. The chamber divider is a full-height bonded 3/4 inch panel. Front baffles are double-layer at 1.5 inches, two bonded 3/4 inch sheets, at both driver positions. Perimeter cross-bracing and pre-installed polyfill in each chamber complete the build. Assembled and inspected in Tullahoma, Tennessee.

No. This listing is for the enclosure only. Bring your own pair of Diamond Audio DMD102SH or DMD104SH subwoofers. The cutouts and mounting depth are direct fit at both driver positions for either version.