{"product_id":"performance-optimized-down-fire-sealed-12-enclosure-diamond-audio-dmd-sh","title":"Performance Optimized Down Fire Sealed 12\" Enclosure | Diamond Audio DMD-SH","description":"\u003cp\u003eThe \u003cstrong\u003ePerformance Optimized Down Fire Sealed 12\" Enclosure for the Diamond Audio DMD-SH\u003c\/strong\u003e is a low-profile sealed cabinet built around Diamond's shallow-mount DMD 12\" subwoofer. At 8.3125 inches tall on a 30 by 15 inch footprint, it puts a full 12 into cargo floors and rear-wall positions where a conventional 12 will not go.\u003c\/p\u003e\u003cp\u003eThe DMD-SH 12 is available as the \u003cstrong\u003eDMD122SH\u003c\/strong\u003e (dual 2Ω) or \u003cstrong\u003eDMD124SH\u003c\/strong\u003e (dual 4Ω), both rated 300 watts RMS and 600 watts max with a \u003cstrong\u003e3.00 inch mounting depth\u003c\/strong\u003e — the same depth as the 10 inch model. Cutout is 11.06 inches, total diameter 12.83 inches. The driver features an aluminum heatsink dust cap over a high-strength paper cone, die-cast shallow frame, vented pole for cooler operation, oversized push terminals, black spider with woven tinsel leads, and a wrap-around ABS mounting gasket. Diamond states the motor and suspension symmetry are \u003cstrong\u003eKlippel optimized\u003c\/strong\u003e.\u003c\/p\u003e\u003cp\u003eThe coil variants differ meaningfully here. The DMD122SH runs a Qts of 0.77 with 13.7 T of motor force and 7.9mm Xmax. The DMD124SH runs a Qts of 0.91 with 16.4 T and 8.8mm Xmax. The D4 has the stronger motor and more excursion, the D2 considerably better damping.\u003c\/p\u003e\u003cp\u003eThe 1.25 cubic foot net volume produces \u003cstrong\u003eQtc 1.137 with F3 at 51.4 Hz on the DMD122SH\u003c\/strong\u003e, and \u003cstrong\u003eQtc 1.336 with F3 at 53.6 Hz on the DMD124SH\u003c\/strong\u003e, computed from Diamond's published Thiele-Small parameters.\u003c\/p\u003e\u003cp\u003eTwo things worth stating plainly. First, we build this larger than Diamond's suggested 0.75 cubic feet, which would put the D2 near Qtc 1.20 and the D4 above 1.42. At 1.25 net the alignment is better damped on both variants with 1 to 2 Hz more extension, and Diamond's manual presents their enclosure table as a suggestion rather than a specification.\u003c\/p\u003e\u003cp\u003eSecond, the figures above are \u003cstrong\u003ecomputed from the T\/S parameters Diamond publishes\u003c\/strong\u003e, and they do not match the Qtc values printed in Diamond's enclosure table. Running their own Qts and Vas through standard sealed box math produces higher Qtc than their table shows, by roughly 0.2 to 0.3 across every variant. We publish the computed number because it follows from the driver data.\u003c\/p\u003e\u003cp\u003eBe aware that the DMD124SH has a free-air Qts of 0.91. Since system Qtc can never fall below the driver's Qts, that variant is underdamped in any sealed enclosure regardless of volume. The DMD122SH at 0.77 has more headroom and is the better sealed performer of the two.\u003c\/p\u003e\u003cp\u003eFiring down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz, and in-car response extends well below the anechoic figure.\u003c\/p\u003e\u003cp\u003eConstruction is the full Proline X Performance Optimized platform: ShopSabre CNC-cut Langboard Elite MDF with \u003cstrong\u003eV-groove and dado joinery\u003c\/strong\u003e, perimeter cross-bracing, and a \u003cstrong\u003edouble-layer 1.5 inch front baffle\u003c\/strong\u003e (two 3\/4 inch sheets bonded) for maximum baffle rigidity and driver isolation. Corners are square on Down Fire cabinets. The driver fires down into the floor with the terminal cup \u003cstrong\u003eside mounted\u003c\/strong\u003e, keeping the connection accessible with the cabinet in place. Terminal cup is our Proline X ABS\/carbon fiber composite pre-wired with 12 gauge OFC.\u003c\/p\u003e\u003cp\u003eBring your own DMD122SH or DMD124SH. Both are dual voice coil, so you set your final impedance at the driver.\u003c\/p\u003e\u003cp\u003eManufactured in Tullahoma, Tennessee. 1-year enclosure warranty.\u003c\/p\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44540389818457,"sku":"PO 12-S DF DMD","price":249.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0689\/1389\/files\/proline-x-micro-series-dual-15-sealed-enclosure-built-for-resonix-gus-15subwoofer-enclosuresproline-x-9360178_0b88275c-e62b-4739-aae8-d4220e4e6a14.jpg?v=1787112325","url":"https:\/\/audiointensity.com\/products\/performance-optimized-down-fire-sealed-12-enclosure-diamond-audio-dmd-sh","provider":"Audio Intensity","version":"1.0","type":"link"}