{"product_id":"performance-optimized-down-fire-wide-sealed-dual-12-enclosure-hertz-mille-pro-mps-300","title":"Performance Optimized Down Fire Wide Sealed Dual 12\" Enclosure | Hertz Mille Pro MPS 300","description":"\u003cstyle\u003e.df-wrap{font-family:'Helvetica Neue',Arial,sans-serif;line-height:1.75;color:#d6d3d1;max-width:1100px;margin:0 auto;background:#0c0a09}.df-wrap *{box-sizing:border-box}.df-hero{background:linear-gradient(135deg,#0c0a09 0%,#5c3317 100%);padding:54px 36px;text-align:center;color:#fff}.df-hero h2{font-size:2.3em;font-weight:800;text-transform:uppercase;letter-spacing:1.5px;margin:0 0 12px;color:#fff}.df-hero p{font-size:1.1em;font-weight:300;opacity:.93;margin:0 0 22px;color:#d6d3d1}.df-badges{display:flex;justify-content:center;flex-wrap:wrap;gap:10px}.df-badge{background:rgba(184,115,51,.18);border:1px solid #b87333;color:#e8b98d;padding:7px 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td.on{background:rgba(184,115,51,.10);color:#d6d3d1}.df-tier tr:last-child td{border-bottom:none}@media(max-width:600px){.df-hero h2{font-size:1.7em}.df-section,.df-enc,.df-cta,.df-hero{padding-left:20px;padding-right:20px}}\u003c\/style\u003e\n\u003cdiv class=\"df-wrap\"\u003e\n\u003cdiv class=\"df-hero\"\u003e\n\u003ch2\u003eProline X Performance Optimized Down Fire Wide Dual 12\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut for a pair of Hertz Mille Pro MPS 300, S2 or S4\u003c\/p\u003e\n\u003cdiv class=\"df-badges\"\u003e\n\u003cspan class=\"df-badge\"\u003eDown Fire Wide\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eV-Groove and Dado\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eSeparate Chambers\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e22.7 L Per Driver\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stats\"\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e0.807\u003c\/span\u003e\u003cspan class=\"l\"\u003ecu ft net each\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e0.999\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc, MPS 300 S2, per chamber\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e37.0 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff, MPS 300 S2\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e8.75 in\u003c\/span\u003e\u003cspan class=\"l\"\u003ecabinet height, excludes feet\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eThe Down Fire Wide Format\u003c\/h3\u003e\n\u003cp\u003eDown Fire Wide is the same driver in a different shape. The standard Performance Optimized Down Fire cabinet for the Hertz Mille Pro MPS 300 is 30 by 15 inches. This one runs \u003cstrong\u003e41 inches wide by 14 inches deep\u003c\/strong\u003e: 1 inch shallower front to back and 11 inches longer.\u003c\/p\u003e\n\u003cp\u003eFourteen inches is not arbitrary. A 12 inch frame needs about 13 inches of baffle to sit on, so 14 is the practical minimum depth for this driver size. The Hertz Mille Pro MPS 300 frame measures 12.532 inches across and sits on the 14 inch deep baffle with about 0.73 inches of baffle fore and aft. Both positions are laid out along the 41 inch length.\u003c\/p\u003e\n\u003cp\u003eSpreading the airspace along 41 inches instead of 30 means the cabinet does not have to climb to find it. This box stands \u003cstrong\u003e8.75 inches tall\u003c\/strong\u003e, against 10.75 for the standard 30 x 15 Hertz Mille Pro MPS 300 cabinet, both measured in the down fire position without feet. That is 2 inches lower.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\n\u003cp\u003e\u003cstrong\u003eWhich one to choose.\u003c\/strong\u003e The standard 30 x 15 is the pick when length is limited. This one is the pick when height or depth is the limit and you have 41 inches of run. With the 1.75 inch feet installed this cabinet stands 10.5 inches, so measure for that.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003ePerformance, Performance Optimized, and Micro\u003c\/h3\u003e\n\u003cp\u003eProline X builds three tiers of Down Fire enclosure. The difference is not finish or materials, it is whether the cabinet was designed for a category or for a driver, and how much of the fitting work is already done for you.\u003c\/p\u003e\n\u003cdiv class=\"df-tier\"\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003e \u003c\/th\u003e\n\u003cth\u003ePerformance\u003c\/th\u003e\n\u003cth class=\"on\"\u003ePerformance Optimized\u003c\/th\u003e\n\u003cth\u003eMicro Series\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eUniversal. Accepts any subwoofer that clears the published cutout and mounting depth.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003eWoofer specific. Cut for one named subwoofer, with cutout, mounting depth, magnet clearance and displacement drawn in CAD from that driver.\u003c\/td\u003e\n\u003ctd\u003eWoofer specific. Cut for one named subwoofer.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003eFootprint\u003c\/td\u003e\n\u003ctd\u003eSized to the driver diameter. 24.5 by 13.5 inches on the 10 inch.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003eShared 30 by 15 inch platform on most builds. Down Fire Wide variants like this one run long and shallow for under seat fitment.\u003c\/td\u003e\n\u003ctd\u003eCompact per driver footprint. 21.5 by 14.5 inches on the 10 inch.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003eFront baffle\u003c\/td\u003e\n\u003ctd\u003eSingle, 3\/4 inch.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003eDouble layer, outer layer machined as a flush recess. 1.5 inch.\u003c\/td\u003e\n\u003ctd\u003eDouble, 1.5 inch.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003eDriver mounting\u003c\/td\u003e\n\u003ctd\u003eSolid flange. You drill your own mounting holes.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003e8\/32 threaded inserts, stainless machine screws included.\u003c\/td\u003e\n\u003ctd\u003e8\/32 threaded inserts, stainless machine screws included.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003eJoinery\u003c\/td\u003e\n\u003ctd\u003eV-groove and dado, CNC cut.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003eV-groove and dado, CNC cut, perimeter cross brace.\u003c\/td\u003e\n\u003ctd\u003eStack fab, dowel reinforced.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003ePublished alignment\u003c\/td\u003e\n\u003ctd\u003eModeled Qtc profiles across a range of drivers. No single response curve.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003eA real predicted Qtc and F3 for that exact driver, calculated from its own Thiele-Small parameters.\u003c\/td\u003e\n\u003ctd\u003eTarget alignment described in the listing.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003eCarpet\u003c\/td\u003e\n\u003ctd\u003eGray standard, black optional.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003ePlush black.\u003c\/td\u003e\n\u003ctd\u003ePlush black.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"a\"\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e1 year limited.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003e1 year limited.\u003c\/td\u003e\n\u003ctd\u003e2 years.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-note\"\u003e\u003cp\u003e\u003cstrong\u003eFeet ship with every tier, uninstalled on purpose.\u003c\/strong\u003e Mount them where your floor wants them for a down fire install, or leave them off and run the cabinet front firing or up firing. The orientation is yours to choose.\u003c\/p\u003e\u003c\/div\u003e\n\u003cdiv class=\"df-note\"\u003e\u003cp\u003e\u003cstrong\u003eThis page is a Performance Optimized enclosure.\u003c\/strong\u003e The cutouts, the cabinet height and the airspace all come from the Hertz Mille Pro MPS 300's own published numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eBuilt Around a Pair of MPS 300s\u003c\/h3\u003e\n\u003cp\u003eBoth baffle positions are bored to the MPS 300's \u003cstrong\u003e283mm cutout\u003c\/strong\u003e, 11.14 inches, and the motor clears the top panel with 4.535 inches to spare, so the height of this cabinet is set by the airspace Hertz asks for, not by the \u003cstrong\u003e3.465 inch mounting depth\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eEach MPS 300 carries \u003cstrong\u003e16.8mm of one way Xmax\u003c\/strong\u003e behind a 38mm voice coil and a high density flux ferrite motor, with a polypropylene cone. Power handling is 500 watts RMS and 1000 watts peak per driver, \u003cstrong\u003e1000 watts RMS across the pair\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eThe depth comes from a \u003cstrong\u003e24 Hz free air resonance paired with a 64.9 liter Vas\u003c\/strong\u003e on the S2, and 23 Hz with 62.1 liters on the S4. Each driver is sold as the MPS 300 S2 at 2 ohms or the MPS 300 S4 at 4 ohms, both single voice coil. Use two of the same model; mismatched drivers between chambers will not track each other.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eNet Volume and Alignment\u003c\/h3\u003e\n\u003cp\u003eEach chamber holds \u003cstrong\u003e0.807 cubic feet net\u003c\/strong\u003e, \u003cstrong\u003e1.615 cubic feet net across both\u003c\/strong\u003e, from 1.81 cubic feet gross after the divider, the bracing and each driver's 0.08 cubic feet of displacement (estimated, no manufacturer figure).\u003c\/p\u003e\n\u003cp\u003eHeight is the free dimension. With the footprint fixed at 41 by 14, the cabinet height was solved to put each chamber on the same airspace as the standard 30 x 15 box, which holds 0.80 cubic feet net per chamber, and the motor clears the top panel with 4.535 inches to spare. Same air, same alignment, lower cabinet.\u003c\/p\u003e\n\u003cp\u003eComputed from Hertz's published Thiele-Small parameters: \u003cstrong\u003eMPS 300 S2: Qtc 0.999, Fc 47.0 Hz, F3 37.0 Hz\u003c\/strong\u003e; \u003cstrong\u003eMPS 300 S4: Qtc 0.810, Fc 44.3 Hz, F3 39.4 Hz\u003c\/strong\u003e per chamber.\u003c\/p\u003e\n\u003cp\u003eEach chamber matches Hertz's own sealed recommendation of 22.7 liters per driver. Pay attention to the model choice, because \u003cstrong\u003eit reverses from the 10 inch MPS 250\u003c\/strong\u003e: on the MPS 300 the S4 is the better damped driver, Qts 0.42 against 0.51, with far more motor force, 18.7 T·m against 12.3. The S4 gives the more controlled alignment; the S2 reaches about 2.4 Hz lower with a modest lift at the corner.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\n\u003cp\u003e\u003cstrong\u003eTrue net, not marketing net.\u003c\/strong\u003e Internal volume is calculated from the machined cavity dimensions and the driver's displacement, not estimated from external dimensions minus wall thickness.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eTwo Chambers, Not One\u003c\/h3\u003e\n\u003cp\u003eThis enclosure follows the Proline X standing design rule for dual sealed builds: \u003cstrong\u003etwo fully separate chambers\u003c\/strong\u003e divided by a bonded full-height 3\/4 inch MDF panel.\u003c\/p\u003e\n\u003cp\u003eTwo drivers sharing one 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 divider removes that. Each Hertz Mille Pro MPS 300 gets its own 0.807 cubic feet net and its own polyfill.\u003c\/p\u003e\n\u003cp\u003eOn a 41 inch cabinet the divider does structural work as well, tying the front and rear walls together at the centre of the span. One shared side-mounted terminal cup feeds both driver positions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eDown Fire Wide Construction\u003c\/h3\u003e\n\u003cp\u003eCut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3\/4 inch MDF, a dense 48.5 lb\/ft³ board with a 200 psi internal bond and 410,000 psi MOE. Every panel joint is a machined interlocking groove that mechanically locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Corners are square on Down Fire cabinets.\u003c\/p\u003e\n\u003cp\u003eThe cabinet measures \u003cstrong\u003e41 inches wide by 14 inches deep by 8.75 inches tall, measured in the down fire position\u003c\/strong\u003e. Feet ship with the enclosure but are not installed. With the 1.75 inch feet on, the cabinet stands 10.5 inches, so plan the space around where you intend to mount them.\u003c\/p\u003e\n\u003cdiv class=\"df-grid\"\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003e1.5 Inch Double Baffle\u003c\/h4\u003e\n\u003cp\u003eTwo \u003cstrong\u003e3\/4 inch layers laminated to 1.5 inches\u003c\/strong\u003e, with the outer layer machined as a flush recess so the driver bolts to the inner layer. 8\/32 threaded inserts at the driver position, stainless machine screws included.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eSeparate Chambers\u003c\/h4\u003e\n\u003cp\u003eA bonded \u003cstrong\u003efull-height 3\/4 inch divider\u003c\/strong\u003e gives each driver its own 0.807 cubic feet net and its own polyfill, and ties the walls together mid span.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eOne Shared Terminal Cup\u003c\/h4\u003e\n\u003cp\u003eProline X ABS and carbon fiber composite cup with stainless hardware and copper ring terminals, \u003cstrong\u003eside mounted\u003c\/strong\u003e and pre-wired in 12 gauge OFC to both driver positions in parallel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003ePolyfill Installed\u003c\/h4\u003e\n\u003cp\u003ePolyfill is installed as a light wall lining in both chambers to control internal reflections. It does not change the acoustic volume, so do not add more.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- ENCLOSURE PERFORMANCE SLOT --\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003ePower and Warranty\u003c\/h3\u003e\n\u003cp\u003eEach driver is rated \u003cstrong\u003e500 watts RMS and 1000 watts peak\u003c\/strong\u003e, \u003cstrong\u003e1000 watts RMS combined\u003c\/strong\u003e. Both models are single voice coil, so there is no coil wiring decision at the driver. One side-mounted cup feeds both positions in parallel: a pair of S2 drivers presents 1 ohm, a pair of S4 drivers 2 ohms. Confirm that against your amplifier's minimum stable load before powering up.\u003c\/p\u003e\n\u003cp\u003eHertz suggests a \u003cstrong\u003e15 Hz subsonic filter at 24 dB per octave\u003c\/strong\u003e and a 70 to 80 Hz low pass for sealed applications. The enclosure carries a 1 year limited warranty. Bring your own pair of MPS 300 S2 or MPS 300 S4; the drivers are purchased separately.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-cta\"\u003e\n\u003ch3\u003eCut for the Driver, Not the Catalog\u003c\/h3\u003e\n\u003cp\u003eDown Fire Wide, 41 inches long and 14 deep, cut for one driver model and built one at a time in Tullahoma, Tennessee. Questions on fitment or amplifier matching, call us at 931-563-5151.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":47345338712153,"sku":"PO 12D-S DFW MPS","price":369.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0689\/1389\/files\/PO_12D_S_DFW_MPS_Front.jpg?v=1790650471","url":"https:\/\/audiointensity.com\/products\/performance-optimized-down-fire-wide-sealed-dual-12-enclosure-hertz-mille-pro-mps-300","provider":"Audio Intensity","version":"1.0","type":"link"}