{"product_id":"performance-optimized-down-fire-wide-sealed-12-enclosure-hertz-mille-pro-mp-300","title":"Performance Optimized Down Fire Wide Sealed 12\" Enclosure | Hertz Mille Pro MP 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 16px;border-radius:18px;font-size:.8em;font-weight:600}.df-stats{display:flex;flex-wrap:wrap;background:#1c1917}.df-stat{flex:1 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class=\"df-wrap\"\u003e\n\u003cdiv class=\"df-hero\"\u003e\n\u003ch2\u003eProline X Performance Optimized Down Fire Wide 12\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut for the Hertz Mille Pro MP 300, D2.3 or D4.3\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\"\u003e14\" Depth\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e86 dB Sensitivity\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\"\u003e1.512\u003c\/span\u003e\u003cspan class=\"l\"\u003ecu ft net\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e0.694\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc, MP 300 D4.3\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e40.4 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff, MP 300 D4.3\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e8 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 MP 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 MP 300 frame measures 12.638 inches across and sits on the 14 inch deep baffle with about 0.68 inches of baffle fore and aft. \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 inches tall\u003c\/strong\u003e, against 8.125 for the standard 30 x 15 Hertz Mille Pro MP 300 cabinet, both measured in the down fire position without feet. That is 0.125 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 9.75 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 cutout, the cabinet height and the airspace all come from the Hertz Mille Pro MP 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 the Hertz MP 300\u003c\/h3\u003e\n\u003cp\u003eThe baffle is bored to the MP 300's \u003cstrong\u003e287mm cutout\u003c\/strong\u003e, 11.30 inches, and the internal height is set by its \u003cstrong\u003e6.457 inch mounting depth\u003c\/strong\u003e. The driver bolts to 8\/32 threaded inserts with stainless machine screws included, and at 8.63 kg it is a heavy motor that wants a baffle it can pull against.\u003c\/p\u003e\n\u003cp\u003eHertz publishes separate Thiele-Small sets for the two coil versions: the \u003cstrong\u003eMP 300 D4.3\u003c\/strong\u003e at Fs 24 Hz, Qts 0.42 and 74 liters of Vas, and the \u003cstrong\u003eMP 300 D2.3\u003c\/strong\u003e at Fs 23 Hz, Qts 0.48 and 88 liters. Both are genuinely capable foundations for a sealed 12.\u003c\/p\u003e\n\u003cp\u003eThe cone is a \u003cstrong\u003eV-cone profile\u003c\/strong\u003e pressed from paper pulp with mineral powder injection, the technique Hertz uses on the Mille Legend line, so the diaphragm behaves like a piston rather than flexing at the edge. The surround is high-purity IIR butyl rubber. A \u003cstrong\u003e65mm four-layer CCAW voice coil\u003c\/strong\u003e sits on a vented TIL-P former, driven by a high-density ferrite motor in a six-spoke aluminum alloy basket vented under the spider. Excursion is 17mm linear with 27mm of mechanical travel before damage.\u003c\/p\u003e\n\u003cp\u003eIf you are cross shopping our Hertz cabinets: the Mille Pro MPS series is the shallower line and gets its own cabinets. This page is cut for the Mille Pro MP 300 only.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eNet Volume and Alignment\u003c\/h3\u003e\n\u003cp\u003eThe cabinet holds \u003cstrong\u003e1.512 cubic feet net\u003c\/strong\u003e, from 1.601 cubic feet gross after the brace and the driver's 0.08 cubic feet of displacement (estimated, no manufacturer figure).\u003c\/p\u003e\n\u003cp\u003eHeight here is set by the driver's mounting depth, not by a volume target. The 6.457 inch motor needs 0.75 inch of clearance above it, so the cabinet can go no lower than 8 inches. At that height the wide footprint holds \u003cstrong\u003e1.512 net\u003c\/strong\u003e, more than the 1.10 the standard 30 x 15 box was built to (our solver puts its true net at 1.173). More air lowers Qtc, which is the safe direction: a softer, better damped corner rather than a peakier one.\u003c\/p\u003e\n\u003cp\u003eComputed from Hertz's published Thiele-Small parameters for each coil: \u003cstrong\u003eMP 300 D4.3: Qtc 0.694, Fc 39.6 Hz, F3 40.4 Hz\u003c\/strong\u003e; \u003cstrong\u003eMP 300 D2.3: Qtc 0.839, Fc 40.2 Hz, F3 34.8 Hz\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eHertz recommends 28 liters sealed; this cabinet gives about 43, set by the motor rather than chosen. The effect runs the safe way. The \u003cstrong\u003eD4.3\u003c\/strong\u003e lands just under maximally flat, controlled and even. The \u003cstrong\u003eD2.3\u003c\/strong\u003e, with its higher Qts and larger Vas, keeps more lift near the corner and reaches about 5.6 Hz deeper. Firing down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz.\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\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 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 9.75 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\u003eWindowed U-Brace\u003c\/h4\u003e\n\u003cp\u003eA \u003cstrong\u003ewindowed U-brace\u003c\/strong\u003e dadoed to the shell ties the long 41 inch panels together without taking a meaningful bite out of the airspace.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eSide-Mounted Terminal Cup\u003c\/h4\u003e\n\u003cp\u003eProline X ABS and carbon fiber composite cup with stainless hardware and copper ring terminals, pre-wired in \u003cstrong\u003e12 gauge OFC\u003c\/strong\u003e. Side mounted so it stays accessible with the baffle facing the floor.\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 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\u003eHertz rates the MP 300 at \u003cstrong\u003e600 watts RMS and 1200 watts peak\u003c\/strong\u003e, and sensitivity is \u003cstrong\u003e86 dB at 1W\/1m\u003c\/strong\u003e. Most subwoofers in this category sit in the low to mid 80s, so the MP 300 reaches a given output on less amplifier power, which also reduces thermal stress over long sessions.\u003c\/p\u003e\n\u003cp\u003eBoth versions are dual voice coil, so final impedance is set at the driver: the D2.3 gives 1 ohm in parallel or 4 ohms in series, the D4.3 gives 2 ohms in parallel or 8 in series. Confirm your amplifier is stable at your chosen load before powering the system.\u003c\/p\u003e\n\u003cp\u003eThe enclosure carries a 1 year limited warranty. Bring your own MP 300 D2.3 or D4.3; the driver is 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":47345339990105,"sku":"PO 12-S DFW MP","price":319.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0689\/1389\/files\/PO_12_S_DFW_MP_Front.jpg?v=1790650557","url":"https:\/\/audiointensity.com\/products\/performance-optimized-down-fire-wide-sealed-12-enclosure-hertz-mille-pro-mp-300","provider":"Audio Intensity","version":"1.0","type":"link"}