{"product_id":"performance-optimized-down-fire-wide-sealed-dual-10-enclosure-hertz-mille-pro-mps-250","title":"Performance Optimized Down Fire Wide Sealed Dual 10\" Enclosure | Hertz Mille Pro MPS 250","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 10\" Sealed\u003c\/h2\u003e\n\u003cp\u003eUnder rear seat fitment for trucks and SUVs. Cut for a pair of Hertz Mille Pro MPS 250\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\"\u003e12\" Shallow Depth\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eSeparate Chambers\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\"\u003e0.502\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\"\u003e0.677\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc, MPS 250 S2 per chamber\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e48.4 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff, MPS 250 S2\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e6.8125 in\u003c\/span\u003e\u003cspan class=\"l\"\u003ecabinet height\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 Performance Optimized answer to a specific problem: the space under the rear seat of a truck or SUV, or a narrow cargo floor, is \u003cstrong\u003elong and shallow\u003c\/strong\u003e, and the standard 30 by 15 inch Down Fire cabinet will not go in it.\u003c\/p\u003e\n\u003cp\u003eThis cabinet takes the same pair of Hertz MPS 250 and turns the footprint sideways. It runs \u003cstrong\u003e41 inches wide by 12 inches deep by 6.8125 inches tall\u003c\/strong\u003e: 3 inches shallower front to back than the standard 30 x 15 cabinet and 11 inches longer. The airspace given up in depth is recovered along the length, and each driver still gets its own separate chamber.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\u003cp\u003e\u003cstrong\u003eWhich one to choose.\u003c\/strong\u003e If you have 15 inches of depth, the standard 30 x 15 Hertz MPS 250 enclosure is the pick. Choose Down Fire Wide when depth is the limit: under a rear bench or on a narrow cargo floor, with at least 12 inches of depth and 41 inches of run.\u003c\/p\u003e\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 250'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 250s\u003c\/h3\u003e\n\u003cp\u003eBoth baffles are bored to the MPS 250's \u003cstrong\u003e232mm cutout\u003c\/strong\u003e, 9.13 inches, and the cabinet height clears its \u003cstrong\u003e3.25 inch mounting depth\u003c\/strong\u003e. The frame sits on the 12 inch deep baffle.\u003c\/p\u003e\n\u003cp\u003eThe headline number is \u003cstrong\u003e16.8mm of Xmax\u003c\/strong\u003e, exceptional for a shallow mount 10, from a polypropylene cone on a 38mm voice coil with a high density flux ferrite motor, rated 500 watts RMS and 1000 watts peak per driver.\u003c\/p\u003e\n\u003cp\u003eBoth versions are single voice coil, so impedance is fixed by the model: 2 ohms on the MPS 250 S2, 4 ohms on the MPS 250 S4. Note which is which, because it is counterintuitive: on the MPS 250 the S2 is the better damped driver, Qts 0.41 against the S4's 0.48, and the S4 reaches lower with more motor force, 17.3 T·m against 14.7. That pattern reverses on the 12 inch MPS 300.\u003c\/p\u003e\n\u003cp\u003eHertz's published enclosure data reconciles with its own Thiele-Small parameters, which is not true of every manufacturer in this category.\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\u003e0.502 cubic feet net\u003c\/strong\u003e, 1.004 cubic feet across both chambers, from 1.067 cubic feet gross across both, after each driver's 0.021 cubic feet of displacement (0.6 liters, published by Hertz).\u003c\/p\u003e\n\u003cp\u003eComputed from Hertz's published parameters for each model, per coil version and per chamber: \u003cstrong\u003eMPS 250 S2: Qtc 0.677, Fc 46.2 Hz, F3 48.4 Hz. MPS 250 S4: Qtc 0.758, Fc 45.8 Hz, F3 42.9 Hz\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eHeight is the free dimension. With the footprint fixed at 41 by 12, the cabinet height was solved to put each chamber on Hertz's 14.2 liter recommendation, 0.50 cubic feet, then rounded up to the next sixteenth so the airspace lands on the target rather than under it. The 3.25 inch mounting depth leaves 2.81 inches above the motor, so airspace set the height here, not clearance.\u003c\/p\u003e\n\u003cp\u003eThat per driver figure matches Hertz's own sealed recommendation of 14.2 liters. The S2 is the tighter alignment; the S4 reaches lower. Use two of the same model: mismatched drivers between the chambers will not track each other.\u003c\/p\u003e\n\u003cp\u003eThese are anechoic figures. Firing down into the floor, the sealed rolloff meets rising cabin gain, so in-car response extends below them.\u003c\/p\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 eliminates that. Each driver gets its own 0.502 cubic feet and its own polyfill.\u003c\/p\u003e\n\u003cp\u003eOn a long cabinet the divider does structural work as well, tying the front and rear walls together at the center of a 41 inch span.\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 both chambers airtight under sustained pressure cycling. Corners are square on Down Fire cabinets, no radii. Polyfill is installed as a light wall lining, finished in plush black carpet.\u003c\/p\u003e\n\u003cp\u003eThe cabinet measures \u003cstrong\u003e41 inches wide by 12 inches deep by 6.8125 inches tall, measured in the down fire position\u003c\/strong\u003e, excluding feet. No standoffs are required and the cabinet can sit flat; the 1.75 inch feet ship uninstalled if you want them, for an installed height of 8.5625 inches.\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, the outer layer machined as a flush recess so each driver bolts to the inner layer. 8\/32 threaded inserts with stainless machine screws at every mounting location.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eFrame on a 12 Inch Baffle\u003c\/h4\u003e\n\u003cp\u003eBoth \u003cstrong\u003e232mm cutouts\u003c\/strong\u003e sit on the 12 inch deep baffle, and the 3.25 inch motors clear the top panel by 2.81 inches.\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 0.502 cubic feet 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\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- ENCLOSURE PERFORMANCE SLOT --\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003ePower and Wiring\u003c\/h3\u003e\n\u003cp\u003eEach driver is rated \u003cstrong\u003e500 watts RMS\u003c\/strong\u003e and 1000 watts peak, 1000 watts RMS combined. Both models are single voice coil, so there is no coil wiring decision: one side mounted cup feeds both positions in parallel, and the load is set by the model you install, 2 ohms each for the S2, 4 ohms each for the S4. Confirm how the pair resolves against your amplifier's minimum stable load.\u003c\/p\u003e\n\u003cp\u003eFor sealed applications Hertz suggests a 15 Hz subsonic filter at 24 dB per octave and a 70 to 80 Hz low pass.\u003c\/p\u003e\n\u003cp\u003eBring your own pair of MPS 250 S2 or MPS 250 S4, two of the same model; the drivers are purchased separately. The enclosure carries a 1 year limited warranty. Questions on fitment or amplifier matching, call 931-563-5151.\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, built for the space under a rear bench. We build every one to order in Tullahoma, Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":47345069981785,"sku":"PO 10D-S DFW MPS","price":349.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0689\/1389\/files\/PO_10D_S_DFW_MPS_Front.jpg?v=1790693347","url":"https:\/\/audiointensity.com\/products\/performance-optimized-down-fire-wide-sealed-dual-10-enclosure-hertz-mille-pro-mps-250","provider":"Audio Intensity","version":"1.0","type":"link"}