{"title":"Hertz Subwoofer Boxes and Enclosures","description":null,"products":[{"product_id":"performance-optimized-down-fire-sealed-10-enclosure-hertz-mille-pro-mps-250","title":"Performance Optimized Down Fire Sealed 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 10\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut and tuned for the Hertz Mille Pro MPS 250\u003c\/p\u003e\n\u003cdiv class=\"df-badges\"\u003e\n\u003cspan class=\"df-badge\"\u003eV-Groove and Dado\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eLangboard Elite MDF\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e0.51 cu ft Net\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eAmong The Shortest In The Line\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\"\u003e0.51\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\"\u003e0.754\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc, S4\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e42.9 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff, S4\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e4.9375 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\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, with cabinet height as the variable. A few drivers need a wider or deeper platform.\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, 1.5 inch, outer layer machined as a flush recess.\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 airspace, the cutout and the cabinet height 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 the MPS 250\u003c\/h3\u003e\n\u003cp\u003eNothing about this cabinet is generic. The baffle is bored to the Hertz \u003cstrong\u003e232mm cutout\u003c\/strong\u003e, which is 9.13 inches, and the internal height is set by the driver's \u003cstrong\u003e3.25 inch mounting depth\u003c\/strong\u003e. The finished cabinet stands \u003cstrong\u003e4.9375 inches tall\u003c\/strong\u003e on a 30 by 15 inch footprint, measured in the down fire position. That is one of the shortest cabinets in the Proline X Down Fire line, and it fits under seats where almost nothing else will go.\u003c\/p\u003e\n\u003cp\u003eThe headline number on this driver is \u003cstrong\u003e16.8mm of Xmax\u003c\/strong\u003e, which is exceptional for a shallow mount 10. It comes from a polypropylene cone on a 38mm voice coil with a high density flux ferrite motor, rated 500 watts RMS and 1000 watts peak. Hertz includes a mesh grille in the box that can be rotated 90 degrees or removed entirely.\u003c\/p\u003e\n\u003cp\u003eBoth coil options are single voice coil, so impedance is fixed by the model you buy: 2 ohms on the \u003cstrong\u003eMPS 250 S2\u003c\/strong\u003e, 4 ohms on the \u003cstrong\u003eMPS 250 S4\u003c\/strong\u003e. There is no wiring decision at the driver. Hertz publishes its Thiele-Small measured with coils in parallel and states that Fs, Vas and Qts are unchanged in series wiring, with only Re, Le and BL moving, so one cabinet is correct either way.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eNet Volume, Not Gross\u003c\/h3\u003e\n\u003cp\u003eWe build this cabinet at \u003cstrong\u003e0.51 cubic feet net\u003c\/strong\u003e out of 0.58 cubic feet gross, which matches Hertz's own sealed recommendation of 14.2 liters. There is no argument with the manufacturer to have here: the volume they ask for is the volume the cabinet holds after panel thickness, bracing and driver displacement are accounted for.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\u003cp\u003e\u003cstrong\u003eTrue net, not marketing net.\u003c\/strong\u003e Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.\u003c\/p\u003e\u003c\/div\u003e\n\u003cp\u003eNote which coil is which here, because it is counterintuitive. On the MPS 250 the \u003cstrong\u003eS2 is the better damped driver\u003c\/strong\u003e, with a free-air Qts of 0.41 against the S4's 0.48. In this volume the S2 lands at \u003cstrong\u003eQtc 0.673 with F3 at 48.4 Hz\u003c\/strong\u003e and the S4 at \u003cstrong\u003eQtc 0.754 with F3 at 42.9 Hz\u003c\/strong\u003e. So the S2 is the tighter alignment and the S4 reaches lower and carries more motor force, 17.3 T·m against 14.7. That pattern reverses on the 12 inch MPS 300, where the S4 is the tighter of the pair, so do not assume it carries across sizes.\u003c\/p\u003e\n\u003cp\u003eWorth saying plainly: \u003cstrong\u003eHertz's published enclosure data reconciles with its own T\/S parameters.\u003c\/strong\u003e Running their Qts and Vas through standard sealed box math at their recommended volume lands within 0.03 of the Qtc they print. That is not true of every manufacturer in this category, and it means the numbers on this page and the numbers in the Hertz manual are the same numbers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eDown Fire 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\u003cdiv class=\"df-grid\"\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eDouble Baffle, Flush Recess\u003c\/h4\u003e\n\u003cp\u003eThe front baffle is \u003cstrong\u003e1.5 inches\u003c\/strong\u003e, two bonded 3\/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3\/4 inch of internal clearance, which matters on a cabinet under five inches tall.\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\u003ePerimeter Cross-Bracing\u003c\/h4\u003e\n\u003cp\u003ePerimeter cross-bracing ties the long spans together on a wide, shallow cabinet where panel area is the main resonance risk. Polyfill is pre-installed and the driver mounts into 8\/32 threaded inserts with stainless machine screws included.\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\u003eDown Firing Into the Floor\u003c\/h3\u003e\n\u003cp\u003eThe driver fires downward into the floor and the cabinet couples to the surface it sits on. No standoffs are required; the cabinet sits flat. The sealed rolloff meets rising cabin gain below 60 Hz, so in-car response extends well below the anechoic figures quoted above.\u003c\/p\u003e\n\u003cp\u003eFor sealed applications Hertz suggests a \u003cstrong\u003e15 Hz subsonic filter at 24 dB per octave\u003c\/strong\u003e and a 70 to 80 Hz low pass, also at 24 dB per octave. Those are the manufacturer's own recommended settings for this driver.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003ePower and Warranty\u003c\/h3\u003e\n\u003cp\u003eThe MPS 250 is rated \u003cstrong\u003e500 watts RMS and 1000 watts peak\u003c\/strong\u003e on a 38mm voice coil. Since both models are single voice coil, the load your amplifier sees is decided when you choose the S2 or the S4. Check what your amplifier is stable into before you order the driver.\u003c\/p\u003e\n\u003cp\u003eThe enclosure carries a 1 year limited warranty. Bring your own MPS 250 S2 or MPS 250 S4; 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\u003eHertz asked for 14.2 liters, so that is what this cabinet holds, in the shortest package that will take the driver. Machined, assembled and inspected one at a time in Tullahoma, Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44540397977689,"sku":"PO 10-S DF MPS","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_d3392418-bfcf-4041-8081-2882ffb8915f.jpg?v=1787113026"},{"product_id":"performance-optimized-down-fire-sealed-12-enclosure-hertz-mille-pro-mps-300","title":"Performance Optimized Down Fire Sealed 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 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10px}.df-legend{display:flex;flex-wrap:wrap;gap:12px;margin-top:10px}.df-legend-item{display:flex;align-items:center;gap:6px;font-size:12px;color:#a8a29e}.df-sw{width:22px;height:3px;border-radius:2px;display:inline-block}.df-note{background:#292524;border:1px solid #44403c;border-radius:8px;padding:14px 16px;margin-top:10px}.df-note p{margin:0;color:#d6d3d1;font-size:13.5px;line-height:1.6}.df-link{color:#d99058;text-decoration:underline}.df-cta{background:linear-gradient(135deg,#0c0a09 0%,#5c3317 100%);padding:40px 36px;text-align:center;color:#fff}.df-cta h3{color:#fff;font-size:1.4em;margin:0 0 10px;border:none;padding:0}.df-cta p{opacity:.92;margin:0 auto;max-width:640px;color:#d6d3d1}.df-tier{overflow-x:auto;margin:18px 0;border:1px solid #44403c;border-radius:8px}.df-tier table{width:100%;border-collapse:collapse;min-width:660px}.df-tier th{background:#0c0a09;color:#a8a29e;font-size:.74em;text-transform:uppercase;letter-spacing:.6px;padding:12px 14px;text-align:left;border-bottom:1px solid #44403c;font-weight:700}.df-tier th.on{background:#3d2412;color:#e8b98d}.df-tier td{padding:11px 14px;border-bottom:1px solid #292524;color:#a8a29e;font-size:.88em;vertical-align:top;line-height:1.55}.df-tier td.a{color:#d6d3d1;font-weight:700;background:#1c1917;width:19%}.df-tier 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 12\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut and tuned for the Hertz Mille Pro MPS 300\u003c\/p\u003e\n\u003cdiv class=\"df-badges\"\u003e\n\u003cspan class=\"df-badge\"\u003eV-Groove and Dado\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eLangboard Elite MDF\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e0.80 cu ft Net\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e16.8mm Xmax\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\"\u003e0.80\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\"\u003e0.812\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc, S4\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e39.5 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff, S4\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e6.375 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\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, with cabinet height as the variable. A few drivers need a wider or deeper platform.\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, 1.5 inch, outer layer machined as a flush recess.\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 airspace, the cutout and the cabinet height 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 the MPS 300\u003c\/h3\u003e\n\u003cp\u003eNothing about this cabinet is generic. The baffle is bored to the Hertz \u003cstrong\u003e283mm cutout\u003c\/strong\u003e, which is 11.14 inches, and the internal height is set by the driver's \u003cstrong\u003e3.46 inch mounting depth\u003c\/strong\u003e. The result is a full 12 in a cabinet that stands \u003cstrong\u003e6.375 inches tall\u003c\/strong\u003e on a 30 by 15 inch footprint, measured in the down fire position.\u003c\/p\u003e\n\u003cp\u003eThe MPS 300 carries \u003cstrong\u003e16.8mm of Xmax\u003c\/strong\u003e, an unusually high figure for a shallow driver, on a polypropylene cone with a 38mm voice coil and a high density flux ferrite motor. It is rated 500 watts RMS and 1000 watts peak. Hertz includes a mesh grille in the box that can be rotated 90 degrees or removed entirely.\u003c\/p\u003e\n\u003cp\u003eWhat makes this driver reach is the suspension: a \u003cstrong\u003e24 Hz free-air resonance on the S2 paired with 64.9 liters of Vas\u003c\/strong\u003e, and 23 Hz with 62.1 liters on the S4. Both models are single voice coil, so impedance is fixed by the model you buy, 2 ohms on the \u003cstrong\u003eMPS 300 S2\u003c\/strong\u003e and 4 ohms on the \u003cstrong\u003eMPS 300 S4\u003c\/strong\u003e. Hertz publishes its Thiele-Small measured with coils in parallel and states that Fs, Vas and Qts are unchanged in series wiring, with only Re, Le and BL moving, so one cabinet is correct either way.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eNet Volume, Not Gross\u003c\/h3\u003e\n\u003cp\u003eWe build this cabinet at \u003cstrong\u003e0.80 cubic feet net\u003c\/strong\u003e out of 0.89 cubic feet gross, which matches Hertz's own sealed recommendation of 22.7 liters. The volume they ask for is the volume the cabinet holds after panel thickness, bracing and driver displacement are accounted for.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\u003cp\u003e\u003cstrong\u003eTrue net, not marketing net.\u003c\/strong\u003e Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.\u003c\/p\u003e\u003c\/div\u003e\n\u003cp\u003ePay attention to the coil 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, with a free-air Qts of 0.42 against the S2's 0.51, and it carries far more motor force at 18.7 T·m against 12.3. In this volume the \u003cstrong\u003eS4 lands at Qtc 0.812 with F3 at 39.5 Hz\u003c\/strong\u003e and the \u003cstrong\u003eS2 at Qtc 1.003 with F3 at 37.1 Hz\u003c\/strong\u003e. So the S4 is the controlled alignment and the S2 reaches about 2.4 Hz deeper with a modest lift at the corner. Both are usable; if your amplifier is happy either way, take the S4 for accuracy and the S2 for extension.\u003c\/p\u003e\n\u003cp\u003eThat \u003cstrong\u003e37.1 Hz F3 on the S2 is among the deepest in the Proline X Down Fire line\u003c\/strong\u003e, which is unusual for a cabinet this short. Worth saying plainly: \u003cstrong\u003eHertz's published enclosure data reconciles with its own T\/S parameters.\u003c\/strong\u003e Running their Qts and Vas through standard sealed box math at their recommended volume lands within 0.2 Hz of the corner frequency they print on both variants. That is not true of every manufacturer in this category.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eDown Fire 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\u003cdiv class=\"df-grid\"\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eDouble Baffle, Flush Recess\u003c\/h4\u003e\n\u003cp\u003eThe front baffle is \u003cstrong\u003e1.5 inches\u003c\/strong\u003e, two bonded 3\/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3\/4 inch of internal clearance, which is what lets a 12 live in a 6.375 inch cabinet.\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\u003ePerimeter Cross-Bracing\u003c\/h4\u003e\n\u003cp\u003ePerimeter cross-bracing ties the long spans together on a wide, shallow cabinet where panel area is the main resonance risk. Polyfill is pre-installed and the driver mounts into 8\/32 threaded inserts with stainless machine screws included.\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\u003eDown Firing Into the Floor\u003c\/h3\u003e\n\u003cp\u003eThe driver fires downward into the floor and the cabinet couples to the surface it sits on. No standoffs are required; the cabinet sits flat. The sealed rolloff meets rising cabin gain below 60 Hz, so in-car response extends well below the anechoic figures quoted above.\u003c\/p\u003e\n\u003cp\u003eFor sealed applications Hertz suggests a \u003cstrong\u003e15 Hz subsonic filter at 24 dB per octave\u003c\/strong\u003e and a 70 to 80 Hz low pass, also at 24 dB per octave. Those are the manufacturer's own recommended settings for this driver.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003ePower and Warranty\u003c\/h3\u003e\n\u003cp\u003eThe MPS 300 is rated \u003cstrong\u003e500 watts RMS and 1000 watts peak\u003c\/strong\u003e on a 38mm voice coil. Since both models are single voice coil, the load your amplifier sees is decided when you choose the S2 or the S4. Check what your amplifier is stable into before you order the driver.\u003c\/p\u003e\n\u003cp\u003eThe enclosure carries a 1 year limited warranty. Bring your own MPS 300 S2 or MPS 300 S4; 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\u003eHertz asked for 22.7 liters, so that is what this cabinet holds, in the shortest package that will take a 12 inch driver. Machined, assembled and inspected one at a time in Tullahoma, Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44540398043225,"sku":"PO 12-S DF MPS","price":269.99,"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_c9c57507-5385-43a5-ba1b-3c721041263f.jpg?v=1787113026"},{"product_id":"performance-optimized-down-fire-sealed-dual-10-enclosure-hertz-mille-pro-mps-250","title":"Performance Optimized Down Fire 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 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14px;text-align:left;border-bottom:1px solid #44403c;font-weight:700}.df-tier th.on{background:#3d2412;color:#e8b98d}.df-tier td{padding:11px 14px;border-bottom:1px solid #292524;color:#a8a29e;font-size:.88em;vertical-align:top;line-height:1.55}.df-tier td.a{color:#d6d3d1;font-weight:700;background:#1c1917;width:19%}.df-tier 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 Dual 10\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut and tuned for a pair of Hertz Mille Pro MPS 250\u003c\/p\u003e\n\u003cdiv class=\"df-badges\"\u003e\n\u003cspan class=\"df-badge\"\u003eV-Groove and Dado\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eLangboard Elite MDF\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e1.00 cu ft Net\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\"\u003e1.00\u003c\/span\u003e\u003cspan class=\"l\"\u003ecu ft net total\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e0.754\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc, S4\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e42.9 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e7.6875 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\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, with cabinet height as the variable. A few drivers need a wider or deeper platform.\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, 1.5 inch, outer layer machined as a flush recess.\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 airspace, the cutout and the cabinet height 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 internal height is set by the driver's \u003cstrong\u003e3.25 inch mounting depth\u003c\/strong\u003e. The cabinet stands \u003cstrong\u003e7.6875 inches tall\u003c\/strong\u003e on the same 30 by 15 inch footprint as the single, and delivers roughly 6 dB more maximum output than one driver in the same alignment.\u003c\/p\u003e\n\u003cp\u003eEach MPS 250 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. That is exceptional travel for a shallow 10, and two of them move a serious amount of air from a cabinet under 8 inches tall. 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\u003eEach driver is sold as the MPS 250 S2 at 2 ohms or the MPS 250 S4 at 4 ohms, both single voice coil. Use two of the same model. Mismatched drivers between the two chambers will not track each other.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eNet Volume, Not Gross\u003c\/h3\u003e\n\u003cp\u003eEach chamber is built at \u003cstrong\u003e0.50 cubic feet net per driver\u003c\/strong\u003e, \u003cstrong\u003e1.00 cubic foot net total\u003c\/strong\u003e, out of a 1.14 cubic foot gross cavity. That per driver figure matches Hertz's own sealed recommendation of 14.2 liters, so each chamber lands on the same alignment as the single driver cabinet: Qtc 0.673 with F3 at 48.4 Hz on the S2, or Qtc 0.754 with F3 at 42.9 Hz on the S4.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\u003cp\u003e\u003cstrong\u003eTrue net, not marketing net.\u003c\/strong\u003e Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.\u003c\/p\u003e\u003c\/div\u003e\n\u003cp\u003eNote which coil is which, because it is counterintuitive. On the MPS 250 the \u003cstrong\u003eS2 is the better damped driver\u003c\/strong\u003e, with a free air Qts of 0.41 against the S4's 0.48. The S4 reaches lower and carries more motor force, 17.3 T·m against 14.7. That pattern reverses on the 12 inch MPS 300, so do not assume it carries across sizes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eTwo Chambers, Not One Volume\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, giving each driver its own dedicated airspace and its own polyfill.\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 entirely, and each MPS 250 sees exactly the 0.50 cubic feet Hertz specifies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eDown Fire Construction\u003c\/h3\u003e\n\u003cp\u003eCut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3\/4 inch MDF. 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.\u003c\/p\u003e\n\u003cdiv class=\"df-grid\"\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eDouble Baffle, Flush Recess\u003c\/h4\u003e\n\u003cp\u003eBoth front baffles are \u003cstrong\u003e1.5 inches\u003c\/strong\u003e, two bonded 3\/4 inch sheets, with the outer layer machined as a flush recess so each driver bolts to the inner layer. That recovers 3\/4 inch of internal clearance at each position.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eSide-Mounted Terminal Cup\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eOne\u003c\/strong\u003e Proline X ABS and carbon fiber composite cup with stainless hardware and copper ring terminals serves both chambers, pre-wired in \u003cstrong\u003e12 gauge OFC\u003c\/strong\u003e to both driver positions in parallel. Side mounted so it stays accessible with the baffles facing the floor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eSeparate Chambers\u003c\/h4\u003e\n\u003cp\u003eA \u003cstrong\u003efull height bonded 3\/4 inch MDF divider\u003c\/strong\u003e splits the cabinet into two sealed chambers of 0.50 cubic feet net each. Perimeter cross-bracing, polyfill in each chamber, and two sets of 8\/32 threaded inserts with stainless machine screws.\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; your final load is set by which model you install and how the pair resolves at the amplifier. Confirm that against your amplifier's minimum stable load before powering up.\u003c\/p\u003e\n\u003cp\u003eHertz publishes Thiele-Small measured with coils in parallel and states that Fs, Vas and Qts are identical in series wiring, and their published enclosure data reconciles with their own T\/S parameters, which is not true of every manufacturer in this category. Firing down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz. Hertz suggests a 15 Hz subsonic filter at 24 dB per octave and a 70 to 80 Hz low pass for sealed applications.\u003c\/p\u003e\n\u003cp\u003eThe enclosure carries a 1 year limited warranty. Bring your own pair of MPS 250 S2 or MPS 250 S4; the drivers are purchased separately. Assembled and inspected in Tullahoma, Tennessee.\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\u003eOne cutout, one mounting depth, one published airspace per chamber. Every Performance Optimized cabinet is machined to a single driver's numbers and built one at a time in Tullahoma, Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44540398108761,"sku":"PO 10D-S DF MPS","price":299.99,"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_61921df5-44e0-4ea2-8cc1-aa1337adbbca.jpg?v=1787113027"},{"product_id":"performance-optimized-down-fire-sealed-dual-12-enclosure-hertz-mille-pro-mps-300","title":"Performance Optimized Down Fire 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 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th{background:#0c0a09;color:#a8a29e;font-size:.74em;text-transform:uppercase;letter-spacing:.6px;padding:12px 14px;text-align:left;border-bottom:1px solid #44403c;font-weight:700}.df-tier th.on{background:#3d2412;color:#e8b98d}.df-tier td{padding:11px 14px;border-bottom:1px solid #292524;color:#a8a29e;font-size:.88em;vertical-align:top;line-height:1.55}.df-tier td.a{color:#d6d3d1;font-weight:700;background:#1c1917;width:19%}.df-tier 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 Dual 12\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut and tuned for a pair of Hertz Mille Pro MPS 300\u003c\/p\u003e\n\u003cdiv class=\"df-badges\"\u003e\n\u003cspan class=\"df-badge\"\u003eV-Groove and Dado\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eLangboard Elite MDF\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e1.60 cu ft Net\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\"\u003e1.60\u003c\/span\u003e\u003cspan class=\"l\"\u003ecu ft net total\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e0.812\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc, S4\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e39.5 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e10.75 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\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, with cabinet height as the variable. A few drivers need a wider or deeper platform.\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, 1.5 inch, outer layer machined as a flush recess.\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 airspace, the cutout and the cabinet height 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 baffles are bored to the MPS 300's \u003cstrong\u003e283mm cutout\u003c\/strong\u003e, 11.14 inches, and the internal height is set by the driver's \u003cstrong\u003e3.46 inch mounting depth\u003c\/strong\u003e. The cabinet stands \u003cstrong\u003e10.75 inches tall\u003c\/strong\u003e on the standard 30 by 15 inch footprint, and delivers roughly 6 dB more maximum output than a single driver in the same alignment.\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\u003eAt 37.1 Hz per driver on the S2, this is among the deepest reaching enclosures in the Proline X Down Fire line, and here you get it twice. That depth comes from a \u003cstrong\u003e24 Hz free air resonance paired with a 64.9 liter Vas\u003c\/strong\u003e in a driver that mounts in 3.46 inches. 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 the two chambers will not track each other.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eNet Volume, Not Gross\u003c\/h3\u003e\n\u003cp\u003eEach chamber is built at \u003cstrong\u003e0.80 cubic feet net per driver\u003c\/strong\u003e, \u003cstrong\u003e1.60 cubic feet net total\u003c\/strong\u003e, out of a 1.78 cubic foot gross cavity. That per driver figure matches Hertz's own sealed recommendation of 22.7 liters, so each chamber lands on the same alignment as the single driver cabinet: Qtc 1.003 with F3 at 37.1 Hz on the S2, or Qtc 0.812 with F3 at 39.5 Hz on the S4.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\u003cp\u003e\u003cstrong\u003eTrue net, not marketing net.\u003c\/strong\u003e Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.\u003c\/p\u003e\u003c\/div\u003e\n\u003cp\u003ePay attention to the coil choice, because \u003cstrong\u003eit reverses from the 10 inch model\u003c\/strong\u003e. On the MPS 300 the S4 is the better damped driver, with a free air Qts of 0.42 against the S2's 0.51, and it carries far more motor force, 18.7 T·m against 12.3. The S4 gives the more controlled alignment; the S2 reaches roughly 2.4 Hz lower. On the MPS 250 the pattern is the opposite. Same series, reversed between sizes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eTwo Chambers, Not One Volume\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, giving each driver its own dedicated airspace and its own polyfill.\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 entirely, and each MPS 300 sees exactly the 0.80 cubic feet Hertz specifies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eDown Fire Construction\u003c\/h3\u003e\n\u003cp\u003eCut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3\/4 inch MDF. 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.\u003c\/p\u003e\n\u003cp\u003eBe realistic about size. At 10.75 inches this is the tallest cabinet in the Down Fire program. It is a cargo floor, rear wall or behind the bench build rather than an under seat one. The 30 by 15 inch footprint is unchanged, so it takes no more floor area than any other Down Fire cabinet, it simply stands taller to give each driver its full 0.80 cubic feet. Measure your vertical clearance before ordering.\u003c\/p\u003e\n\u003cdiv class=\"df-grid\"\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eDouble Baffle, Flush Recess\u003c\/h4\u003e\n\u003cp\u003eBoth front baffles are \u003cstrong\u003e1.5 inches\u003c\/strong\u003e, two bonded 3\/4 inch sheets, with the outer layer machined as a flush recess so each driver bolts to the inner layer. That recovers 3\/4 inch of internal clearance at each position, and it matters with two 11 inch cutouts in one cabinet.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eSide-Mounted Terminal Cup\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eOne\u003c\/strong\u003e Proline X ABS and carbon fiber composite cup with stainless hardware and copper ring terminals serves both chambers, pre-wired in \u003cstrong\u003e12 gauge OFC\u003c\/strong\u003e to both driver positions in parallel. Side mounted so it stays accessible with the baffles facing the floor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eSeparate Chambers\u003c\/h4\u003e\n\u003cp\u003eA \u003cstrong\u003efull height bonded 3\/4 inch MDF divider\u003c\/strong\u003e splits the cabinet into two sealed chambers of 0.80 cubic feet net each. Perimeter cross-bracing, polyfill in each chamber, and two sets of 8\/32 threaded inserts with stainless machine screws.\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; your final load is set by which model you install and how the pair resolves at the amplifier. Confirm that against your amplifier's minimum stable load before powering up.\u003c\/p\u003e\n\u003cp\u003eHertz publishes Thiele-Small measured with coils in parallel and states that Fs, Vas and Qts are identical in series wiring, and their published enclosure data reconciles with their own T\/S parameters, which is not true of every manufacturer in this category. Firing down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz. Hertz suggests a 15 Hz subsonic filter at 24 dB per octave and a 70 to 80 Hz low pass for sealed applications.\u003c\/p\u003e\n\u003cp\u003eThe enclosure carries a 1 year limited warranty. Bring your own pair of MPS 300 S2 or MPS 300 S4; the drivers are purchased separately. Assembled and inspected in Tullahoma, Tennessee.\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\u003eOne cutout, one mounting depth, one published airspace per chamber. Every Performance Optimized cabinet is machined to a single driver's numbers and built one at a time in Tullahoma, Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44540398174297,"sku":"PO 12D-S DF MPS","price":299.99,"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_4188b18c-b0d1-464e-911e-6ad64cff1957.jpg?v=1787113028"},{"product_id":"performance-optimized-down-fire-sealed-10-enclosure-hertz-mille-pro-mp-250","title":"Performance Optimized Down Fire Sealed 10\" Enclosure | Hertz Mille Pro MP 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 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th{background:#0c0a09;color:#a8a29e;font-size:.74em;text-transform:uppercase;letter-spacing:.6px;padding:12px 14px;text-align:left;border-bottom:1px solid #44403c;font-weight:700}.df-tier th.on{background:#3d2412;color:#e8b98d}.df-tier td{padding:11px 14px;border-bottom:1px solid #292524;color:#a8a29e;font-size:.88em;vertical-align:top;line-height:1.55}.df-tier td.a{color:#d6d3d1;font-weight:700;background:#1c1917;width:19%}.df-tier 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 10\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut and tuned for the Hertz Mille Pro MP 250\u003c\/p\u003e\n\u003cdiv class=\"df-badges\"\u003e\n\u003cspan class=\"df-badge\"\u003eV-Groove and Dado\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eLangboard Elite MDF\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e1.00 cu ft Net\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eMilled Magnet Relief\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\"\u003e1.00\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\"\u003e0.741\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e39.4 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e7.4375 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\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, with cabinet height as the variable. A few drivers need a wider or deeper platform.\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, 1.5 inch, outer layer machined as a flush recess.\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 airspace, the cutout and the cabinet height all come from the Hertz Mille Pro MP 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 the Hertz MP 250\u003c\/h3\u003e\n\u003cp\u003eNothing about this cabinet is generic. The baffle is bored to the MP 250's \u003cstrong\u003e236mm cutout\u003c\/strong\u003e, the internal height is set by its \u003cstrong\u003e5.80 inch mounting depth\u003c\/strong\u003e, and the airspace is what that geometry leaves once the driver is in place. Overall frame diameter is 268mm, and the driver bolts to 8\/32 threaded inserts with stainless machine screws included.\u003c\/p\u003e\n\u003cp\u003eThe construction is classic Hertz. The cone is a \u003cstrong\u003eV-cone profile\u003c\/strong\u003e pressed from paper pulp with mineral powder injection, the same technique used on the flagship Mille Legend line, so the diaphragm resists bending and behaves like a piston instead of flexing at the outer edge as excursion rises. The surround is high-purity IIR butyl rubber. Motor work is a \u003cstrong\u003e65mm four-layer CCAW voice coil\u003c\/strong\u003e on a vented TIL-P former, carried in a six-spoke aluminum alloy basket with vents under the spider.\u003c\/p\u003e\n\u003cp\u003eExcursion is \u003cstrong\u003e17mm linear with 27mm of mechanical travel\u003c\/strong\u003e before damage, so there is real headroom above the linear figure. Sensitivity is 83.4 dB at 1W\/1m, which is on the low side for a 10 inch driver, so plan on giving it power rather than expecting output from a small amplifier. One clarification if you are cross shopping: the Mille Pro MPS 250 is the shallow mount driver and gets its own shorter cabinet. This page is cut for the deeper, higher excursion MP 250 only.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eNet Volume, Not Gross\u003c\/h3\u003e\n\u003cp\u003eWe build this cabinet at \u003cstrong\u003e1.00 cubic feet net\u003c\/strong\u003e against 1.11 gross, and Hertz publishes 17 liters, or 0.60 cubic feet, as the recommended sealed volume. The gap is driver geometry, not preference. At 5.80 inches the MP 250 is a deep driver, and it displaces \u003cstrong\u003e3.2 liters, 0.113 cubic feet\u003c\/strong\u003e, of airspace on its own. Even with the flush recess outer baffle layer and a milled magnet relief recovering clearance, the minimum internal height works out to 5.1875 inches. A 0.60 cubic foot cabinet cannot physically contain this driver.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\u003cp\u003e\u003cstrong\u003eTrue net, not marketing net.\u003c\/strong\u003e Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.\u003c\/p\u003e\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eThe constraint improves the alignment.\u003c\/strong\u003e Computed from Hertz's published Fs of 30 Hz, Qts of 0.54 and Vas of 25 liters, this cabinet lands at \u003cstrong\u003eQtc 0.741 with Fc at 41.2 Hz and a predicted F3 of 39.4 Hz\u003c\/strong\u003e. At Hertz's own 0.60 cubic feet the same driver computes to Qtc 0.849 with F3 at 40.6 Hz. The larger box is better damped, holds transients tighter, and reaches marginally deeper.\u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003eMP 250 D2.3\u003c\/strong\u003e and \u003cstrong\u003eMP 250 D4.3\u003c\/strong\u003e share the same Thiele-Small set, so the alignment above applies to both. The only difference is coil impedance, which you set at the driver, not a difference in enclosure behavior.\u003c\/p\u003e\n\u003cp\u003eFiring down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz, so in-car response extends below the anechoic figure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eDown Fire Construction\u003c\/h3\u003e\n\u003cp\u003eCut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3\/4 inch MDF. Every panel joint is a machined interlocking groove that mechanically locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Perimeter cross-bracing ties the panels together and polyfill is pre-installed. Corners are square on Down Fire cabinets.\u003c\/p\u003e\n\u003cp\u003eExternal dimensions are \u003cstrong\u003e30 inches wide by 15 inches deep by 7.4375 inches tall, measured in the down fire position\u003c\/strong\u003e. The driver fires down into the floor, and the finished weight is 30 pounds.\u003c\/p\u003e\n\u003cdiv class=\"df-grid\"\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eDouble Baffle, Flush Recess\u003c\/h4\u003e\n\u003cp\u003eThe front baffle is \u003cstrong\u003e1.5 inches\u003c\/strong\u003e, two bonded 3\/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3\/4 inch of internal clearance.\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\u003eMilled Magnet Relief\u003c\/h4\u003e\n\u003cp\u003eA \u003cstrong\u003e3\/8 inch deep relief\u003c\/strong\u003e is machined into the panel opposite the baffle, directly behind the magnet. That buys back clearance for the MP 250's motor without adding cabinet height.\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 250 at \u003cstrong\u003e600 watts RMS and 1200 watts peak\u003c\/strong\u003e. Both 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 Hertz Mille Pro MP 250 D2.3 or MP 250 D4.3; the driver is purchased separately. The cutout, mounting depth and magnet clearance are all cut for that driver specifically.\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\u003eOne driver, one set of published parameters, one cabinet machined to match them. Built one at a time in Tullahoma, Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44540886319193,"sku":"PO 10-S DF MP","price":259.99,"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_c90b35b7-5e68-4b03-a374-fce9247b4795.jpg?v=1787122825"},{"product_id":"performance-optimized-down-fire-sealed-12-enclosure-hertz-mille-pro-mp-300","title":"Performance Optimized Down Fire 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 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10px}.df-legend{display:flex;flex-wrap:wrap;gap:12px;margin-top:10px}.df-legend-item{display:flex;align-items:center;gap:6px;font-size:12px;color:#a8a29e}.df-sw{width:22px;height:3px;border-radius:2px;display:inline-block}.df-note{background:#292524;border:1px solid #44403c;border-radius:8px;padding:14px 16px;margin-top:10px}.df-note p{margin:0;color:#d6d3d1;font-size:13.5px;line-height:1.6}.df-link{color:#d99058;text-decoration:underline}.df-cta{background:linear-gradient(135deg,#0c0a09 0%,#5c3317 100%);padding:40px 36px;text-align:center;color:#fff}.df-cta h3{color:#fff;font-size:1.4em;margin:0 0 10px;border:none;padding:0}.df-cta p{opacity:.92;margin:0 auto;max-width:640px;color:#d6d3d1}.df-tier{overflow-x:auto;margin:18px 0;border:1px solid #44403c;border-radius:8px}.df-tier table{width:100%;border-collapse:collapse;min-width:660px}.df-tier th{background:#0c0a09;color:#a8a29e;font-size:.74em;text-transform:uppercase;letter-spacing:.6px;padding:12px 14px;text-align:left;border-bottom:1px solid #44403c;font-weight:700}.df-tier th.on{background:#3d2412;color:#e8b98d}.df-tier td{padding:11px 14px;border-bottom:1px solid #292524;color:#a8a29e;font-size:.88em;vertical-align:top;line-height:1.55}.df-tier td.a{color:#d6d3d1;font-weight:700;background:#1c1917;width:19%}.df-tier 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 12\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut and tuned for the Hertz Mille Pro MP 300\u003c\/p\u003e\n\u003cdiv class=\"df-badges\"\u003e\n\u003cspan class=\"df-badge\"\u003eV-Groove and Dado\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eLangboard Elite MDF\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003e1.10 cu ft Net\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\"\u003e1.10\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\"\u003e0.771\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e40.7 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e8.125 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\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, with cabinet height as the variable. A few drivers need a wider or deeper platform.\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, 1.5 inch, outer layer machined as a flush recess.\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 airspace, the cutout and the cabinet height 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\u003eNothing about this cabinet is generic. The 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\u003e6.46 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 actually pull against.\u003c\/p\u003e\n\u003cp\u003eThe driver underneath is a genuinely capable foundation for a sealed 12: a \u003cstrong\u003e24 Hz free-air resonance\u003c\/strong\u003e, 74 liters of Vas, and a Qts of 0.42 that is low enough to reach a properly damped sealed alignment. Effective cone diameter is 260mm.\u003c\/p\u003e\n\u003cp\u003eThe construction is classic Hertz. The cone is a \u003cstrong\u003eV-cone profile\u003c\/strong\u003e pressed from paper pulp with mineral powder injection, the same technique used on the flagship Mille Legend line, so the diaphragm behaves like a piston rather than flexing at the edge under load. 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 compact high-density ferrite motor with a BL of 12 T\/m, all carried 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\u003eOne clarification if 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, Not Gross\u003c\/h3\u003e\n\u003cp\u003eWe build this cabinet at \u003cstrong\u003e1.10 cubic feet net\u003c\/strong\u003e against 1.26 gross. Hertz publishes 28 liters, or 0.99 cubic feet, as the recommended sealed volume, and this cabinet runs slightly larger because the driver's 6.46 inch mounting depth sets the floor on internal height. With the flush recess outer baffle layer and a milled magnet relief both recovering clearance, the minimum internal height still works out to 5.875 inches.\u003c\/p\u003e\n\u003cdiv class=\"df-highlight\"\u003e\u003cp\u003e\u003cstrong\u003eTrue net, not marketing net.\u003c\/strong\u003e Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.\u003c\/p\u003e\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eThe extra volume lands in your favor.\u003c\/strong\u003e Computed from Hertz's published Fs of 24 Hz, Qts of 0.42 and Vas of 74 liters, this cabinet reaches \u003cstrong\u003eQtc 0.771 with Fc at 44.1 Hz and a predicted F3 of 40.7 Hz\u003c\/strong\u003e. Hertz publishes Qtc 0.82 and Fb 48 Hz at their own 28 liter figure. Better damped, gentler corner, no meaningful loss anywhere.\u003c\/p\u003e\n\u003cp\u003eWorth saying plainly: Hertz's published enclosure data reconciles with their own Thiele-Small parameters, which is less common in this category than it should be. Running their numbers independently at their own 28 liters produces Qtc 0.80 against a published 0.82.\u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003eMP 300 D2.3\u003c\/strong\u003e and \u003cstrong\u003eMP 300 D4.3\u003c\/strong\u003e share the same Thiele-Small set, so the alignment above applies to both. The difference is coil impedance, which you set at the driver, not a difference in enclosure behavior.\u003c\/p\u003e\n\u003cp\u003eFiring down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz, so in-car response extends below the anechoic figure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eDown Fire Construction\u003c\/h3\u003e\n\u003cp\u003eCut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3\/4 inch MDF. Every panel joint is a machined interlocking groove that mechanically locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Perimeter cross-bracing ties the panels together and polyfill is pre-installed. Corners are square on Down Fire cabinets.\u003c\/p\u003e\n\u003cp\u003eExternal dimensions are \u003cstrong\u003e30 inches wide by 15 inches deep by 8.125 inches tall, measured in the down fire position\u003c\/strong\u003e. The driver fires down into the floor, and the finished weight is 34 pounds.\u003c\/p\u003e\n\u003cdiv class=\"df-grid\"\u003e\n\u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eDouble Baffle, Flush Recess\u003c\/h4\u003e\n\u003cp\u003eThe front baffle is \u003cstrong\u003e1.5 inches\u003c\/strong\u003e, two bonded 3\/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3\/4 inch of internal clearance, which matters with an 11.30 inch cutout.\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\u003eMilled Magnet Relief\u003c\/h4\u003e\n\u003cp\u003eA \u003cstrong\u003e3\/8 inch deep relief\u003c\/strong\u003e is machined into the panel opposite the baffle, directly behind the magnet, so the MP 300's motor gets its clearance without adding cabinet height.\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, among the most efficient drivers in the Down Fire line. 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 Hertz Mille Pro MP 300 D2.3 or MP 300 D4.3; the driver is purchased separately. The cutout, mounting depth and magnet clearance are all cut for that driver specifically.\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\u003eOne driver, one set of published parameters, one cabinet machined to match them. Built one at a time in Tullahoma, Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44540886548569,"sku":"PO 12-S DF MP","price":269.99,"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_155e556c-8cd2-44e8-bfb9-9a3df4c04e93.jpg?v=1787122826"}],"url":"https:\/\/audiointensity.com\/collections\/hertz-subwoofer-box.oembed","provider":"Audio Intensity","version":"1.0","type":"link"}