{"product_id":"performance-optimized-down-fire-sealed-dual-8-enclosure-ampere-audio-aa-2-75-8","title":"Performance Optimized Down Fire Sealed Dual 8\" Enclosure | Ampere Audio AA-2.75 8","description":"\u003cstyle\u003e.df-wrap{font-family:'Helvetica Neue',Arial,sans-serif;line-height:1.75;color:#d6d3d1;max-width:1100px;margin:0 auto;background:#0c0a09}.df-wrap *{box-sizing:border-box}.df-hero{background:linear-gradient(135deg,#0c0a09 0%,#5c3317 100%);padding:54px 36px;text-align:center;color:#fff}.df-hero h2{font-size:2.3em;font-weight:800;text-transform:uppercase;letter-spacing:1.5px;margin:0 0 12px;color:#fff}.df-hero p{font-size:1.1em;font-weight:300;opacity:.93;margin:0 0 22px;color:#d6d3d1}.df-badges{display:flex;justify-content:center;flex-wrap:wrap;gap:10px}.df-badge{background:rgba(184,115,51,.18);border:1px solid #b87333;color:#e8b98d;padding:7px 16px;border-radius:18px;font-size:.8em;font-weight:600}.df-stats{display:flex;flex-wrap:wrap;background:#1c1917}.df-stat{flex:1 1 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class=\"df-wrap\"\u003e\n\u003cdiv class=\"df-hero\"\u003e\n\u003ch2\u003eProline X Performance Optimized Down Fire Dual 8\" Sealed\u003c\/h2\u003e\n\u003cp\u003eCut and tuned for a pair of Ampere Audio AA-2.75 8\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\"\u003e1.05 cu ft Net Total\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eSeparate Chambers\u003c\/span\u003e\u003cspan class=\"df-badge\"\u003eStandoffs Included\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\"\u003e0.53\u003c\/span\u003e\u003cspan class=\"l\"\u003ecu ft net per chamber\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e0.617\u003c\/span\u003e\u003cspan class=\"l\"\u003esystem Qtc per chamber\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e60.4 Hz\u003c\/span\u003e\u003cspan class=\"l\"\u003eF3 rolloff, anechoic\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e7.92 in\u003c\/span\u003e\u003cspan class=\"l\"\u003ecabinet height, excludes standoffs\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\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.\u003c\/td\u003e\n\u003ctd class=\"on\"\u003eA shared 30 by 15 inch platform, with cabinet height as the variable. This build sits on that platform at 7.92 inches tall, the height its 6.42 inch motor needs.\u003c\/td\u003e\n\u003ctd\u003eCompact per driver footprint.\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\"\u003eThreaded insert kit and stainless machine screws included; Ampere prints no bolt circle, so you mark and drill from the driver.\u003c\/td\u003e\n\u003ctd\u003eThreaded 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, full-height divider and 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\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 driver's own 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 Ampere Audio AA-2.75 8\u003c\/h3\u003e\n\u003cp\u003eNothing about this cabinet is generic. The baffle is cut to 7.28 in, Ampere's published cutout, under the 8.66 in frame. The airspace lands on \u003cstrong\u003e0.53 cubic feet net per chamber\u003c\/strong\u003e, the volume the cabinet reaches at the height the 6.42 inch motor requires.\u003c\/p\u003e\n\u003cp\u003eThe AA-2.75 8 is Ampere's 8 inch in the AA-2.75 series: a cast aluminum basket, a 2.5 inch four-layer copper voice coil, a three-layer progressive spider pack and a dual 80 ounce motor, rated 800 watts RMS with 19 mm of one-way excursion, 6.42 inches of mounting depth on an 8.66 inch frame. It sits 6.42 inches deep, which matters on a down fire, where the motor rises into the cabinet. Every Thiele-Small figure comes from Ampere's own published table for the AA-2.75 8, and the table holds together: the moving mass and resonance reproduce the published Vas on a cone area in class for an 8 inch driver. One cell in Ampere's table is wrong: the cone area is printed as 130 square centimeters, but Ampere's own Vas and compliance put it at 200, which is in class for an 8 inch cone, and that figure is used here.\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 rule for dual sealed builds: \u003cstrong\u003etwo fully separate chambers\u003c\/strong\u003e split by a bonded full height 3\/4 inch MDF divider, each driver in its own 0.53 cubic feet with 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 either would have on its own. A full divider removes that entirely. One shared side mounted terminal cup feeds both driver positions, so the cabinet stays a single connection point.\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\u003e0.53 cubic feet net per driver\u003c\/strong\u003e, out of 1.22 gross after the divider and the drivers. Ampere does not publish driver displacement, so an estimated 0.066 cubic feet per driver is taken out of the net figure. The 6.42 inch mounting depth sets this cabinet's minimum height on the 30 by 15 platform, and the airspace comes with it.\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 displacement, not guessed from external dimensions minus wall thickness.\u003c\/p\u003e\u003c\/div\u003e\n\u003cp\u003e0.53 cubic feet net per chamber on Ampere's published figures: the dual 4 ohm reads Qtc 0.617 with resonance at 51.8 Hz and half power at 60.4 Hz. That is a slightly over-damped alignment: a gentle, early rolloff and tight transients rather than a flat top. This cabinet is listed for the AA-2.75 8 dual 4 ohm only. Ampere's dual 2 ohm version reads Qtc 0.56 in the same airspace, too damped to sound right sealed, so it is not offered in this enclosure.\u003c\/p\u003e\n\u003ctable class=\"df-tier\"\u003e\n\u003ctr\u003e\n\u003cth\u003eDriver (per chamber)\u003c\/th\u003e\n\u003cth\u003eSystem Qtc\u003c\/th\u003e\n\u003cth\u003efc\u003c\/th\u003e\n\u003cth\u003eF3\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAA-2.75 8 dual 4 ohm\u003c\/td\u003e\n\u003ctd\u003eQtc 0.617\u003c\/td\u003e\n\u003ctd\u003e51.8 Hz\u003c\/td\u003e\n\u003ctd\u003e60.4 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\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. Corners are square on Down Fire cabinets.\u003c\/p\u003e\n\u003cp\u003eThe cabinet measures \u003cstrong\u003e30.00 inches wide by 15.00 inches deep by 7.92 inches tall, measured in the down fire position and excluding standoffs\u003c\/strong\u003e. Plan the space around the installed height rather than the cabinet height: the standoffs hold 1.75 inches under the baffle, so the finished stack sits near \u003cstrong\u003e9.67 inches\u003c\/strong\u003e.\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 to both driver positions. 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\u003eStandoffs Included\u003c\/h4\u003e\n\u003cp\u003eAmpere publishes no front clearance figure for the AA-2.75 8, so this cabinet uses the Proline X standard \u003cstrong\u003e1.75 inch\u003c\/strong\u003e standoff, shipped with every enclosure and left uninstalled so you can place them to suit your floor. At that height the floor slot is 1.29 times the cone area, enough for the AA-2.75 8.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003eMotor Clearance and Orientation\u003c\/h3\u003e\n\u003cp\u003eThe motors rise off the baffle into the cavity, so on a down fire cabinet the clearance that matters runs to the top panel. The 6.42 inch mounting depth puts the motor 4.92 inches into a 5.67 inch cavity, leaving \u003cstrong\u003e0.75 inches above the motor\u003c\/strong\u003e against a 0.75 inch minimum. Height was set by that clearance, not by the airspace: the volume alone would have allowed a lower box.\u003c\/p\u003e\n\u003cp\u003eAmpere does not publish a position on down firing this driver, and this cabinet makes no claim on their behalf. The feet ship uninstalled, so if you would rather run it front firing or up firing, that is a decision you can make at install time without changing anything about the enclosure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-section\"\u003e\n\u003ch3\u003ePower, Mounting and Warranty\u003c\/h3\u003e\n\u003cp\u003eAmpere rates the AA-2.75 8 at \u003cstrong\u003e800 watts RMS\u003c\/strong\u003e, 1600 watts RMS combined. This cabinet is for the AA-2.75 8 dual 4 ohm; a matched pair should share a coil. A pair of dual 4 ohm drivers lands on 4 ohms with each woofer's coils in series and the woofers in parallel, or 1 ohm with everything in parallel. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for, so series wiring is the safe default. Confirm the load against your amplifier's minimum stable impedance before powering the system.\u003c\/p\u003e\n\u003cp\u003eAmpere prints no bolt circle for the AA-2.75 8, so the baffle ships undrilled with a threaded insert kit and stainless machine screws: set the driver in the recess, mark its holes, drill, press the inserts and bolt it down. The enclosure carries a 1 year limited warranty. Bring your own pair of AA-2.75 8; the drivers are purchased separately.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"df-cta\"\u003e\n\u003ch3\u003eCut for the Driver, Not the Catalog\u003c\/h3\u003e\n\u003cp\u003eBuilt one at a time in Tullahoma, Tennessee, with standoffs and a 1 year limited warranty. Questions on fitment or amplifier matching, call 931-563-5151.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":47379333054553,"sku":"PO 8D-S DF AA275","price":299.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0689\/1389\/files\/PO_8D-S_DF_AA275_Front.jpg?v=1791173462","url":"https:\/\/audiointensity.com\/products\/performance-optimized-down-fire-sealed-dual-8-enclosure-ampere-audio-aa-2-75-8","provider":"Audio Intensity","version":"1.0","type":"link"}