{"product_id":"performance-optimized-wedge-sealed-dual-15-enclosure-fi-car-audio-alpha-15","title":"Performance Optimized Wedge Sealed Dual 15\" Enclosure | Fi Car Audio Alpha 15","description":"\u003cdiv class=\"po-wrap\"\u003e\n\u003cstyle\u003e\n.po-wrap{font-family:'Helvetica Neue',Arial,sans-serif;line-height:1.8;color:#1e293b;max-width:1200px;margin:0 auto;background:#fff}\n.po-hero{background:linear-gradient(135deg,#0f172a 0%,#8b5a2b 100%);padding:60px 40px;text-align:center;color:#fff}\n.po-hero .po-title{font-size:2.6em;font-weight:800;text-transform:uppercase;letter-spacing:2px;margin:0 0 10px 0;color:#fff}\n.po-hero .po-subtitle{font-size:1.2em;font-weight:300;opacity:.9;margin:0 0 30px 0}\n.po-badges{display:flex;justify-content:center;flex-wrap:wrap;gap:12px;margin-top:20px}\n.po-badge{background:rgba(184,115,51,.2);border:1px solid #b87333;color:#d99058;padding:8px 20px;border-radius:20px;font-size:.9em;font-weight:600;letter-spacing:.5px}\n.po-section{padding:50px 40px;border-bottom:1px solid #e2e8f0;background:#fff}\n.po-section:nth-child(even){background:#fef3e7}\n.po-section h2{color:#8b5a2b;font-size:2em;font-weight:700;margin:0 0 20px 0;padding-bottom:12px;border-bottom:3px solid #b87333}\n.po-section h3{color:#0f172a;font-size:1.4em;font-weight:600;margin:30px 0 15px 0}\n.po-section p{font-size:1.05em;color:#334155;margin-bottom:18px}\n.po-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;margin:30px 0}\n.po-card{background:#fff;border:1px solid #e2e8f0;border-top:4px solid #b87333;padding:25px;border-radius:4px}\n.po-card h4{color:#8b5a2b;font-size:1.15em;font-weight:700;margin:0 0 12px 0;text-transform:uppercase;letter-spacing:1px}\n.po-card p{font-size:.98em;color:#475569;margin:0}\n.po-highlight{background:#fef3e7;border-left:4px solid #b87333;padding:25px 30px;margin:30px 0;border-radius:4px}\n.po-highlight p{color:#1e293b;margin:0;font-size:1.05em}\n.po-cta{background:linear-gradient(135deg,#0f172a 0%,#8b5a2b 100%);padding:60px 40px;text-align:center;color:#fff}\n.po-cta h2{font-size:2.2em;font-weight:700;margin:0 0 20px 0;color:#fff;border:none;padding:0}\n.po-cta p{font-size:1.15em;opacity:.92;max-width:800px;margin:0 auto 20px auto;color:#fff}\n@media (max-width:768px){.po-hero{padding:40px 20px}.po-hero .po-title{font-size:1.8em}.po-section{padding:30px 20px}.po-section h2{font-size:1.6em}.po-grid{grid-template-columns:1fr}.po-cta{padding:40px 20px}.po-cta h2{font-size:1.6em}}\n\u003c\/style\u003e\n\u003cdiv class=\"po-hero\"\u003e\n\u003cp class=\"po-title\"\u003ePerformance Optimized Wedge | Dual Fi Car Audio Alpha 15\u003c\/p\u003e\n\u003cp class=\"po-subtitle\"\u003eDual 15\" Sealed Wedge Enclosure | Rear-Firing Trunk-Load Design\u003c\/p\u003e\n\u003cdiv class=\"po-badges\"\u003e\n\u003cspan class=\"po-badge\"\u003e1.80 ft3 Net per Chamber\u003c\/span\u003e\u003cspan class=\"po-badge\"\u003e3.97 ft3 Gross\u003c\/span\u003e\u003cspan class=\"po-badge\"\u003eQtc 0.77\u003c\/span\u003e\u003cspan class=\"po-badge\"\u003eTwo Separate Chambers\u003c\/span\u003e\u003cspan class=\"po-badge\"\u003e36.00\" x 18\" x 12.13\/18.68\"\u003c\/span\u003e\u003cspan class=\"po-badge\"\u003eBuilt in Tennessee\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-section\"\u003e\n\u003ch2\u003eA Pair of Fi Car Audio Alpha 15 in a Sealed Wedge\u003c\/h2\u003e\n\u003cp\u003eThe Alpha 15 is the 15 inch from Fi Car Audio's Alpha v1 line: 1000 watts RMS, 17 mm of one-way excursion on 810 square centimeters of cone, and 7.375 inches of mounting depth. Every figure comes from the Thiele-Small and technical tables Fi prints on its Alpha Series product page, including the 0.14 cubic foot driver displacement, and the parameters check against each other: the printed Qts reproduces from Qes and Qms, and Fi's moving mass agrees with its Fs, Vas and cone area.\u003c\/p\u003e\n\u003cdiv class=\"po-highlight\"\u003e\u003cp\u003e1.80 cubic feet net per chamber is Fi's own minimum recommended sealed volume for the Alpha 15. On Fi's figures, Fs 34.7 Hz, Qts 0.52 and Vas 61.00 liters, that is Qtc 0.771 with half power at 47.5 Hz. Fi publishes one parameter set for the Alpha 15 that covers the S1, S2 and S4 single coil versions, so one alignment serves all three. Fi's own recommended sealed range for the Alpha 15 is 1.8 to 3 cubic feet, which reads Qtc 0.77 to 0.68.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-section\"\u003e\n\u003ch2\u003eTwo Fully Separate Chambers\u003c\/h2\u003e\n\u003cp\u003eA bonded full-height 3\/4 inch MDF divider splits the cabinet into two sealed chambers of 1.80 cubic feet net each, so every driver sees exactly the airspace printed on this page. Two drivers sharing one volume load each other; the divider removes that, and each chamber carries its own polyfill.\u003c\/p\u003e\n\u003cp\u003eThe cabinet is 36.00 inches wide, 18 tall, 12.13 inches deep at the top and 18.68 at the base. One shared side-mounted terminal cup feeds both driver positions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-section\"\u003e\n\u003ch2\u003eTrunk-Load Wedge Design Explained\u003c\/h2\u003e\n\u003cp\u003eThe drivers mount on the vertical trunk-lid-side face and fire rearward into the trunk cavity.\u003c\/p\u003e\n\u003cdiv class=\"po-grid\"\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003eSeat-Side Face Matches Seat Lean\u003c\/h4\u003e\n\u003cp\u003eAngled face matches the roughly 20 degree factory seat lean.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003eTrunk-Lid-Side Face Fires the Woofer\u003c\/h4\u003e\n\u003cp\u003eVertical baffle, cone firing rearward into the trunk cavity.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003eTrunk Cavity Loading\u003c\/h4\u003e\n\u003cp\u003eThe trunk acts as an acoustic extension for a smoother presentation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003ePreserves Trunk Cargo Space\u003c\/h4\u003e\n\u003cp\u003eThe wedge tucks against the seat back and the space in front stays usable.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-section\"\u003e\n\u003ch2\u003eEngineered for a pair of Fi Car Audio Alpha 15\u003c\/h2\u003e\n\u003cp\u003eHalf power lands at 47.5 Hz anechoic, before any cabin gain. Above Qtc 0.707 the response carries a small lift near 51 Hz before the rolloff, and F3 sits below fc. Fi publishes the driver displacement, 0.14 cubic feet, and it is taken out of the net figure.\u003c\/p\u003e\n\u003ch3\u003eAlignment Numbers (Per Chamber)\u003c\/h3\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\u003eAlpha 15 S1, S2 or S4\u003c\/td\u003e\n\u003ctd\u003eQtc 0.771\u003c\/td\u003e\n\u003ctd\u003e51.4 Hz\u003c\/td\u003e\n\u003ctd\u003e47.5 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch3\u003eMounting Geometry\u003c\/h3\u003e\n\u003cp\u003eThe baffle is cut to 13.875 in, Fi's published cutout, under the 15.5 in frame. The rear panel rakes 20 degrees, so the cavity deepens from 12.13 in at the top to 18.68 in at the base, and the 7.375 in motor clears it with 4.65 in to spare. Fi prints no bolt circle for the Alpha 15, 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.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-section\"\u003e\n\u003ch2\u003eWhat the Numbers Rest On\u003c\/h2\u003e\n\u003cdiv class=\"po-grid\"\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003eLangboard Elite MDF\u003c\/h4\u003e\n\u003cp\u003ePremium 3\/4 in MDF throughout.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003eV-Groove and Dado Joinery\u003c\/h4\u003e\n\u003cp\u003eCNC cut V-grooves at every panel intersection, sides and divider seated in dados.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003eDouble-Layer 1.5\" Front Baffle\u003c\/h4\u003e\n\u003cp\u003eTwo bonded 3\/4 in MDF sheets at the driver face, the outer layer machined as a flush recess.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-card\"\u003e\n\u003ch4\u003eFi's Published Parameters\u003c\/h4\u003e\n\u003cp\u003eFs 34.7 Hz, Qts 0.52, Qes 0.56, Qms 8.10, Vas 61.00 L, Sd 810 cm2, Cms 0.0663 mm\/N, Mms 326 g, Bl 10.0 \/ 14.1 \/ 20.2 N\/A (S1 \/ S2 \/ S4), Re 0.8 \/ 1.6 \/ 3.3 ohms, sensitivity 88.5 dB 1W\/1m.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-section\"\u003e\n\u003ch2\u003eWiring a pair of Fi Car Audio Alpha 15 to Your Amplifier\u003c\/h2\u003e\n\u003cp\u003eA pair lands on 0.5 ohm parallel or 2 ohms series with S1 coils, 1 ohm parallel or 4 ohms series with S2, and 2 ohms parallel or 8 ohms series with S4. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for; series wiring is the safe default. Confirm the final load against your amplifier's minimum stable impedance before powering the system.\u003c\/p\u003e\n\u003cp\u003ePower handling is 1000 watts RMS per driver, 2000 across the pair. Aim for roughly 700 to 1000 watts per driver at the impedance you wire.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-section\"\u003e\n\u003ch2\u003eBuilt in Tennessee, Backed by Audio Intensity\u003c\/h2\u003e\n\u003cp\u003eCut and assembled in Tullahoma, Tennessee on our own CNC equipment. Finished in plush black carpet with the gloss black acrylic baffle insert, one shared pre-wired terminal cup, 12 gauge OFC to both driver positions. Polyfill wall lining installed. Threaded insert kit and stainless machine screws in the box. 1 year limited warranty. Enclosure only, the drivers are purchased separately. Call or text 931-563-5151.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"po-cta\"\u003e\n\u003ch2\u003eDual Fi Car Audio Alpha 15: Cut for the Driver\u003c\/h2\u003e\n\u003cp\u003e1.80 cubic feet net per chamber at Qtc 0.771, F3 47.5 Hz, cut direct fit and built to order in Tennessee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Black","offer_id":47368499986521,"sku":"PO 15D-S W FI ALPHA BB","price":499.99,"currency_code":"USD","in_stock":true},{"title":"None","offer_id":47368500019289,"sku":"PO 15D-S W FI ALPHA B","price":479.99,"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_64d932a3-af6f-41cf-8f3f-a52d58125f41.jpg?v=1790975107","url":"https:\/\/audiointensity.com\/products\/performance-optimized-wedge-sealed-dual-15-enclosure-fi-car-audio-alpha-15","provider":"Audio Intensity","version":"1.0","type":"link"}