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class=\"df-wrap\"\u003e\n\n\u003cdiv class=\"df-hero\"\u003e\n  \u003ch2\u003eProline X Performance Optimized Down Fire 8\" Ported\u003c\/h2\u003e\n  \u003cp\u003eThe only eight in the ported range, and the smallest cabinet we build\u003c\/p\u003e\n  \u003cdiv class=\"df-badges\"\u003e\n    \u003cspan class=\"df-badge\"\u003e1.05 cu ft net\u003c\/span\u003e\n    \u003cspan class=\"df-badge\"\u003eTuned 34.0 Hz\u003c\/span\u003e\n    \u003cspan class=\"df-badge\"\u003eF3 30.2 Hz\u003c\/span\u003e\n    \u003cspan class=\"df-badge\"\u003eL-wrap slot port\u003c\/span\u003e\n    \u003cspan class=\"df-badge\"\u003eCut for the Image Dynamics ID8 V4\u003c\/span\u003e\n    \u003cspan class=\"df-badge\"\u003eBuilt in Tennessee\u003c\/span\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"df-stats\"\u003e\n  \u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e1.05\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\"\u003e34.0\u003c\/span\u003e\u003cspan class=\"l\"\u003eHz tuning\u003c\/span\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e30.2\u003c\/span\u003e\u003cspan class=\"l\"\u003eHz F3 anechoic\u003c\/span\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"df-stat\"\u003e\n\u003cspan class=\"n\"\u003e15.6\u003c\/span\u003e\u003cspan class=\"l\"\u003esq in port area\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"df-section\"\u003e\n  \u003ch3\u003eWhy this driver is vented at 34.0 Hz\u003c\/h3\u003e\n  \u003cp\u003eEight inch drivers are usually where a ported build stops making sense: too little cone area to move the air, too little compliance to tune low. The ID8 V4 is the exception because of one number. It resonates at 31 Hz free-air, which is lower than most twelves manage, and a motor that reaches that far down can be vented properly rather than as a gesture.\u003c\/p\u003e\n  \u003cp\u003eTuned to 34.0 Hz in 1.04 cubic feet it reaches an anechoic F3 of 30.2 Hz. That is deeper than three of the twelve inch cabinets in this same range, from a driver with less than half their cone area. It is also the smallest box we build ported, at 12.50 inches of external depth, which is the whole reason to want an eight in the first place.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"df-section\"\u003e\n  \u003ch3\u003eThe port is the product\u003c\/h3\u003e\n  \u003cp\u003eA ported cabinet is easy to get wrong and the failure is audible. This one uses an\n  L-wrap slot port: a single folded wall running down the long side of the box past the\n  woofer ring, turning once through a faceted 90 degree bend, and opening through a\n  chamfered corner. One wall, one bend, 27.82 inches of centreline path.\u003c\/p\u003e\n  \u003cp\u003eThe channel is 2.50 inches wide by 6.25 tall, 15.6 square inches, and it exits\n  through a 17.7 square inch mouth. Air leaves at 10.8 metres per second at the tuning\n  frequency, against the 17.0 metre per second threshold where a slot port starts to\n  chuff. The bend is faceted rather than square because the inner corner of a 90 degree\n  turn is where flow separates, and a sharp corner there is what you hear.\u003c\/p\u003e\n  \u003cdiv class=\"df-highlight\"\u003e\n    \u003cp\u003e\u003cstrong\u003eThis enclosure ships dry.\u003c\/strong\u003e Polyfill goes in every sealed Proline X\n    cabinet we build. It does not go in this one. Damping material in a vented box\n    changes the effective volume the port is tuned against, which moves the tuning\n    frequency away from the 34.0 Hz the port length was cut for. Adding it does not make\n    a ported box sound like a bigger ported box; it makes it a mistuned one.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"df-section\"\u003e\n  \u003ch3\u003eRun a subsonic filter\u003c\/h3\u003e\n  \u003cp\u003eThis is not optional advice on a vented enclosure. Below tuning the port stops\n  loading the cone and excursion climbs without limit toward DC, so a 27 Hz high-pass at\n  24 dB per octave is part of the specification rather than a refinement of it. Set it\n  and the same cabinet takes substantially more power for the same cone travel. Leave it\n  out and the driver runs out of suspension on material you cannot hear.\u003c\/p\u003e\n  \u003cp\u003eEvery wattage on the Performance Graphs tab is a mechanical limit, not an electrical\n  one: it is the power at which the cone reaches the end of its linear travel in this\n  box. What the voice coil can dissipate as heat is a separate ceiling set by Image Dynamics, not by\n  the cabinet.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"df-section\"\u003e\n  \u003ch3\u003eCut for this driver, not for a catalogue\u003c\/h3\u003e\n  \u003cdiv class=\"df-grid\"\u003e\n    \u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eMounting\u003c\/h4\u003e\n\u003cp\u003eCut to Image Dynamics's published 7.087 inch cutout with a\n    9.250 inch ring bonded under the baffle. The ring drops into a machined recess so it\n    self-centres, and it roughly doubles the glue area over a butt joint.\u003c\/p\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eThreaded, not screwed\u003c\/h4\u003e\n\u003cp\u003eEight #8-32 hurricane nuts are\n    driven into the ring before it is bonded, so the driver mounts into steel rather than\n    into MDF and survives being unbolted more than once. The ring is cut with sixteen\n    positions so the driver can be clocked to whatever orientation the install needs;\n    eight are fitted.\u003c\/p\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eBraced\u003c\/h4\u003e\n\u003cp\u003eA windowed brace sits between the woofer cutout\n    and the port terminus, 3.13 inches clear of the cutout edge. The window is not weight\n    saving: a solid panel there would split the cavity and turn the cabinet into a\n    bandpass.\u003c\/p\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"df-card\"\u003e\n\u003ch4\u003eJoinery\u003c\/h4\u003e\n\u003cp\u003eV-groove and dado throughout, 0.75 inch\n    material, double-layer 1.5 inch baffle. The walls seat into dados in both the lid and\n    the baffle rather than butting against them.\u003c\/p\u003e\n\u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"df-section\"\u003e\n  \u003ch3\u003ePower, wiring and warranty\u003c\/h3\u003e\n  \u003cp\u003eImage Dynamics rate the ID8 V4 at 150 W RMS. Terminal cup is side mounted, as on every Performance\n  Optimized cabinet. If you are running a dual 2 ohm driver, note that parallel wiring\n  presents 1 ohm, which many amplifiers are not stable into; series at 4 ohm is the safe\n  default unless yours is rated for it.\u003c\/p\u003e\n  \u003cp\u003ePerformance Optimized carries a 1-year warranty. The enclosure is built to order in\n  Tullahoma, Tennessee, and the driver is not included.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"df-cta\"\u003e\n  \u003cp\u003eCut, folded and finished for the Image Dynamics ID8 V4. Nothing on this page is a rule of thumb: the\n  alignment, the port geometry and the power figures all come from Image Dynamics's published\n  parameters run through our own solver.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"Proline X","offers":[{"title":"Default Title","offer_id":44769240088665,"sku":"PO 8-P DF IDv4","price":269.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0689\/1389\/files\/PO_8-P_DF_IDv4_Front.jpg?v=1788273450","url":"https:\/\/audiointensity.com\/products\/performance-optimized-down-fire-ported-8-enclosure-image-dynamics-id8-v4","provider":"Audio Intensity","version":"1.0","type":"link"}