Proline X P12-S DF | Single 12" Sealed Down Fire Subwoofer Enclosure

Proline X | Performance Down Fire A Full Cubic Foot for a 12, Under Seven Inches Tall. A shallow sealed enclosure for a single 12 inch subwoofer. The driver faces down, the top of the cabinet stays flat and usable, and the whole thing stands 8.5 inches tall with the feet installed. Most 12 inch boxes that hold this much air are twice this height. 1.00 CU FT NET 6.75 IN CABINET 6 IN MAX DEPTH DOWN FIRE OR FORWARD FIRE FEET INCLUDED BUILT IN TULLAHOMA, TN Read This First Check Your Driver Depth Maximum driver mounting depth is 6 inches. That is workable for a good number of 12s, but plenty of high excursion 12 inch drivers need 7 inches or more, and those will not fit. Check your driver's published mounting depth against 6 inches before you order. If it needs more, our forward fire P12-S is the better choice. Built Around a Constraint, Not Around a Driver Performance Down Fire enclosures are sized by driver diameter rather than cut for one specific subwoofer. This one takes any 12 inch driver with an 11.13 inch cutout and a mounting depth of 6 inches or less, and gives it 1.00 cubic foot of net airspace. The design brief was height. Getting a full cubic foot into a 6.75 inch cabinet means the footprint has to grow, which is why this enclosure is 29.5 inches wide. Turning the driver toward the floor is what makes the height possible, because the baffle no longer has to face outward into the cargo area. Why Down Fire Turning the driver toward the floor is not a styling decision. It changes what the enclosure does to the space around it and what the space around it can do to the enclosure. Boundary The Floor Is Right There The driver radiates into a hard surface 1.75 inches away. In a trunk or cargo area that reinforcement, combined with cabin gain, is what makes a compact sealed box feel bigger than its airspace. Protection Nothing Lands on the Cone Groceries, tools, luggage, and dogs never touch a surround that is facing down. The most common cause of a damaged subwoofer in a daily driven vehicle is cargo, not power. Packaging A Flat Top You Can Use No basket, no grille, no protrusion. The top of the cabinet is a flat carpeted surface, which in most vehicles means you get the cargo floor back instead of building around a box. Flexibility Not Locked Into One Orientation The feet ship without predrilled holes on purpose. Mount them where your floor wants them, or leave them off entirely and run the cabinet forward firing if your install calls for it. Feet and Clearance What Ships With the Enclosure Four feet come standard with every Performance Down Fire enclosure. There is no upgrade tier and no separate accessory to buy. ABS and carbon fiber composite, machined in house on the same equipment as our terminal cups. 1.75 inches of lift, which sets the working air gap between the baffle and the floor. No predrilled mounting holes, so the enclosure is never locked into a single orientation. Overall height with feet installed: 8.5 inches. Cabinet alone is 6.75 inches. Keep the gap clear. The 1.75 inch space under the baffle is the air path, not empty room. A spare tire, a toolbox, or a folded moving blanket pressed against the opening will choke the output. Down fire systems that sound dead almost always have something jammed underneath them. How It Is Built Cabinet Cut on our ShopSabre CNC from Langboard Elite MDF and assembled with V groove and dado joinery, with internal bracing and a single 0.75 inch baffle. Every panel meets on a machined joint rather than a butt seam, so the cabinet stays rigid and puts its energy into the driver instead of the panels. Mounting Hardware This is a generic enclosure sized by driver diameter, which means we do not know which subwoofer is going into it and cannot machine a bolt pattern for it. The baffle ships as a solid mounting flange and you drill your own mounting holes to match your driver. Threaded inserts are a feature of our Performance Optimized line, where the enclosure is cut for one named subwoofer and the bolt circle is drawn in CAD from the actual driver. The MDF we use is dense. Predrill your mounting holes. Driving screws straight into it without a pilot hole will split the baffle or strip the screw. Wiring and Damping The Proline X ABS and carbon fiber composite terminal cup is side mounted, which keeps the connection accessible with the enclosure sitting on its feet. Pre wired with 12 gauge OFC. Polyfill is installed before the enclosure leaves the shop. Finish Dark gray trunk liner standard, plush black available. The lasered acrylic badge mounts on the front face rather than the woofer face, so it stays visible in the down fire orientation. Fitment The cabinet measures 29.5 inches wide by 14.5 inches deep by 6.75 inches tall, or 8.5 inches tall with the feet installed and the enclosure sitting in the down fire position. Measure the width first. At 29.5 inches this is a full width enclosure, and that width is the price of getting a full cubic foot into a cabinet under 7 inches tall. Height is the spec that makes this design interesting, but width is the spec that decides whether it goes in your vehicle. Enclosure Performance This enclosure is sized by driver diameter rather than cut for one subwoofer, so there is no single response curve for it. What the alignment does depends entirely on the driver you put in, and specifically on its total Q. The table below models three driver profiles across the range you find in 12 inch subwoofers, calculated in 1.00 cubic foot. These are illustrative profiles, not published specifications for any particular subwoofer. Use them to understand the shape of the outcome, then run your own driver's real numbers. Driver Profile (modeled) Qtc fc F3 Result Low Q, Qts 0.40 Fs 30 Hz, Vas 1.30 cu ft 0.607 45.5 Hz 54.2 Hz Overdamped. Rolls off early, thin on the bottom. Mid Q, Qts 0.50 Fs 28 Hz, Vas 1.55 cu ft 0.798 44.7 Hz 40.2 Hz Near textbook. The target for this box. High Q, Qts 0.65 Fs 26 Hz, Vas 1.80 cu ft 1.088 43.5 Hz 33.1 Hz Impact alignment. Lift around 43 Hz, extends lower. -3 dB 0 dB 20 30 50 100 200 Frequency (Hz) +4 -5 -10 -15 Modeled in 1.00 cu ft. Anechoic half-space, no cabin gain. Mid Q, Qts 0.50 Low Q 0.40 and High Q 0.65 What the numbers are telling you. A 1.00 cubic foot sealed box wants a 12 in the middle of the Q range. Drop in a low Q driver and you get an overdamped alignment that gives up real low end. Drop in a high Q driver and you get a lift in the upper bass with deeper extension, which is a legitimate choice if impact is what you want. There is no wrong answer here, but there is a wrong assumption, which is that any 12 will behave the same way in this box. About the Polyfill The 1.00 cubic foot figure is physical net airspace, measured after subtracting bracing and typical driver displacement. It is the number to enter into a modeling program. Polyfill is installed at the correct density before the enclosure ships, which typically makes a sealed box behave as though it were roughly 10 to 15 percent larger, so this cabinet tends to act like 1.10 to 1.15 cubic feet in practice. We quote the physical volume rather than the effective one, so the number you see is the number you can verify. Run your own driver's parameters through the Sealed Box Calculator. Full dimensions, cutout, mounting depth, and hardware details are listed under the Enclosures tab. Shallow, Down Firing, Built in Tennessee. Every Performance Down Fire enclosure is built to order in Tullahoma, Tennessee on our own CNC equipment. Questions on driver depth or whether your subwoofer suits this alignment, call or text 931-563-5151.