Performance Optimized Down Fire Wide Sealed 10" Enclosure Focal SUB 25 KXE · Single 10" Sealed enclosure

Because it is only 12 inches deep. The standard Performance Optimized Down Fire platform is 30 wide by 15 deep, and this application needs a cabinet that fits a space three inches shallower than that.

The airspace has to come from somewhere, so the cabinet runs 41 inches long instead of 30 and stands 8.3125 inches tall. If you have 15 inches of depth, the standard cabinet is the pick; if your space is long and shallow, under a rear bench or on a narrow cargo floor, this is the shape that fits.

The standard cabinet is 30 x 15 x 8.27 inches and holds 1.18 cubic feet net. This cabinet is 41 x 12 x 8.3125 and holds 1.300 cubic feet net, 0.120 cubic feet more, because its height is set by the SUB 25 KXE's mounting depth rather than by a volume target. More air means a lower, more damped Qtc, which is the safe direction. The choice is about shape: the standard box needs 15 inches of depth, this one needs 12 inches of depth and 41 inches of run.

The KXE's 6.77 inch mounting depth sets the minimum cabinet height, and the airspace comes with it. At 1.300 cubic feet net: Qtc 0.646 with Fc at 47.2 Hz and a predicted F3 of 52.1 Hz. Below the 0.707 reference, so the rolloff is gentle rather than flat.

Those are anechoic figures. Firing into the floor, the sealed rolloff meets rising cabin gain, so in-car response runs deeper than the numbers above.

Focal rates the SUB 25 KXE at 600 watts RMS and 1200 watts maximum, so target 420 to 600 watts RMS at the final load.

The driver carries two 4 ohm voice coils (3.2 ohms DC each): wire them in parallel for a nominal 2 ohm load or in series for 8 ohms. Confirm your amplifier's minimum stable impedance first.

The cabinet is 8.3125 inches tall in the down fire position, excluding the standoffs. The standoffs hold 1.75 inches under the baffle, so plan around a finished stack of 10.0625 inches on a 41 by 12 inch footprint. Height is set by the KXE's 6.77 inch motor.

Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup, and on a down fire cabinet that keeps the connection accessible with the enclosure installed, since the baffle faces the floor. The cup is our Proline X ABS and carbon fiber composite unit, recessed, with stainless hardware, copper ring terminals, and pre-wired 12 gauge OFC.

V-groove and dado joinery, CNC cut on ShopSabre routers from Langboard Elite MDF. Every panel joint is a machined interlocking groove that mechanically locks the panels before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Corners are square, the Down Fire series standard, with no radii.

The front baffle is a double layer at 1.5 inches, with the outer layer machined as a flush recess so the driver bolts to the inner layer. A windowed U-brace ties the long panels together across the 41 inch span. The baffle ships undrilled with a threaded insert kit because Focal prints no bolt circle. Polyfill is installed as a light wall lining. Assembled and inspected in Tullahoma, Tennessee.

No driver. This is an enclosure only: the cabinet in plush black carpet, one side-mounted pre-wired terminal cup, the polyfill lining in place, the standoffs, and a threaded insert kit with stainless machine screws.

The inserts ship loose on purpose: Focal prints no bolt circle for the SUB 25 KXE, so you set the driver in the recess, mark its holes, drill and press the inserts. The SUB 25 KXE is purchased separately.