Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure Focal SUB 25 KXE · Dual 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 10.5 inches tall, with each driver still in its own chamber. 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 11.23 inches and gives each driver 0.83 cubic feet net. This cabinet is 41 x 12 x 10.5 and gives each driver 0.836 cubic feet net, within 0.006 cubic feet of the standard box. Acoustically they are effectively the same enclosure. 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.

It is the Butterworth volume on Focal's published Fs 38 Hz, Qts 0.52 and Vas 20 liters. At 0.836 cubic feet net per chamber: Qtc 0.706 with Fc at 51.6 Hz and a predicted F3 of 51.7 Hz. If Focal's Vas is really nearer 16 liters, as its moving mass implies, Qtc reads a few hundredths lower.

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 per driver and 1200 watts maximum, so target 420 to 600 watts RMS per driver at the final load.

Each driver has two 4 ohm coils. Wire both drivers identically: each driver in series with the pair in parallel gives 4 ohms, the safe load on any amplifier; all four coils in parallel is 1 ohm and needs an amplifier rated for it; all in series is 16 ohms. Confirm your amplifier's minimum stable impedance first.

The cabinet is 10.5 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 12.25 inches on a 41 by 12 inch footprint.

Side mounted, and there is one cup serving both chambers rather than one per chamber. 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 both baffles face the floor. The cup is our Proline X ABS and carbon fiber composite unit, recessed, with stainless hardware, copper ring terminals, and 12 gauge OFC pre-wired to both driver positions in parallel.

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 both chambers 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 each driver bolts to the inner layer. A full-height bonded 3/4 inch divider separates the chambers and ties the front and rear walls 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 to both positions, 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 pair of SUB 25 KXE is purchased separately.