Performance Optimized Down Fire Sealed 10" Enclosure | Prodigy NB2-10 Single 10" Sealed enclosure

Because the driver's mounting depth sets the minimum cabinet height. The NB2-10D4 mounts 5.625 inches deep. Our double baffle recovers 0.75 inches of that, since the outer layer is a flush recess and the driver bolts to the inner layer, and a 3/8 inch milled relief behind the magnet recovers a little more. Even so, with half an inch of clearance behind the motor the minimum internal height is 5 inches, which works out to 0.96 cubic feet net on this footprint. A 0.65 cubic foot cabinet physically cannot contain this driver.

The result is better than the target. At 0.65 net the system would sit near Qtc 0.72. At 0.96 it lands at 0.640, which is more damped, has lower group delay, and reaches about a hertz deeper. The fitment constraint improved the alignment.

Qtc describes how a sealed system behaves near its corner frequency. The textbook reference is 0.707, called maximally flat, which gives the flattest anechoic response. Below that the system is more damped: the rolloff slope is gentler, group delay is lower, and the transient response is tighter, at the cost of a slightly higher corner frequency.

At 0.640 this enclosure sits just under the flat reference. In practice that means clean, controlled bass with no overhang, and a gradual rolloff that integrates well with the rising cabin gain of a vehicle. It is the lowest Qtc of any enclosure in the Proline X Down Fire line.

Depth is the main difference. The NB3-10 is a shallow-mount driver at 3.00 inches, and its Down Fire cabinet stands 6.25 inches tall. The NB2-10D4 mounts 5.625 inches and this cabinet stands 7.25 inches.

The NB2 is the better performer if you have the room. It has more excursion at 14mm against the NB3's 11mm, a lower free-air resonance at 34.3 Hz against 36.4 Hz, and this cabinet reaches a 43 Hz F3 with a Qtc of 0.640 where the NB3 lands at 68 Hz and 0.526. Choose the NB3 only when the last inch of vertical clearance genuinely matters.

The enclosure has one side-mounted Proline X terminal cup pre-wired in 12 gauge OFC. The NB2-10D4 is dual 4-ohm, so you set the final load at the driver: wire the two coils in parallel for a 2 ohm load, or in series for 8 ohms. Most single-driver builds run the 2 ohm configuration.

Prodigy rates this driver at 350 watts RMS. Confirm your amplifier is stable at your chosen load and set gains for 250 to 350 watts.

Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup regardless of alignment, whether standard, wedge, or down fire. On this cabinet that keeps the connection fully accessible with the enclosure in its installed position, 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.

Down Fire cabinets are built with square corners as a series standard. The 3 inch top down corner radius used on other Proline X alignments does not apply here. A down fire box is a low, wide platform that sits flat against a floor or under a seat, and square corners maximize usable internal volume for a given footprint while keeping the cabinet stable on its mounting surface.

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.

The front baffle is a double layer at 1.5 inches, two bonded 3/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3/4 inch of internal clearance for a deep driver. A 3/8 inch relief is milled into the opposite panel behind the magnet. Perimeter cross-bracing and pre-installed polyfill complete the build. Assembled and inspected in Tullahoma, Tennessee.

No. This listing is for the enclosure only. Bring your own Prodigy NB2-10D4. The cutout, mounting depth and magnet clearance are all cut specifically for this driver.