Performance Optimized Down Fire Sealed 12" Enclosure | Prodigy NB2-12 Single 12" Sealed enclosure

The 12 reaches considerably deeper. This enclosure produces an F3 of 34.6 Hz against the 10 inch cabinet's 43.0 Hz, a difference of more than 8 Hz. That comes from the drivers: the NB2-12D4 has a 28.37 Hz free-air resonance and 55.4 liters of Vas, against 34.3 Hz and 21.1 liters on the NB2-10D4.

The 10 has the slightly better damped alignment at Qtc 0.640 against 0.680, and it stands 7.25 inches tall against this cabinet's 8.6875. Both share the 30 by 15 inch footprint. If you have the vertical clearance and want extension, take the 12.

Yes, and it comes from the driver rather than the cabinet. The NB2-12D4 has a free-air resonance of 28.37 Hz, which is genuinely low for a 400 watt entry-level 12. Most drivers in this bracket sit in the mid 30s, and a sealed enclosure always raises the system corner frequency above the driver's Fs, so a high starting point caps how low the finished system can go.

Combined with 55.4 liters of Vas, this driver has both the low resonance and the compliance to work with. The 34.6 Hz result is among the deepest single-driver figures in the Proline X Down Fire line.

Exactly. Prodigy recommends 1.25 cubic feet net sealed for the NB2-12D4 and that is what this enclosure delivers, after accounting for their published 0.13 cubic foot driver displacement.

That is worth noting because the 10 inch NB2 cabinet cannot match its own recommendation. The 10's mounting depth forces the box larger than Prodigy specifies. On this 12 the target volume requires more internal height than the driver's clearance demands, so the acoustics set the size and the driver fits inside comfortably.

The enclosure has one side-mounted Proline X terminal cup pre-wired in 12 gauge OFC. The NB2-12D4 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 400 watts RMS. Confirm your amplifier is stable at your chosen load and set gains for 300 to 400 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 cargo deck, 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 matters with an 11.2 inch cutout. 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 NB2-12D4. The cutout and mounting depth are cut specifically for this driver.