Performance Optimized Down Fire Wide Sealed 12" Shallow Sub Enclosure Prodigy NB3-12 · Single 12" Sealed enclosure

Because it trades length for depth and height. The standard Performance Optimized Down Fire platform is 30 wide by 15 deep; this one is 14 deep, 1 inch shallower, and 41 long. Spreading the airspace along 11 more inches lets the cabinet stand 6.4375 inches tall instead of 7.625.

Fourteen inches of depth is the practical minimum, since a 12 inch frame needs about 13 inches of baffle. If your space is long and low rather than deep or tall, this is the shape that fits.

Same driver, different shape. The standard cabinet is 30 by 15 by 7.625 inches and holds 1.02 cubic feet net. This cabinet is 41 by 14 by 6.4375 inches and holds 1.028 cubic feet net.

The airspace is effectively the same, so the driver behaves the same way in either. Choose the standard box when length is limited; choose this one when height or depth is the limit and you have 41 inches of run.

At 1.028 cubic feet net the NB3-12D4 lands at Qtc 0.689, Fc 51.4 Hz and a predicted anechoic F3 of 52.8 Hz, computed from Prodigy's published Fs 36.2 Hz, Qts 0.485 and Vas 29.665 liters.

That is effectively the maximally flat sealed alignment. A vehicle cabin adds rising gain below roughly 60 Hz, so firing into the floor, in-car response extends below the anechoic figure.

One side-mounted Proline X terminal cup, pre-wired in 12 gauge OFC. The NB3-12D4 is dual 4 ohm, so wire the coils in parallel for 2 ohms or in series for 8 ohms at the driver.

Prodigy rates it at 800 watts RMS continuous. Target 600 to 800 watts RMS and confirm your amplifier is stable at the load you wire.

Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup, whether standard, wedge or down fire, which keeps the connection accessible with the baffle facing 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, long 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 locks the panels before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. The front baffle is a 1.5 inch double layer, the outer layer machined as a flush recess around the 10.875 inch cutout.

A windowed U-brace stiffens the long panels, and polyfill is installed as a light wall lining. Do not add more fill; packing a sealed box makes it act larger and moves the alignment off the 1.028 cubic feet it was built to. Assembled and inspected in Tullahoma, Tennessee.

No. This listing is for the enclosure only. Bring your own Prodigy NB3-12D4, which is a dual 4 ohm driver. The cutout and mounting depth are direct fit.