Performance Optimized Down Fire Ported 12" Enclosure | Prodigy NB3-12

Prodigy quote an EBP of 58.6, which lands in the transition band where a driver will take either load. That is not a reason to default to sealed. Vented at 35 the NB3-12 gives up nothing in flatness and gains real output through 30 to 45 Hz, and because tuning sits close to Fs the cone is barely moving where the port is working hardest. Tuning is chosen for in-car response rather than for an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz, so a box tuned very low reinforces a region the cabin is already reinforcing and leaves 40 to 60 Hz thin. The solver optimises flatness across 25 to 60 Hz, which is where kick and bass fundamentals actually live.

No, and that is deliberate. Every sealed Proline X enclosure ships with polyfill pre-installed. A ported one must not: damping material changes the effective volume the port is tuned against and moves tuning away from the 35.0 Hz this port was cut for. Do not add any.

Yes. Below tuning a vented box stops loading the cone and excursion runs away toward DC. Set a high-pass at 28 Hz, 24 dB per octave. With it the cabinet takes substantially more power for the same cone travel; without it the driver reaches its mechanical limit on content you cannot hear. On a sealed build a subsonic filter is an improvement. Here it is required equipment.

Prodigy rate the NB3-12 at 800 W RMS and that is the thermal ceiling. The figures on the Performance Graphs tab are something different: they are mechanical limits, the power at which the cone runs out of linear travel in this specific cabinet. Where the mechanical figure sits above the driver's rating, heat is what stops you, not travel. Final wired impedance and amplifier output are separate questions again.

Below roughly 25 Hz, yes. A sealed cabinet rolls off gently into the subsonic region where a vented one falls away steeply once it is under tuning, so if the content you are chasing lives that low, sealed reaches further down. Through 25 to 60 Hz this alignment is the louder of the two for the same power. The Performance Graphs tab plots both, at the same net volume, so the alignment is the only variable.

It is a slot port formed by one folded wall: a leg down the long side of the cabinet past the woofer ring, one faceted 90 degree bend, and a leg across the end opening through a chamfered corner. 27.78 inches of centreline path, 21.9 square inches of channel. One wall and one bend rather than a serpentine's three walls and three turns, which means less wall area inside the box, fewer joints to leak and one place for flow to separate instead of three.

V-groove and dado joinery in 0.75 inch Langboard Elite MDF with a double-layer 1.5 inch baffle. The driver mounts to a 13.250 inch ring bonded under the baffle in a machined recess, carrying eight #8-32 hurricane nuts so it threads into steel rather than MDF. A windowed brace sits 3.41 inches clear of the cutout edge and 2.22 inches clear of the port terminus; the window is not weight saving, a solid panel there would split the cavity and make the box a bandpass. Walls seat into dados in both the lid and the baffle. Square corners, plush black carpet, side-mounted terminal cup.

No. This is an enclosure only, cut and folded for the Prodigy NB3-12 specifically: the cutout, mounting depth, displacement and alignment are all taken from Prodigy's published parameters for this driver. It is not a universal box with a 12 inch hole in it. Bring your own driver.