Proline X PO 12-P W NB2 ported wedge, front baffle with gloss black insert and pre-wired leads, 29.5 by 15.5 inches.Proline X PO 12-P W NB2 ported wedge, side profile with recessed terminal cup, 14.39 inch base, 15.5 inches tall.

Performance Optimized · Datasheet

Performance Optimized Wedge Ported 12" Enclosure | Prodigy NB2-12 Single 12" Ported enclosure

Net volume
1.43 Cubic Feet
Tuning
32.5 Hz
Max mounting depth
6.750 Inches (Prodigy Spec)
Cutout
11.200 Inches (Prodigy Spec)
External dimensions
29.50 Inches W × 15.50 Inches H × 8.75 Inches / 14.39 Inches D
Front baffle
Vertical Baffle - Driver Fires Rearward Into The Trunk
Buy at Audio Intensity
  • Alignment: 1.43 cu ft net vented at 32.5 Hz. F3 32.5 Hz anechoic, 1.32 dB passband ripple
  • Driver: Prodigy NB2-12 D4, 400 W RMS, 14.0 mm Xmax, 28.37 Hz Fs
  • Build: Rear-firing wedge, 20 degree rear rake, V-groove and dado joinery, triangular side-exit slot port with a 1/2" rounded mouth, double 1.5" baffle, side-mounted terminal cup
  • Cabinet: 29.50" W x 15.50" H x 14.39" D at base tapering to 8.75" D at top, 16.9 sq in port, ships dry

Technical specifications

SeriesProline X Performance Optimized Wedge
Driver-Specific FitmentProdigy NB2-12 D4
Enclosure TypePorted | Rear-Firing Trunk Wedge
Baffle ConfigurationVertical Baffle - Driver Fires Rearward Into The Trunk
Wedge Angle20 Degrees On The Rear (Seat-Side) Panel
External Width29.50 Inches
External Height15.50 Inches
Top Depth8.75 Inches
Base Depth14.39 Inches
Internal Volume (Gross)1.87 Cubic Feet
Internal Volume (Net After Displacement)1.43 Cubic Feet
Port TypeTriangular Slot | Bottom-Rear Corner | Straight, No Bend | Side Exit
Port GeometryIsosceles, 6.00 Inch Legs, 16.9 Square Inches, 23.35 Inches Long, Side Mouth
Port Tuning (Fb)32.5 Hz
Port MouthTriangle Through Side A, 1/2 In Roundover On All Three Edges, 27.7 Square Inches At The Face
Port ThroatOpen Far End, 4.40 In Gap To Side B, 3/8 In Roundover On The Panel End
Port Air Velocity18.6 m/s In The Channel, 11.4 m/s At The Flared Mouth (17.0 m/s Chuff Threshold)
Predicted F332.5 Hz (Anechoic)
Passband Ripple1.32 dB (Anechoic)
Subsonic Filter26 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs28.37 Hz
Driver Qts0.457
Driver Qes0.522
Driver Vas55.392 Liters / 1.956 Cubic Feet
Driver Sd522.6 Square Centimeters
Driver Mms216.27 g
Driver BL21.27
Driver Re6.2 Ohm
Driver Xmax14mm (One-Way at 70% BL)
Excursion Design BasisDerated To 11.9mm For Alignment - Prodigy Publishes At 70% BL
Driver Displacement0.13 Cubic Feet (Published by Prodigy)
Driver Power Handling400 Watts RMS
Driver Overall Diameter12.500 Inches (Prodigy Spec)
Mounting Depth Required6.750 Inches (Prodigy Spec)
Cutout Diameter11.200 Inches (Prodigy Spec)
MaterialLangboard Elite 3/4" MDF
ConstructionShopSabre CNC / Two Windowed C Braces At The Third Points, Seated On The Port Panel
JoineryV-Groove and Dado (CNC-Cut)
Front Baffle ConstructionDouble-Layer 1.5" MDF | Cosmetic Front Layer Routed For The Acrylic Insert
Mounting HardwareThreaded Inserts At Every Mounting Location | Stainless Steel Machine Screws Included
Terminal CupProline X ABS/Carbon Fiber Composite | Side Mounted, Opposite The Port | 12g OFC Pre-Wired
DampingNone - Ships Dry. Polyfill Detunes A Ported Enclosure
Recommended Power280-400 Watts RMS (Prodigy Rated: 400W RMS)
Carpet FinishPlush Black
Weight49 lb
Bundle OptionsEnclosure Only (Bring Your Own Prodigy NB2-12)
Warranty1-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA

Performance in this enclosure

Net airspace
1.43
cu ft
Tuning
32.5
Hz · Fb
Half power
32.5
Hz · F3, anechoic
Xmax at
2194
W RMS · 26 Hz subsonic
With NO filter
355
W RMS · unfiltered
Port
11.4
m/s at the mouth

01Is this driver right for a ported box?

Efficiency bandwidth product places the motor before anything else is decided.

EBP = Fs ÷ Qes = 54.3
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 EBP 54.3
NB2-12 D4 · EBP 54.3
Between 50 and 100 a driver takes either load, and the choice becomes one of priorities rather than of physics. The NB2-12 D4 reads 54.3. Ported buys output and low-end reach around tuning; sealed buys a shallower rolloff below it. This cabinet takes the first trade.

02What the box does to it

1.43 cu ft net against a 55.4 L Vas, vented at 32.5 Hz.

Fb = 32.5 Hz  ·  F3 = 32.5 Hz  ·  passband ripple 1.32 dB
20 30 50 70 100 150 200 +6 +0 −6 −12 −18 −24 FREQUENCY · Hz LEVEL · dB −3 dB Fb 32.5
NB2-12 D4 · Fb 32.5 Hz, F3 32.5 Hz
Anechoic, before any cabin gain, with the 26 Hz subsonic filter already applied. The vent takes over below 32 Hz and the cone stops doing the work there, which is what holds travel down at the bottom of the passband.

03Perceived Ported vs Sealed

This cabinet, 1.43 cu ft net vented at 32.5 Hz, against the 1.25 cu ft sealed Down Fire we build for this driver (PO 12-S DF NB2).

Ported Fb 32.5 Hz  ·  the 1.25 cu ft sealed box runs Qtc 0.73, Fc 45 Hz
20 30 50 70 100 150 200 +6 +0 −6 −12 −18 −24 FREQUENCY · Hz LEVEL · dB +4.1 dB at 39 Hz
Ported · this cabinet, 1.43 cu ft, Fb 32.5 HzSealed Down Fire we build, 1.25 cu ft, Qtc 0.73
Shaded blue is where the ported alignment is louder for the same power, orange where the sealed one is. The sealed curve is the 1.25 cu ft sealed Down Fire we build for this driver (PO 12-S DF NB2), not this cabinet with the port blocked: two different boxes, because that is the choice a buyer actually has. Across 25 to 60 Hz the vent is worth 4.1 dB at its widest and 3.2 dB on average. This is the anechoic picture, which is not what you hear in a car.

04Real World Ported vs Sealed

The same two boxes with cabin gain applied, 45 Hz corner, 18 dB ceiling.

Flatness across 25–60 Hz: ported 1.7 dB spread, the 1.25 cu ft sealed box 2.3 dB
20 30 50 70 100 150 200 +6 +0 −6 −12 −18 −24 FREQUENCY · Hz LEVEL · dB +4.1 dB at 39 Hz
Ported, in-car · 1.7 dB spreadSealed Down Fire we build, 1.25 cu ft, in-car · 2.3 dB spread
Cabin gain lifts both boxes by the same amount, so the gap between them does not change: what changes is the shape each one ends up with. A car pressurises below roughly 45 Hz, which fills in the sealed box's shallower rolloff and over-drives it where the ported box is already flat. Across 25 to 60 Hz, the band kick and bass fundamentals occupy, this alignment holds 1.7 dB of spread against 2.3 dB for the 1.25 cu ft sealed Down Fire we build for this driver (PO 12-S DF NB2). Flatter is the whole point of tuning this high. Note where the curves cross. Below about 22 Hz the sealed alignment becomes the louder of the two and stays louder all the way down, by up to 1.2 dB: a sealed box rolls off gently into the subsonic region where a vented one falls away steeply once it is below tuning and the vent stops contributing. If the content you are chasing lives below 22 Hz, a sealed alignment reaches further down than this one does. Cabin gain here is a house assumption, not a measurement of your vehicle.

05The watts that reach Xmax (in this enclosure)

Travel scales with the square root of power, so there is one wattage that puts the cone exactly on NB2-12's published 14.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.

PXmax = 2194 W with a 26 Hz subsonic  ·  355 W with none  →  the filter is worth 6.2×
20 30 50 70 100 150 200 0 4 8 12 16 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 14.0 mm design limit 11.9 mm · 70% BL derated 2194 W reaches Xmax here
2194 W · subsonic at 26 Hz, 24 dB/oct355 W · no subsonic filterXmax 14.0 mm one-way, published
Each trace touches the limit and no further, because each is drawn at the exact power that puts the cone on 14.0 mm. With a 26 Hz subsonic that takes 2194 W, reached first at 47 Hz. Take the filter away and the same cabinet reaches 14.0 mm on 355 W — the filter is worth 6.2× the safe power. A vent unloads the cone below tuning, so there is nothing holding it once the box stops loading: on a sealed build a subsonic filter is an improvement, here it is required equipment. The unfiltered trace is still rising where this chart stops at 20 Hz, so treat 355 W as a bound rather than a floor. Every wattage on this page is a MECHANICAL limit, not an electrical one. It is the power at which the cone runs out of linear travel in this cabinet, and nothing more. What the voice coil can dissipate as heat is a separate ceiling set by the driver, not by the box — NB2-12 rate this one at 400 W RMS, and that is the number that binds first here: heat stops you before travel does, so treat 400 W as the ceiling and the travel figures above as headroom. Final wired impedance, amplifier output and how long you hold the level are all electrical questions this graph does not answer. The dashed line at 11.9 mm is the figure the cabinet was actually designed against: NB2-12 publish this Xmax on a 70% BL basis, and we derate it before sizing the port so the alignment carries margin against an optimistic spec rather than sitting right on it.

Installer's take

Prodigy do not publish Sd for this driver. I derive it at 522.6 square centimetres from their own Vas and Cms rather than assume it, and the port is sized off that figure. On it, a 28.4 Hz motor with a 0.46 Qts gives one of the flattest passbands in the line, 1.32 dB of ripple, with a 32.5 Hz F3 and 1.69 dB in the car at 32.5 Hz tuning.

Xmax is quoted at 70 percent BL and derated from 14 to 11.9 mm; the cone uses 6.0 of that at 400 watts with the 26 Hz filter set. The port takes 23.35 of the 25.05 inches a 29.5 inch cabinet gives at 18.6 metres per second against a 19.7 limit. I also build this driver as a 1.25 cubic foot sealed Down Fire; the graphs tab compares the two.

Questions

Why is this enclosure tuned to 32.5 Hz?

32.5 Hz puts the anechoic F3 at 32.5 Hz on 1.32 dB of ripple, one of the flattest passbands in the line, with 1.69 dB of in-car spread across 25 to 60 Hz; the Down Fire version reads 2.01 in the car. The port takes 23.35 of the 25.05 inches a 29.5 inch cabinet gives and runs at 18.6 metres per second in the channel against a 19.7 limit, 11.4 at the mouth. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz. In this cabinet that lands at 1.7 dB of in-car spread across 25 to 60 Hz.

Why the 20 degree wedge, and why rear-firing?

The raked face is the seat side. A factory rear seat back leans about 20 degrees off vertical, so the cabinet sits flat against it and uses floor a square box wastes. The baffle stays vertical and fires rearward into the trunk, which acts as the acoustic extension into the cabin. This one is 14.39 inches deep at the base and 8.75 at the top, 29.50 wide and 16 tall.

Do I need a subsonic filter?

Yes, at 26 Hz, 24 dB per octave. Below tuning a vented box stops loading the cone and excursion runs away toward DC. With the filter in place this cabinet puts the Prodigy NB2-12 at 50 percent of its usable travel at full rated power; without it there is no meaningful number to quote.

How much power can I run, and at what impedance?

Prodigy rate the NB2-12 at 400 W RMS and that is the thermal ceiling. The Performance Graphs tab shows the mechanical limit, the power at which the cone reaches the end of its travel in this cabinet: here the cone sits at 50 percent of usable travel at the rating, so heat is what stops you, not travel. A D2 coil is 4 ohms in series or 1 ohm in parallel; run series unless the amplifier is rated for 1 ohm. A D4 is 8 series or 2 parallel.

Would a sealed box be better for me?

Below about 22 Hz, yes. The sealed Down Fire we build for it is louder down there by up to 1.2 dB, because a sealed box rolls off gently where a vented one falls away steeply under tuning. Above that this alignment is the louder of the two for the same power. The Performance Graphs tab plots this cabinet against the 1.25 cu ft sealed Down Fire we build for this driver (PO 12-S DF NB2).

How does the side port work?

It is a triangular slot in the bottom-rear corner: the floor and the raked back wall are two sides, one bevelled panel is the third. It runs across the cabinet, opens into the box through a 4.40 inch gap at the far end and exits through the side panel as the same triangle. Straight, no bend: 23.35 inches of path and 16.9 square inches of channel running at 18.6 metres per second, 52 percent of its turbulence limit. The three mouth edges are rounded over at 1/2 inch, so the opening at the face is 27.7 square inches and the air leaves it at 11.4 metres per second against the 17.0 threshold where a slot port starts to chuff; the panel's throat end is rounded at 3/8 inch for the same reason. The terminal cup is on the other side.

Does this enclosure ship with polyfill?

No, and do not add any. Every sealed Proline X enclosure ships with polyfill; a ported one must not, because damping changes the effective volume the port is tuned against. The port here is cut to 23.35 inches for 32.5 Hz. Stuff it and you move the tuning without shortening the port.

Is the NB2-12 included?

No. This is an enclosure only, cut for the Prodigy NB2-12 specifically: the 11.200 inch cutout, the 6.750 inch mounting depth allowance and the 1.43 cubic foot alignment all come from Prodigy's published parameters. It fits both coil versions; the alignment published here is the D4. Bring your own driver.

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