PO 10-P DF NB2 placeholder
PO 10-P DF NB2 placeholder

Proline X

Performance Optimized Down Fire Ported 10" Enclosure | Prodigy NB2-10

SKU: PO 10-P DF NB2

QUICK SPECS
  • Alignment: 1.18 cu ft net vented at 35.0 Hz. F3 30.3 Hz anechoic, 2.18 dB passband ripple
  • Driver: Prodigy NB2-10 D4, 350 W RMS, 14.0 mm Xmax at 70% BL, 34.30 Hz Fs
  • Build: Proline X V-groove and dado joinery, L-wrap slot port with a faceted 90 degree bend, double-layer 1.5" baffle, side-mounted terminal cup
  • Cabinet: 31" W x 14.50" D x 7.75" H measured in down fire position, square corners, ships dry
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Shipping Included No freight charges at checkout. What you see is what you pay.
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Built in Tennessee CNC cut from 3/4" Langboard Elite MDF. V-groove and dado joinery.
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Advanced Terminal Cup Built in-house. ABS/Carbon Fiber. Stainless steel hardware. Copper ring terminals.
$ 299.99
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PO 10-P DF NB2 placeholder

Performance Optimized Down Fire Ported 10" Enclosure | Prodigy NB2-10

Regular price $ 299.99
Sale price $ 299.99 Regular price
Unit price
Enclosure Type Ported
External Dimensions 31" W x 14.50" D x 7.75" H (measured in down fire position)
Net Volume 1.18cu ft
Tuning Frequency 35.0 Hz
Port Area 18.8 Square Inches
Cutout Diameter Direct Fit
Front Panel Thickness 1.5"
INSTALLER'S TAKE

Every ported box involves an argument about space, and this is the one where the space won. 14.5 inches of external depth is 3.5 inches narrower than the biggest cabinet in this line, and that is the difference between a box that fits behind a seat or under a cargo floor and one that does not.

It works because of the driver, not in spite of it. 21.1 litres of Vas is small, and a small Vas motor is happy in a small box. Trying this footprint with the X2V2 and its 79.3 litres would produce a badly compromised alignment; here it produces 1.18 cubic feet and a 35 Hz tuning with no strain anywhere.

The number that surprises people is the F3. 30.3 Hz anechoic out of a ten, which is deeper than either IDQ twelve in this same range reaches. Cone area is not what sets low-frequency extension. The alignment is.

Be honest about the trade though. 4.3 dB of in-car spread across 25 to 60 Hz is the least flat result of the four Prodigy cabinets. You are buying reach and size, not neutrality. If you want flat and you have the room, the NB2-12 is 1.6 dB.

Dual 4 ohm, 2 ohms parallel or 8 ohms series. 350 W RMS rated. Subsonic at 28 Hz and leave it dry.

Product Details
Specifications
Performance Graphs
Materials
Product Details

Proline X Performance Optimized Down Fire 10" Ported

The smallest cabinet in the ported line, at 14.5 inches deep

1.18 cu ft net Tuned 35.0 Hz F3 30.3 Hz L-wrap slot port Cut for the Prodigy NB2-10 Built in Tennessee
1.18cu ft net
35.0Hz tuning
30.3Hz F3 anechoic
18.8sq in port area

Why this driver is vented at 35.0 Hz

This is the compact one. At 31 by 14.5 by 7.75 inches it is the smallest cabinet in the ported Down Fire line by a clear margin, and it holds 1.18 cubic feet net against a driver with only 21.1 litres of Vas. A small Vas means a driver that does not need much air to work, which is what makes a ported ten fit under a cargo floor at all.

Tuned to 35.0 Hz the NB2-10 reaches an anechoic F3 of 30.3 Hz, which is deeper than either of the twelve-inch IDQ builds manage. A ten inch cone in a properly vented box outreaching a twelve in a bigger one is not a trick; it is what happens when the alignment matches the motor instead of the badge.

The port is the product

A ported cabinet is easy to get wrong and the failure is audible. This one uses an L-wrap slot port: a single folded wall running down the long side of the box past the woofer ring, turning once through a faceted 90 degree bend, and opening through a chamfered corner. One wall, one bend, 27.63 inches of centreline path.

The channel is 3.00 inches wide by 6.25 tall, 18.8 square inches, and it exits through a 22.1 square inch mouth. Air leaves at 14.1 metres per second at the tuning frequency, against the 17.0 metre per second threshold where a slot port starts to chuff. The bend is faceted rather than square because the inner corner of a 90 degree turn is where flow separates, and a sharp corner there is what you hear.

This enclosure ships dry. Polyfill goes in every sealed Proline X cabinet we build. It does not go in this one. Damping material in a vented box changes the effective volume the port is tuned against, which moves the tuning frequency away from the 35.0 Hz the port length was cut for. Adding it does not make a ported box sound like a bigger ported box; it makes it a mistuned one.

Run a subsonic filter

This is not optional advice on a vented enclosure. Below tuning the port stops loading the cone and excursion climbs without limit toward DC, so a 28 Hz high-pass at 24 dB per octave is part of the specification rather than a refinement of it. Set it and the same cabinet takes substantially more power for the same cone travel. Leave it out and the driver runs out of suspension on material you cannot hear.

Every wattage on the Performance Graphs tab is a mechanical limit, not an electrical one: it is the power at which the cone reaches the end of its linear travel in this box. What the voice coil can dissipate as heat is a separate ceiling set by Prodigy, not by the cabinet.

Cut for this driver, not for a catalogue

Mounting

Cut to Prodigy's published 9.125 inch cutout with a 11.250 inch ring bonded under the baffle. The ring drops into a machined recess so it self-centres, and it roughly doubles the glue area over a butt joint.

Threaded, not screwed

Eight #8-32 hurricane nuts are driven into the ring before it is bonded, so the driver mounts into steel rather than into MDF and survives being unbolted more than once. The ring is cut with sixteen positions so the driver can be clocked to whatever orientation the install needs; eight are fitted.

Braced

A windowed brace sits between the woofer cutout and the port terminus, 3.41 inches clear of the cutout edge. The window is not weight saving: a solid panel there would split the cavity and turn the cabinet into a bandpass.

Joinery

V-groove and dado throughout, 0.75 inch material, double-layer 1.5 inch baffle. The walls seat into dados in both the lid and the baffle rather than butting against them.

Power, wiring and warranty

Prodigy rate the NB2-10 at 350 W RMS. Terminal cup is side mounted, as on every Performance Optimized cabinet. If you are running a dual 2 ohm driver, note that parallel wiring presents 1 ohm, which many amplifiers are not stable into; series at 4 ohm is the safe default unless yours is rated for it.

Performance Optimized carries a 1-year warranty. The enclosure is built to order in Tullahoma, Tennessee, and the driver is not included.

Cut, folded and finished for the Prodigy NB2-10. Nothing on this page is a rule of thumb: the alignment, the port geometry and the power figures all come from Prodigy's published parameters run through our own solver.

Specifications
SeriesProline X Performance Optimized Down Fire
Driver-Specific FitmentProdigy NB2-10 D4
Enclosure TypePorted | Down Fire Geometry | Floor-Coupled
Baffle ConfigurationDown Firing - Driver Fires Toward Floor
External Width31 Inches
External Depth14.50 Inches
External Height7.75 Inches
Dimension ReferenceAll External Dimensions Measured In Down Fire Position
Internal Volume (Gross)1.39 Cubic Feet
Internal Volume (Net After Displacement)1.18 Cubic Feet
Port TypeL-Wrap Slot | One Folded Wall | Single Faceted 90 Degree Bend
Port Tuning (Fb)35.0 Hz
Port Channel3.00 x 6.25 Inches (18.8 Square Inches)
Port Path Length27.63 Inches (Centreline)
Port Mouth Area22.1 Square Inches (2.50 Inch Corner Chamfer)
Port Air Velocity14.1 m/s At Tuning (17.0 m/s Chuff Threshold)
Predicted F330.3 Hz (Anechoic)
Passband Ripple2.18 dB (Anechoic)
Subsonic Filter28 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs34.30 Hz
Driver Qts0.514
Driver Qes0.611
Driver Vas21.054 Liters / 0.744 Cubic Feet
Driver Sd326.6 Square Centimeters
Driver Mms165.22 g
Driver BL20.11
Driver Re6.1 Ohm
Driver Xmax14mm (One-Way at 70% BL)
Excursion Design BasisDerated To 11.9mm For Alignment - Prodigy Publishes At 70% BL
Driver Displacement0.11 Cubic Feet (Published by Prodigy)
Driver Power Handling350 Watts RMS
Driver Overall Diameter10.250 Inches (Prodigy Spec)
Mounting Depth Required5.625 Inches (Prodigy Spec)
Cutout Diameter9.125 Inches (Prodigy Spec)
Woofer Ring11.250 Inch OD, Bonded Under The Baffle In A Machined Recess
MaterialLangboard Elite 3/4" MDF
ConstructionShopSabre CNC / Windowed Brace Between Cutout And Port Terminus
JoineryV-Groove and Dado (CNC-Cut)
Front Baffle ConstructionDouble-Layer 1.5" MDF | Outer Layer Flush Recess, Driver Mounts To Inner Layer
Corner ProfileSquare (Down Fire Series Standard)
Mounting Hardware8 x #8-32 Hurricane Nuts Fitted (16 Positions Cut For Driver Orientation) | Stainless Steel Machine Screws Included
Terminal CupProline X ABS/Carbon Fiber Composite | Side Mounted | 12g OFC Pre-Wired
DampingNone - Ships Dry. Polyfill Detunes A Ported Enclosure
Recommended Power244-350 Watts RMS (Prodigy Rated: 350W RMS)
Carpet FinishPlush Black
Bundle OptionsEnclosure Only (Bring Your Own Prodigy NB2-10)
Warranty1-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA
Performance Graphs
Net airspace
1.18
cu ft
Tuning
35.0
Hz · Fb
Half power
30.3
Hz · F3, anechoic
Xmax at
1415
W RMS · 28 Hz subsonic
Tighter filter
1743
W RMS · 33 Hz subsonic
Port
14.1
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 = 56.1
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 EBP 56.1
NB2-10 D4 · EBP 56.1
Between 50 and 100 a driver takes either load, and the choice becomes one of priorities rather than of physics. The NB2-10 D4 reads 56.1. 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

1.18 cu ft net against a 21.1 L Vas, vented at 35.0 Hz.

Fb = 35.0 Hz  ·  F3 = 30.3 Hz  ·  passband ripple 2.18 dB
20 30 50 70 100 150 200 +6 +0 −6 −12 −18 −24 FREQUENCY · Hz LEVEL · dB −3 dB Fb 35.0
NB2-10 D4 · Fb 35.0 Hz, F3 30.3 Hz
Anechoic, before any cabin gain, with the 28 Hz subsonic filter already applied. The vent takes over below 35 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

The same cabinet, the same 1.18 cu ft, changing only the alignment.

Ported Fb 35.0 Hz  ·  the same box sealed would run Qtc 0.66, Fc 44 Hz
20 30 50 70 100 150 200 +6 +0 −6 −12 −18 −24 FREQUENCY · Hz LEVEL · dB +6.4 dB at 37 Hz
Ported · 1.18 cu ft, Fb 35.0 HzSealed · the same 1.18 cu ft, Qtc 0.66
Shaded blue is where the ported alignment is louder for the same power, orange where the sealed one is. Across 25 to 60 Hz the vent is worth 6.4 dB at its widest and 4.5 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 curves with cabin gain applied, 45 Hz corner, 18 dB ceiling.

Flatness across 25–60 Hz: ported 4.3 dB spread, the same box sealed 3.0 dB
20 30 50 70 100 150 200 +6 +0 −6 −12 −18 −24 FREQUENCY · Hz LEVEL · dB +6.4 dB at 37 Hz
Ported, in-car · 4.3 dB spreadSealed, in-car · 3.0 dB spread
Cabin gain lifts both alignments 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 4.3 dB of spread against 3.0 dB for the same cabinet sealed. The sealed curve is flatter on paper; the ported one trades that for output. Note where the curves cross. Below about 24 Hz the sealed alignment becomes the louder of the two and stays louder all the way down, by up to 4.1 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 24 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 NB2-10's published 14.0 mm. Both traces are filtered, because a ported box has no honest unfiltered number.

PXmax = 1415 W at a 28 Hz subsonic  →  1743 W at 33 Hz
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 1415 W reaches Xmax here
1415 W · subsonic at 28 Hz, 24 dB/oct1743 W · subsonic at 33 HzXmax 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. At a 28 Hz subsonic that is 1415 W, reached first at 27 Hz; tightening the filter to 33 Hz buys 1743 W. There is no unfiltered figure on this page because a vent unloads the cone below tuning and excursion runs away toward DC: on a sealed build the subsonic filter is an improvement, here it is required equipment. 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 — NB2-10 rate this one at 350 W RMS, and that is the number that binds first here: heat stops you before travel does, so treat 350 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: NB2-10 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.
Materials
Material

Built From a Spec Sheet, Not a Sales Sheet

Every Proline X Performance Series enclosure is CNC-cut from Langboard Elite MDF, 3/4" (18mm) panels produced to published mill specifications. Most enclosure manufacturers source generic MDF without published data. We can tell you the internal bond rating, the modulus of elasticity, the modulus of rupture, and the face and edge screw holding strength for every panel in this enclosure, because we chose the material based on those numbers, not on price or availability.

Langboard Elite is produced in the United States. The specifications below are pulled directly from Langboard's published mill data and are verifiable. This is the same panel stock used in our full Proline X lineup.

Specifications

Langboard Elite MDF: Published Mill Data

Property Value Why It Matters
Panel Stock Langboard Elite MDF Named, verifiable panel source, not generic "high-density MDF"
Thickness 3/4" (18mm) Industry standard for subwoofer enclosures; panels below this flex under pressure
Density 48.5 lbs/ft³ Higher density = less porosity, better screw retention, reduced resonance
Internal Bond 200 psi Measures resistance to delamination under sustained internal pressure. The most enclosure-relevant spec on this sheet
Modulus of Rupture (MOR) 4,200 psi Bending strength before the panel breaks, relevant for larger unsupported baffle spans
Modulus of Elasticity (MOE) 410,000 psi Stiffness under load; higher MOE means less panel flex under bass pressure, less resonance
Face Screw Holding 325 lbs How firmly the panel surface holds a screw; critical for baffle joint integrity over time
Edge Screw Holding 250 lbs Panel edge retention, relevant for every joint that isn't face-to-face
Internal Bond

200 psi: The Number That Actually Matters for Enclosures

The internal bond rating measures how well the MDF panel resists delamination under sustained pressure applied perpendicular to the face. In a subwoofer enclosure, every bass transient generates a pressure pulse that pushes outward on every panel simultaneously. A panel that begins to delaminate internally loses stiffness gradually. The symptoms are slow: a box that starts to sound softer, less defined, less punchy over months of use. 200 psi internal bond is the spec that determines how long this enclosure holds its acoustic integrity under daily use at real power levels.

Stiffness

410,000 psi MOE: Less Flex, Less Resonance

The modulus of elasticity measures panel stiffness, its resistance to bending under load. A stiffer panel flexes less under the pressure generated by a high-excursion driver at volume. Panel flex is a source of acoustic coloration: the panel itself begins to radiate sound at its own resonant frequency, adding distortion to the output. 410,000 psi stiffness combined with V-groove and dado joinery means the panels stay rigid and the bracing controls resonance at the structure level, not the panel level. The bass you hear comes from the driver, not the box.

Screw Holding

325 lb Face / 250 lb Edge: Joints That Stay Locked

Screw holding strength determines how firmly the panel grips a fastener at the face and at the edge. This matters most at the baffle joint, where the front panel meets the side panels and where the driver is mounted. A panel with low screw holding strength allows fasteners to loosen over time under vibration, leading to air gaps at the joint and loss of acoustic seal. 325 lb face screw holding strength means the baffle hardware stays put. Combined with dado joinery and adhesive, the front panel on a Proline X Performance Series enclosure is not going anywhere.

Sourcing

Named Panel Stock: Not "Premium MDF"

The phrase "premium MDF" or "high-density MDF" appears on marketing copy for enclosures across every price point, from $40 to $400. It is not a specification. It is a description with no defined standard. Langboard Elite is a named, sourced, mill-documented product with published data. We name it in our copy because naming it holds us accountable to the spec. You can look up Langboard Elite independently, verify the numbers on this page, and confirm you are getting what we say you are getting. That is the point.

Why Proline X?

Most enclosures are built to a price point. Proline X is built to a spec. Every box starts with published-data MDF, gets CNC-cut to exact internal volume, and is assembled by hand in our Tennessee facility. The difference shows up in the measurements, and in how the box holds up two years into daily use.

CNC-Cut to Spec

CNC-Cut to Spec

Panels are machine-cut on ShopSabre CNC routers and joined with V-groove and dado joinery. Consistent geometry, no hand-cut variance, no gaps at the joints.

Handcrafted in USA

Handcrafted in USA

Hand-assembled at our facility in Tullahoma, TN. Every enclosure is inspected before it ships.

Tuned to the Build

Tuned to the Build

Internal volume and port geometry are calculated to spec and CNC-cut to exact dimensions. The box performs the same way every time.

Frequently Asked Questions

Why is this enclosure tuned to 35.0 Hz?

Does this enclosure ship with polyfill?

Do I need a subsonic filter?

How much power can I run?

Would a sealed box be better for me?

What is the L-wrap port and why does it matter?

How is this enclosure built?

Is the NB2-10 included?

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