Proline X Performance Optimized down fire sealed 10 inch subwoofer enclosure for the Prodigy NB2-10
Proline X Performance Optimized down fire sealed 10 inch subwoofer enclosure for the Prodigy NB2-10

Proline X

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

SKU: PO 10-S DF NB2

QUICK SPECS
  • Alignment: 0.96 cu ft net, Qtc 0.640, Fc 42.7 Hz, F3 47.2 Hz - best-damped alignment in the Down Fire line
  • Driver: Prodigy NB2-10D4 (DVC 4Ω), 350W RMS / 700W peak, 14mm Xmax at 70% BL, 5.625" mounting depth
  • Build: Proline X V-groove and dado joinery, double-layer 1.5" front baffle with flush outer recess, milled magnet relief, 12g OFC side-mounted terminal cup
  • Cabinet: 30"W x 15"D x 7.25"H measured in down fire position, square corners
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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.
$ 229.99
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Proline X Performance Optimized down fire sealed 10 inch subwoofer enclosure for the Prodigy NB2-10

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

Regular price $ 229.99
Sale price $ 229.99 Regular price
Unit price
Enclosure Type Sealed
External Dimensions 30" W x 15" D x 7.25" H (measured in down fire position)
Net Volume 0.96cu ft
Tuning Frequency N/A (Sealed)
Cutout Diameter Direct Fit
Front Panel Thickness 1.5"
Max Mounting Depth Direct Fit
INSTALLER'S TAKE

Qtc 0.640. That is the best-damped alignment in this entire program, across every driver family we have built for, and it happened by accident.

Here is the sequence. The NB2-10D4 mounts 5.625 inches deep. Our double baffle recovers 0.75 of that because the outer layer is a flush recess and the driver bolts to the inner layer. The milled magnet relief recovers another 0.375. Add half an inch of clearance behind the motor and the minimum internal height is 5 inches, which is 0.96 net on this footprint. Prodigy recommends 0.65. We cannot build 0.65 with this driver in the box.

Normally I would flag forced oversizing as a compromise. Not here. At 0.65 net this driver sits around Qtc 0.72. At 0.96 it drops to 0.640, which is tighter, lower group delay, shallower rolloff slope, and about a hertz deeper. The constraint made the box better.

On the driver: 14mm of Xmax and a double-stacked magnet at this price point are not normal. Most drivers in this bracket run a single magnet and 10 to 12mm. The detail I appreciate most is the tinsel leads stitched to the spider. Unstitched leads slap against the cone at high excursion and develop a ticking noise that gets worse over months. Prodigy solved it.

One thing worth knowing before you commit: at 5.625 inches this is not a shallow driver, and the cabinet is 7.25 inches tall as a result. If you need under-seat clearance, the NB3 shallow series in this same Down Fire line comes in at 6.25 inches. If you have the room, the NB2 is the better performer of the two.

Dual 4 ohm coils, so 2 ohms parallel or 8 ohms series at the driver. Target 250 to 350 watts RMS.

Product Details
Specifications
Performance Graphs
Materials
Product Details

The Performance Optimized Down Fire Sealed 10" Enclosure for the Prodigy NB2-10D4 is a sealed cabinet built around Prodigy's daily-driver 10 inch subwoofer, and it happens to produce the best-damped alignment in the entire Proline X Down Fire line.

The Prodigy NB2-10D4 is a dual 4-ohm subwoofer rated 350 watts RMS and 700 watts peak, with 14mm of one-way Xmax at 70% BL. A 2.0 inch four-layer copper voice coil on a black aluminum former, double-stacked magnet motor, reinforced paper cone, cotton-blend spider with tinsel leads stitched to the spider, and a dual cooling system using a center pole vent plus radial backplate holes. Mounting depth is 5.625 inches.

The 0.96 cubic foot net volume produces Qtc 0.640, Fc 42.7 Hz, and a predicted F3 of 47.2 Hz. That Qtc is the lowest of any enclosure in this program, and it is genuinely excellent territory: below unity, tight and controlled, with the shallow rolloff slope and low group delay that a well-damped sealed alignment gives you.

Worth explaining how it got there, because it was not chosen. The NB2-10D4 mounts 5.625 inches deep, which is substantially deeper than the shallow drivers most Down Fire cabinets are built around. On our double baffle the outer 3/4 inch layer is machined as a flush recess and the driver bolts to the inner layer, and we mill a 3/8 inch relief into the opposite panel behind the magnet, but even after both of those the minimum internal height lands at 5 inches. That works out to 0.96 net.

Prodigy recommends 0.65 cubic feet sealed. This cabinet cannot physically be that small with this driver in it. The oversizing is a fitment consequence, and it lands in your favor: Qtc drops from about 0.72 at Prodigy's figure to 0.640 here, which is better damped with slightly deeper extension.

Firing down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz, and in-car response extends well below the anechoic figure.

Construction is the full Proline X Performance Optimized platform: ShopSabre CNC-cut Langboard Elite MDF with V-groove and dado joinery, perimeter cross-bracing, and a double-layer 1.5 inch front baffle with the outer layer machined as a flush recess. Corners are square on Down Fire cabinets. The driver fires down into the floor with the terminal cup side mounted. Terminal cup is our Proline X ABS/carbon fiber composite pre-wired with 12 gauge OFC.

Bring your own Prodigy NB2-10D4. Dual 4-ohm, so you set your final impedance at the driver: 2 ohms with the coils in parallel, 8 ohms in series.

Manufactured in Tullahoma, Tennessee. 1-year enclosure warranty.

Specifications
Enclosure TypeSealed | Down Fire Geometry | Floor-Coupled
Driver-Specific FitmentProdigy NB2-10D4 (DVC 4Ω)
Internal Volume (Gross)1.07 Cubic Feet
Internal Volume (Net After Displacement)0.96 Cubic Feet
Prodigy Recommended Sealed Volume0.65 Cubic Feet (See FAQ On Why This Cabinet Is Larger)
Target System Qtc0.640 (Well Damped | Lowest In The Down Fire Line)
Predicted Fc42.7 Hz
Predicted F347.2 Hz
Driver Fs34.295 Hz
Driver Qts0.514
Driver Qes / Qms0.611 / 3.24
Driver Vas21.054 Liters / 0.744 Cubic Feet
Driver Mms165.223 g
Driver Cms139.032 µm/N
Driver BL20.11 T/m
Driver Re6.1 Ohm
Driver Xmax14mm (One-Way at 70% BL)
Driver Displacement0.11 Cubic Feet (Published by Prodigy)
Driver Sensitivity84.2 dB (1W/1m)
Driver Power Handling350 Watts RMS / 700 Watts Peak
Driver Voice Coil2.0 in | 4-Layer Copper | Black Aluminum Former
Driver MotorDouble-Stacked Magnet | Center Pole Vent + Radial Backplate Holes
Mounting Depth Required5.625 Inches (Prodigy Spec)
Cutout Diameter9.250 Inches (Prodigy Spec)
Driver Overall Diameter10.375 Inches (Prodigy Spec)
Baffle ConfigurationDown Firing - Driver Fires Toward Floor
MaterialLangboard Elite 3/4" MDF
Front Baffle ConstructionDouble-Layer 1.5" MDF | Outer Layer Flush Recess, Driver Mounts To Inner Layer
Magnet Relief3/8" Deep Milled Relief In Opposite Panel For Motor Clearance
Motor Clearance0.5 Inch Minimum Behind Magnet Vent
JoineryV-Groove and Dado (CNC-Cut)
Corner ProfileSquare (Down Fire Series Standard)
ConstructionShopSabre CNC / Perimeter Cross-Brace
External Width30 Inches
External Depth15 Inches
External Height7.25 Inches
Dimension ReferenceAll External Dimensions Measured In Down Fire Position
Voice Coil ConfigurationDual 4-Ohm | 2Ω Parallel or 8Ω Series At The Driver
Mounting Hardware8/32 Threaded Inserts | Stainless Steel Machine Screws Included
Terminal CupProline X ABS/Carbon Fiber Composite | Side Mounted | 12g OFC Pre-Wired
DampingPolyfill Pre-Installed
Recommended Power250-350 Watts RMS (Prodigy Rated: 350W RMS)
Carpet FinishDark Gray Trunkliner (Standard) or Plush Black (+$10)
Bundle OptionsEnclosure Only (Bring Your Own Prodigy NB2-10D4)
Warranty1-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA
Performance Graphs
Net airspace
0.96
cu ft per chamber
System Qtc
0.68
sealed
Half power
47.2
Hz · F3
Xmax at
316
W RMS · no filter
With 25 Hz subsonic
442
W RMS · +40%
Amplifier
350
W RMS recommended
This enclosure holds 0.96 cu ft net per chamber. In it the Prodigy Audio NB2-10 runs a system Qtc of 0.68 with half power at 47.2 Hz, and the cone reaches its 14.0 mm travel limit at 316 W, below the driver’s 350 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 442 W — +126 W, or 40 percent more power for the same 14.0 mm of travel.

01Is it a sealed driver?

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 D4 56.1
D4 · EBP 56.1
At 56.1 the NB2-10 sits in the transition band, not the sealed band. That is not a mismatch: a transition motor works in either alignment, and sealed buys a smaller box and a gentler roll-off at the cost of some low-end output. Stage 02 shows what this airspace actually does with it.

02What the box does to it

0.96 cu ft against a 21.1 L Vas.

α = Vas ÷ Vb = 0.77  ·  Fc = Fs√(α+1) = 46 Hz  ·  Qtc = 0.68
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
D4 · Qtc 0.68, Fc 46 Hz, F3 47.2 Hz
The box lifts resonance from 34.3 Hz free-air to 46 Hz and half power lands at 47.2 Hz, anechoic, before any cabin gain.

03The 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 14.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 316 W unfiltered  →  442 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 4 8 12 16 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 14.0 mm 316 W reaches Xmax here
D4 · 316 W, no filterD4 · 442 W with subsonic at 25 Hz, 24 dB/octXmax 14.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 14.0 mm. Unfiltered that is 316 W, reached first at 20 Hz. It sits under the 350 W the driver can take thermally, so the enclosure sets the ceiling, not the voice coil. The dashed traces are the same driver behind a subsonic filter at 25 Hz, 24 dB/oct: stopping the cone wasting travel below the passband lets it take 442 W before hitting the same 14.0 mm. That is 40 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs34.30Hzfree-air resonance
Qts0.514D4
Vas21.05Lequivalent compliance
Sd328.4cm²effective piston area
Xmax14mmone-way linear travel
Pe350Wcontinuous RMS
SPL83.3dB1 W / 1 m, derived from T/S

Driver parameters as published by prodigyaudio.com product page; Sd derived from Vas and Cms. Curves computed against this enclosure’s actual net airspace.

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 larger than Prodigy's recommended 0.65 cubic feet?

What does a Qtc of 0.640 actually mean?

How does the NB2 compare to the NB3 shallow series?

How do I wire this enclosure and set my impedance?

Where is the terminal cup located on a down fire enclosure?

Why are the corners square instead of radiused?

How is this enclosure built?

Is the Prodigy NB2-10 subwoofer included with this enclosure?

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