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Proline X PO 10-S DFW NB2 sealed down-fire wide enclosure for the Prodigy NB2-10, 41 inches wide by 7.125 inches tall, feet add 1.75 inches of height.
Proline X PO 10-S DFW NB2 sealed down-fire wide enclosure, end panel with side-mounted terminal cup, 7.125 inches tall by 12 inches deep.

Performance Optimized · Datasheet

Performance Optimized Down Fire Wide Sealed 10" Enclosure Prodigy NB2-10 · Single 10" Sealed enclosure

Net volume
1.023 cu ft after displacement
Max mounting depth
5.625 in, Prodigy spec
Cutout
9.250 in, Prodigy spec
External dimensions
41 in W × 7.125 in H × 12 in D
Front baffle
1.5 in double baffle, outer layer machined as a flush recess
Buy at Audio IntensityFactory-direct, ships from Tullahoma
Prodigy NB2-10Buy at Audio Intensity
  • Alignment: 1.023 cu ft net, Qtc 0.675, Fc 45.1 Hz, F3 47.3 Hz, below the maximally flat reference
  • Height: Set by the 5.625" mounting depth, 0.75" above the motor; more air than the standard box, lower Qtc
  • Driver: Prodigy NB2-10D4 (DVC 4Ω), 350W RMS / 700W peak, 14mm Xmax at 70% BL
  • Cabinet: 41"W x 12"D x 7.125"H measured in down fire position, square corners

Spec of record

Technical specifications

SeriesProline X Performance Optimized Down Fire Wide
Compatible DriverProdigy NB2-10D4 (DVC 4Ω). Direct fit
Enclosure TypeSealed, down fire, floor coupled
Intended FitmentUnder the rear seat of trucks and SUVs, or narrow cargo floors, where depth is the limiting dimension
Chamber ConfigurationSingle chamber, windowed U-brace, one side-mounted terminal cup
External Width41 in
External Depth12 in
External Height7.125 in, measured in down fire position, excludes feet
Installed Height8.875 in with the 1.75 in feet fitted
Internal Volume, Gross1.140 cu ft
Internal Volume, Net Acoustic1.023 cu ft after displacement
AlignmentQtc 0.675, Fc 45.1 Hz, F3 47.3 Hz anechoic
Height Set ByDriver clearance: 0.75 in above the motor
Comparison, Standard Down Fire30 x 15 x 7.25 in, 0.96 cu ft net
Cutout Diameter9.250 in, Prodigy spec
Mounting Depth Required5.625 in, Prodigy spec
Driver Fs34.295 Hz
Driver Qts0.514
Driver Qes / Qms0.611 / 3.24
Driver Vas21.054 L
Driver Xmax14mm one way at 70% BL
Driver Sensitivity84.2 dB (1W/1m)
Power Handling350 W RMS / 700 W peak
Driver Voice Coil2.0 in, 4-layer copper, black aluminum former
Driver MotorDouble-stacked magnet, center pole vent plus radial backplate holes
Recommended Power250 to 350 W RMS
Voice Coil ConfigurationDual 4-ohm, 2Ω parallel or 8Ω series at the driver
Driver Displacement0.11 cu ft, published by Prodigy
MaterialLangboard Elite 3/4 in MDF
ConstructionShopSabre CNC cut, V-groove and dado joinery, windowed U-brace
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Corner ProfileSquare, Down Fire series standard
Driver Mounting8/32 threaded inserts, stainless machine screws included
Terminal CupOne Proline X ABS and carbon fiber composite, side mounted
Internal Wiring12 gauge OFC
DampingPolyfill installed, light wall lining
Feet1.75 in, included, shipped uninstalled
CarpetPlush black
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.023
cu ft per chamber
System Qtc
0.68
sealed
Half power
47.3
Hz · F3
Xmax at
303
W RMS · no filter
With 25 Hz subsonic
433
W RMS · +43%
Amplifier
350
W RMS recommended
This enclosure holds 1.023 cu ft net per chamber. In it the Prodigy Audio NB2-10 runs a system Qtc of 0.68 with half power at 47.3 Hz, and the cone reaches its 14.0 mm travel limit at 303 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 433 W — +130 W, or 43 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

1.023 cu ft against a 21.1 L Vas.

α = Vas ÷ Vb = 0.73  ·  Fc = Fs√(α+1) = 45 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 45 Hz, F3 47.3 Hz
The box lifts resonance from 34.3 Hz free-air to 45 Hz and half power lands at 47.3 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 = 303 W unfiltered  →  433 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 303 W reaches Xmax here
D4 · 303 W, no filterD4 · 433 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 303 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 433 W before hitting the same 14.0 mm. That is 43 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.

From the shop floor

Installer's take

The NB2-10D4 mounts 5.625 inches deep, and that sets this cabinet's height, not a volume target.

Keep 0.75 inch above the motor and the cabinet is 7.125 tall. On a 41 by 12 footprint that holds 1.023 cubic feet net, more than the 0.96 of our standard 30 x 15 box. More air, lower Qtc: the safe direction.

Result: Qtc 0.675, Fc 45.1 Hz, F3 47.3 Hz. Below the 0.707 reference, so clean and controlled with a gentle rolloff that meets cabin gain.

14mm of Xmax and a double-stacked magnet at this price are not normal, and the tinsel leads stitched to the spider will not tick at high excursion.

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

Before you order

Questions

Why is this cabinet 41 inches wide instead of 30?

Because it is only 12 inches deep. The standard Performance Optimized Down Fire platform is 30 wide by 15 deep, and this application needs a cabinet that fits a space three inches shallower than that.

The airspace has to come from somewhere, so the cabinet runs 41 inches long instead of 30 and stands 7.125 inches tall. If you have 15 inches of depth, the standard cabinet is the pick; if your space is long and shallow, under a rear bench or on a narrow cargo floor, this is the shape that fits.

How does this compare to the standard 30 x 15 Prodigy NB2-10 enclosure?

The standard cabinet is 30 x 15 x 7.25 inches and holds 0.96 cubic feet net. This cabinet is 41 x 12 x 7.125 and holds 1.023 cubic feet net, 0.063 cubic feet more, because its height is set by the NB2-10's mounting depth rather than by a volume target. More air means a lower, more damped Qtc, which is the safe direction. The choice is about shape: the standard box needs 15 inches of depth, this one needs 12 inches of depth and 41 inches of run.

What alignment does this cabinet give, and what is the low-frequency extension?

The 5.625 inch mounting depth sets the cabinet height, and the airspace follows from it. At 1.023 cubic feet net: Qtc 0.675 with Fc at 45.1 Hz and a predicted F3 of 47.3 Hz. That is below the 0.707 reference: more damped, with a gentler rolloff.

Those are anechoic figures. Firing into the floor, the sealed rolloff meets rising cabin gain, so in-car response runs deeper than the numbers above.

How do I wire this enclosure and set my impedance?

One side-mounted Proline X terminal cup pre-wired in 12 gauge OFC. The NB2-10D4 is dual 4-ohm, so you set the load at the driver: coils in parallel for 2 ohms, or in series for 8 ohms.

Prodigy rates the driver at 350 watts RMS. Confirm your amplifier is stable at your chosen load and set gains for 250 to 350 watts.

Why is this enclosure larger than Prodigy's recommended sealed box?

Because the driver's mounting depth sets the minimum cabinet height. With the 5.625 inch driver in the flush recess and 0.75 inch kept above the motor, the cabinet is 7.125 inches tall, which on this footprint is 1.023 cubic feet net. A 0.65 cubic foot box cannot physically contain this driver here, and the larger box lowers Qtc, which is the safe direction.

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

Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup, and on a down fire cabinet that keeps the connection accessible with the enclosure installed, since the baffle faces 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.

How is this enclosure built?

V-groove and dado joinery, CNC cut on ShopSabre routers from Langboard Elite MDF. Every panel joint is a machined interlocking groove that mechanically locks the panels before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Corners are square, the Down Fire series standard, with no radii.

The front baffle is a double layer at 1.5 inches, with the outer layer machined as a flush recess so the driver bolts to the inner layer. A windowed U-brace ties the long panels together across the 41 inch span. Polyfill is installed as a light wall lining. Assembled and inspected in Tullahoma, Tennessee.

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

No. This listing is for the enclosure only. Bring your own Prodigy NB2-10D4. The cutout and mounting depth are cut specifically for this driver.

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