Shop
Proline X PO 10-S DFW NSW sealed down-fire wide enclosure for the NVX NSW10v3, 41 inches wide by 6.875 inches tall, feet add 1.75 inches of height.
Proline X PO 10-S DFW NSW sealed down-fire wide enclosure, end panel with side-mounted terminal cup, 6.875 inches tall by 12 inches deep.

Performance Optimized · Datasheet

Performance Optimized Down Fire Wide Sealed 10" Enclosure NVX NSW10v3 · Single 10" Sealed enclosure

Net volume
1.024 cu ft after displacement
Max mounting depth
5.36 in
External dimensions
41 in W × 6.875 in in the down fire position 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
NVX NSW10v3Buy at Audio Intensity
  • Alignment: 1.024 cu ft net. D2 Qtc 0.645, Fc 48.9 Hz, F3 54.1 Hz; D4 Qtc 0.687, Fc 46.9 Hz, F3 48.4 Hz; height set by motor clearance
  • Down Fire Wide: 41"W x 12"D x 6.875"H in down fire position, 3" shallower and 11" longer than the standard 30 x 15, for under rear seats and narrow cargo floors
  • Driver: NVX NSW10v3 (NSW102v3 D2 or NSW104v3 D4), 500 W RMS, 12.5 mm Xmax, 5.36 in mounting depth, 8.97 in cutout
  • Build: Windowed U-brace, 1.5" double baffle, one side-mounted terminal cup, 12g OFC
  • Standoffs: 1.75", ship uninstalled. Installed height 8.625"

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Down Fire Wide
Compatible DriverNVX NSW10v3 (NSW102v3 D2 or NSW104v3 D4), quantity 1. Direct fit
Enclosure TypeSealed, single driver, down fire, floor coupled
Intended FitmentUnder the rear seat of trucks and SUVs and narrow cargo floors, where depth is the limiting dimension
Firing DirectionDown firing, driver fires toward the floor. Standoffs ship uninstalled, so front or up firing is also possible
Chamber ConfigurationSingle sealed chamber, windowed U-brace, one side-mounted terminal cup
External Width41 in
External Depth12 in
External Height6.875 in in the down fire position, excludes standoffs
Installed Height8.625 in with the 1.75 in standoffs
Standard 30 x 15 Equivalent30 x 15 x 6.86 in, 0.93 cu ft net. Same driver, deeper and shorter footprint
Internal Volume, Gross1.082 cu ft
Net Volume1.024 cu ft after displacement
Height Set ByDriver clearance: the 5.36 in motor, 0.75 in minimum above it
Clearance Above Motor0.77 in
Alignment, D2Qtc 0.645, Fc 48.9 Hz, F3 54.1 Hz anechoic
Alignment, D4Qtc 0.687, Fc 46.9 Hz, F3 48.4 Hz anechoic
Woofer Opening8.97 in, NVX's published cutout
Frame Outer Diameter10.40 in, NVX published
Bolt Circle9.68 in, NVX published; threaded inserts pre-installed
Driver Mounting Depth5.36 in
NSW102v3 (D2) Fs / Qts / Qes / Qms / Vas38.67 Hz / 0.510 / 0.548 / 7.32 / 17.37 L
NSW104v3 (D4) Fs / Qts / Qes / Qms / Vas36.91 Hz / 0.540 / 0.612 / 4.59 / 17.89 L
Driver Sd340 cm2, published by NVX
Xmax12.5 mm, NVX spec; the manual does not state one-way or peak to peak
Driver Power Handling500 W RMS, NVX spec
Wiring OptionsD2: 4 ohm series or 1 ohm parallel. D4: 8 ohm series or 2 ohm parallel. Series is the safe default
Parameter SourceNVX NSW102v3 / NSW104v3 owner's manual and nvx.com product pages
Driver Displacement0.050 cu ft, published by NVX
MaterialLangboard Elite MDF
ConstructionCNC cut on ShopSabre routers, V-groove and dado joinery
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Internal BracingWindowed U-brace, dadoed to the shell
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
StandoffsIncluded, 1.75 in, shipped uninstalled
DampingPolyfill pre-installed as a light wall lining
CarpetPlush Black
Bundle OptionsEnclosure only, bring your own NSW10v3
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.024
cu ft
System Qtc
0.64–0.69
sealed
Half power
48.4–54.1
Hz · F3
Xmax at
277
W RMS · no filter
With 25 Hz subsonic
386
W RMS · +40%
Amplifier
500
W RMS recommended
This enclosure holds 1.024 cu ft net . In it the NVX NSW10v3 runs a system Qtc of 0.64–0.69 with half power at 48.4–54.1 Hz, and the cone reaches its 12.5 mm travel limit at 277 W, below the driver’s 500 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 386 W — +110 W, or 40 percent more power for the same 12.5 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 60.3–70.6
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 dual 2 ohm 70.6 dual 4 ohm 60.3
dual 2 ohm · EBP 70.6dual 4 ohm · EBP 60.3
At 60.3–70.6 the NSW10v3 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

1.024 cu ft against a 17.4 L Vas.

α = Vas ÷ Vb = 0.60  ·  Fc = Fs√(α+1) = 47–49 Hz  ·  Qtc = 0.64–0.69
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
dual 2 ohm · Qtc 0.64, Fc 49 Hz, F3 54.1 Hzdual 4 ohm · Qtc 0.69, Fc 47 Hz, F3 48.4 Hz
The box lifts resonance from 36.9–38.7 Hz free-air to 47–49 Hz and half power lands at 48.4–54.1 Hz, anechoic, before any cabin gain. Figures are NVX’s published NSW10v3 parameters from its owner’s manual and product pages, displacement included (0.050 cubic feet). One cabinet serves both coils; both are plotted.

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

PXmax = 277–282 W unfiltered  →  386–389 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 12.5 mm 277 W reaches Xmax here
dual 2 ohm · 277 W, no filterdual 4 ohm · 282 W, no filterdual 2 ohm · 389 W with subsonic at 25 Hz, 24 dB/octdual 4 ohm · 386 W with subsonic at 25 Hz, 24 dB/octXmax 12.5 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 12.5 mm. Unfiltered that is 277 W, reached first at 20 Hz. It sits under the 500 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 386 W before hitting the same 12.5 mm. That is 40 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs38.67 / 36.91Hzfree-air resonance
Qts0.510 / 0.540dual 2 ohm / dual 4 ohm
Vas17.37 / 17.89Lequivalent compliance
Sd339.7cm²effective piston area
Xmax12.5mmone-way linear travel
Pe500Wcontinuous RMS
SPL84.5dB1 W / 1 m, derived from T/S

Driver parameters as published by NVX NSW10v3 owner’s manual. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Measure the installed height, not the cabinet height. The box is 6.875 tall on its own and the standoffs add 1.75, so plan around 8.625 inches of stack on a 41 by 12 footprint.

The 5.36 inch motor sets this cabinet's height, not the airspace. With 0.75 inch above the magnet the wide box holds 1.024 cubic feet net, more than the 0.93 the standard 30 by 15 was built to, so both coils land a little lower in Qtc: 0.645 on the D2, 0.687 on the D4. More air is the safe direction.

Cut is 8.97, NVX's own figure, and the inserts are already pressed on their 9.68 bolt circle. It is sealed, so leave the polyfill as it is and run it at 500 watts or under.

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 under a rear seat or on a narrow cargo floor there is often not 15 inches to give.

The airspace lost from the depth is recovered from the length, so the cabinet runs 41 inches instead of 30 and stands 6.875 inches tall, with the same driver specific chamber. If you do have 15 inches of depth, the standard 30 by 15 cabinet is the better pick.

How does this compare to the standard 30 x 15 NSW10v3 enclosure?

The standard cabinet is 30 by 15 by 6.86 inches and gives the driver 0.93 cubic feet net. This one is 41 by 12 by 6.875 inches and gives the driver 1.024 cubic feet net. Here the height is set by the 5.36 inch motor's clearance rather than the airspace, so the wide box carries more air, which lowers Qtc slightly.

The choice is about shape: the standard box if you have 15 inches of depth, this one when depth is the limit and you have 41 inches of run.

What is the expected low-frequency extension?

In 1.024 cubic feet net the NSW102v3 (D2) lands at Qtc 0.645 with Fc at 48.9 Hz and an anechoic F3 of 54.1 Hz, and the NSW104v3 (D4) at Qtc 0.687 with Fc at 46.9 Hz and F3 at 48.4 Hz. Both sit below 0.707, so the rolloff is gentle rather than peaked.

Those figures exclude cabin gain. In a car the cabin adds real output below 50 Hz, so in-vehicle response runs deeper than the numbers above.

What amplifier power should I run, and how should I wire it?

NVX rates the NSW10v3 at 500 watts RMS, so target 350 to 500 watts RMS at the final load. The NSW102v3 (D2) wires to 4 ohms in series or 1 ohm in parallel; the NSW104v3 (D4) wires to 8 ohms in series or 2 ohms in parallel. Series wiring is the safe default, and you should confirm your amplifier's minimum stable impedance first.

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 in its installed position, 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, so every panel joint locks mechanically before adhesive is applied. The front baffle is a 1.5 inch double layer with the outer layer machined as a flush recess, and the driver lands on 8/32 threaded inserts with stainless machine screws. A windowed U-brace ties the long 41 inch panels together. Corners are square, the Down Fire series standard, which keeps the most internal volume for the footprint. Assembled and inspected in Tullahoma, Tennessee.

Do I need to add polyfill or damping?

No. Polyfill is already installed as a light wall lining, and the quantity is chosen so it does not change the acoustic volume. Do not add more: packing a sealed box makes it behave as though it were larger, which walks the alignment away from the 1.024 cubic feet this cabinet was built to.

Is the driver included, and are the threaded inserts installed?

No. This listing is for the enclosure only. Bring your own NVX NSW10v3; the driver is purchased separately. The cutout and mounting depth are direct fit, and the 1.75 inch standoffs ship uninstalled for an installed height of 8.625 inches.

Same series, same size

Other Performance Optimized models