Proline X
Performance Optimized Down Fire Wide Sealed 10" Enclosure | NVX VCW10v3
SKU: PO 10-S DFW VCW
- Alignment: 1.201 cu ft net. Qtc 0.734, Fc 35.8 Hz, F3 34.5 Hz (D2); Qtc 0.680, Fc 40.8 Hz, F3 42.5 Hz (D4)
- Down Fire Wide: 41"W x 12"D x 8.0625"H, 3" shallower than the standard 30 x 15 cabinet, for under rear seats
- Driver: NVX VCW10v3 (VCW102v3 D2 or VCW104v3 D4), 1000 W RMS, 22 mm Xmax, 6.30 in mounting depth
- Standoffs: Included, 1.75 in, shipped uninstalled. Installed height 9.8125 in
Financing available. Choose Shop Pay Installments at checkout.
Performance Optimized Down Fire Wide Sealed 10" Enclosure | NVX VCW10v3
More enclosures cut for NVX subwoofers: NVX Subwoofer Boxes
Proline X Performance Optimized Down Fire Wide 10" Sealed
Under rear seat fitment for trucks and SUVs. Cut for the NVX VCW10v3
The Down Fire Wide Format
Down Fire Wide is the Performance Optimized answer to a specific problem: the space under the rear seat of a truck or SUV, or a narrow cargo floor, is long and shallow, and a 30 by 15 inch Down Fire cabinet will not go in it.
So the cabinet is turned sideways. This one runs 41 inches wide by 12 inches deep by 8.0625 inches tall. It is the same VCW10v3, in a cabinet 3 inches shallower front to back than our standard 30 by 15 inch VCW10v3 cabinet and 11 inches longer. The airspace given up in depth is recovered along the length, so the driver still gets a properly sized chamber rather than a compromised one.
Which one to choose. If you have 15 inches of depth, the standard 30 by 15 inch cabinet is the pick: it is shorter end to end and stands 8.58 inches tall. If depth stops at 12 inches and you have 41 inches of run, this is the cabinet that fits. Measure the depth first. Under seat spaces vary widely between cab configurations, and depth is almost always the limiting dimension.
Performance, Performance Optimized, and Micro
Proline X builds three tiers of Down Fire enclosure. The difference is not finish or materials, it is whether the cabinet was designed for a category or for a driver, and how much of the fitting work is already done for you.
| Performance | Performance Optimized | Micro Series | |
|---|---|---|---|
| Fitment | Universal. Accepts any subwoofer that clears the published cutout and mounting depth. | Woofer specific. Cut for one named subwoofer, with cutout, mounting depth, magnet clearance and displacement drawn in CAD from that driver. | Woofer specific. Cut for one named subwoofer. |
| Footprint | Sized to the driver diameter. 24.5 by 13.5 inches on the 10 inch. | Shared 30 by 15 inch platform on most builds. Down Fire Wide variants like this one run long and shallow for under seat fitment. | Compact per driver footprint. 21.5 by 14.5 inches on the 10 inch. |
| Front baffle | Single, 3/4 inch. | Double layer, outer layer machined as a flush recess. 1.5 inch. | Double, 1.5 inch. |
| Driver mounting | Solid flange. You drill your own mounting holes. | 8/32 threaded inserts, stainless machine screws included. | 8/32 threaded inserts, stainless machine screws included. |
| Joinery | V-groove and dado, CNC cut. | V-groove and dado, CNC cut, perimeter cross brace. | Stack fab, dowel reinforced. |
| Published alignment | Modeled Qtc profiles across a range of drivers. No single response curve. | A real predicted Qtc and F3 for that exact driver, calculated from its own Thiele-Small parameters. | Target alignment described in the listing. |
| Carpet | Gray standard, black optional. | Plush black. | Plush black. |
| Warranty | 1 year limited. | 1 year limited. | 2 years. |
Feet ship with every tier, uninstalled on purpose. Mount them where your floor wants them for a down fire install, or leave them off and run the cabinet front firing or up firing. The orientation is yours to choose.
This page is a Performance Optimized enclosure. The cutout, the cabinet height and the airspace all come from the NVX VCW10v3's own published numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.
Built Around the NVX VCW10v3
Nothing about this cabinet is generic. The baffle is cut to 9.65 in, NVX's published cutout, under the 11.06 in frame, and the airspace lands on 1.201 cubic feet net.
The VCW10v3 is NVX's 10 inch, rated 1000 watts RMS, with 22 mm of one-way excursion. It is 6.30 inches deep, which matters on a down fire, where the motor rises into the cabinet. Every figure comes from NVX's owner's manual and product pages for the VCW102v3 and VCW104v3, including the 0.150 cubic foot driver displacement and the bolt circle, so nothing here is estimated.
NVX's D2 and D4 columns disagree on Vas by 19 percent and each coil's own page confirms its own column, so both are solved here.
Net Volume, Not Gross
We build this cabinet at 1.201 cubic feet net, out of 1.360 gross after the brace and the 0.150 cubic foot driver displacement NVX publishes. One cabinet serves both coils: the VCW102v3 (D2) reads Qtc 0.734, Fc 35.8 Hz, F3 34.5 Hz, and the VCW104v3 (D4) reads Qtc 0.680, Fc 40.8 Hz, F3 42.5 Hz.
Height is the free dimension. With the footprint fixed at 41 by 12, the cabinet height was solved to put the chamber on the 1.20 cubic feet the standard cabinet holds, then rounded up to the next sixteenth so the airspace lands on the target rather than under it. The motor clears the top panel by 1.01 inches against our 0.75 inch minimum, so airspace set the height here, not clearance.
True net, not marketing net. Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not guessed from external dimensions minus wall thickness.
Down Fire Wide Construction
Cut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3/4 inch MDF, a dense 48.5 lb/ft³ board with a 200 psi internal bond and 410,000 psi MOE. Every panel joint is a machined interlocking groove that mechanically locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Corners are square on Down Fire cabinets.
The cabinet measures 41 inches wide by 12 inches deep by 8.0625 inches tall, measured in the down fire position and excluding standoffs. The 1.75 inch standoffs ship uninstalled so you can place them to suit your floor; installed, the finished stack is 9.8125 inches. Plan the space around that figure, not the cabinet height.
1.5 Inch Double Baffle
Two 3/4 inch layers laminated to 1.5 inches, with the outer layer machined as a flush recess so the driver bolts to the inner layer. 8/32 threaded inserts are pressed at the shop on the maker's published bolt circle, with stainless machine screws included. The VCW10v3's 11.06 inch frame sits on the 12 inch deep baffle.
Windowed U-Brace
A windowed U-brace dadoed to the shell ties the front and rear walls together across the 41 inch span, and polyfill is installed as a light wall lining.
Side-Mounted Terminal Cup
Proline X ABS and carbon fiber composite cup with stainless hardware and copper ring terminals, pre-wired in 12 gauge OFC. Side mounted so it stays accessible with the baffle facing the floor.
Standoffs Included
1.75 inch standoffs ship with the enclosure, uninstalled. Mount them for a down fire install, or leave them off and run the cabinet front firing or up firing.
Motor Clearance and Orientation
The motor rises off the baffle into the cavity, so on a down fire cabinet the clearance that matters runs to the top panel. The 6.30 inch mounting depth puts the motor 4.80 inches into a 5.8125 inch cavity, leaving 1.01 inches above the motor against a 0.75 inch minimum. Height was set by the airspace, above the minimum the clearance alone would have required.
At the 1.75 inch standoff the floor slot is 0.93 times the cone area, under the 1.0 we aim for. The 22 mm of excursion on this cone moves a lot of air, so if the floor allows, taller feet or a front-firing install give it more room. NVX does not publish a position on down firing this driver, and this cabinet makes no claim on their behalf.
Power and Wiring
NVX rates the VCW10v3 at 1000 watts RMS. The VCW102v3 (D2) wires to 4 ohms with its coils in series or 1 ohm in parallel. The VCW104v3 (D4) wires to 8 ohms in series or 2 ohms in parallel. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for; series wiring is the safe default.
NVX publishes the 10.24 in bolt circle for the VCW10v3, so the threaded inserts are pressed at the shop and the stainless machine screws are in the box. Bring your own VCW10v3; the driver is purchased separately. The enclosure carries a 1 year limited warranty.
Cut for the Driver, Not the Catalog
Down Fire Wide, built for the space under a rear bench, one at a time in Tullahoma, Tennessee. Questions on fitment or amplifier matching, call 931-563-5151.
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Down Fire Wide |
| Compatible Driver | NVX VCW10v3 (VCW102v3 D2 or VCW104v3 D4), quantity 1. Direct fit |
| Configuration | Single 10 inch, sealed down fire wide |
| Mounting Position | Under a rear seat or on a narrow cargo floor where depth is limited, baffle facing down on standoffs |
| Firing Direction | Downward. Feet ship uninstalled, so front or up firing is also possible |
| External Width | 41 in |
| External Depth | 12 in |
| External Height | 8.0625 in in the down fire position, excludes standoffs |
| Installed Height | 9.8125 in including the 1.75 in standoff |
| Internal Volume, Gross | 1.360 cu ft |
| Internal Volume, Net Acoustic | 1.201 cu ft after the brace and the 0.150 cu ft displacement NVX publishes |
| Height Set By | Airspace; clearance alone would allow a lower cabinet |
| Driver Mounting Depth | 6.30 in required, 1.01 in clearance above the motor |
| Floor Slot | 0.93 times the cone area at the 1.75 in standoff |
| Alignment, D2 | Qtc 0.734, Fc 35.8 Hz, F3 34.5 Hz anechoic |
| Alignment, D4 | Qtc 0.680, Fc 40.8 Hz, F3 42.5 Hz anechoic |
| Comparison, Standard Down Fire | 30 x 15 x 8.58 in, 1.20 cu ft net. Same airspace, deeper footprint |
| Woofer Opening | 9.65 in, NVX's published cutout |
| Frame Outer Diameter | 11.06 in, NVX published |
| Bolt Circle | 10.24 in, NVX published; threaded inserts pre-installed |
| Driver Displacement | 0.150 cu ft, NVX published |
| VCW102v3 (D2) Fs / Qts / Qes / Qms / Vas | 27.30 Hz / 0.560 / 0.630 / 5.50 / 24.50 L |
| VCW104v3 (D4) Fs / Qts / Qes / Qms / Vas | 32.40 Hz / 0.540 / 0.710 / 2.40 / 19.90 L |
| Driver Sd | 370 cm2, published by NVX |
| Xmax | 22 mm one way, NVX spec |
| Driver Power Handling | 1000 W RMS, NVX spec |
| Wiring Options | The VCW102v3 (D2) wires to 4 ohms with its coils in series or 1 ohm in parallel. The VCW104v3 (D4) wires to 8 ohms in series or 2 ohms in parallel. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for; series wiring is the safe default. |
| Parameter Source | NVX VCW102v3 / VCW104v3 owner's manual and nvx.com product pages |
| Material | Langboard Elite MDF |
| Construction | CNC cut, V-groove and dado joinery, square corners |
| Panel Thickness | 0.75 in |
| Front Baffle | 1.5 in double baffle, outer layer machined as a flush recess |
| Internal Bracing | Windowed U-brace, dadoed to the shell |
| Driver Mounting | Threaded inserts pre-installed on the published bolt circle, stainless machine screws included |
| Terminal Cups | One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC |
| Standoffs | Included, 1.75 in, shipped uninstalled |
| Damping | Light polyfill wall lining, does not alter acoustic volume |
| Carpet | Plush black |
| Warranty | 1 Year Limited |
| Built In | Tullahoma, Tennessee |
01Is it a sealed driver?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
1.201 cu ft against a 24.5 L Vas.
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 22.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 27.30 / 32.40 | Hz | free-air resonance |
| Qts | 0.560 / 0.540 | dual 2 ohm / dual 4 ohm | |
| Vas | 24.50 / 19.90 | L | equivalent compliance |
| Sd | 369.8 | cm² | effective piston area |
| Xmax | 22 | mm | one-way linear travel |
| Pe | 1000 | W | continuous RMS |
| SPL | 80.8 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by NVX VCW10v3 owner’s manual. Curves computed against this enclosure’s actual net airspace.
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.
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 |
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.
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.
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.
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
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
Hand-assembled at our facility in Tullahoma, TN. Every enclosure is inspected before it ships.
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.
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