Proline X
Performance Optimized Down Fire Wide Sealed 10" Shallow Sub Enclosure | Arc Audio SW10
SKU: PO 10-S DFW SW10
- Alignment: 0.557 cu ft net, 0.599 gross, on Arc's 0.6 gross optimum. Qtc 0.842, Fc 53.1 Hz, F3 45.9 Hz series; Qtc 0.861, Fc 53.0 Hz, F3 45.1 Hz parallel
- Down Fire Wide: 41"W x 12"D x 4.8125"H, 3" shallower than the standard 30 x 15 SW10 cabinet, for under rear seats. Installed height 6.5625" on the 1.75" standoffs
- Driver: Arc Audio SW10 (DVC 2Ω or 4Ω), 350W RMS / 700W peak, 2.4" mounting depth or 2.25" front loaded, 9.1" cutout
- Wiring: Series and parallel T/S data are nearly identical, so this cabinet is correct either way
- Build: V-groove and dado joinery, double layer 1.5" front baffle, windowed U-brace, side mounted 12 gauge OFC terminal cup, square corners
Financing available. Choose Shop Pay Installments at checkout.
Performance Optimized Down Fire Wide Sealed 10" Shallow Sub Enclosure | Arc Audio SW10
More enclosures cut for Arc Audio subwoofers: Arc Audio Subwoofer Boxes
Proline X Performance Optimized Down Fire Wide 10" Sealed
Under rear seat fitment for trucks and SUVs. Cut for the Arc Audio SW10
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 4.8125 inches tall. It is the same Arc Audio SW10, in a cabinet 3 inches shallower front to back than our standard 30 by 15 inch Arc Audio SW10 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 5.0625 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 Arc Audio SW10's own published numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.
Built Around the Arc Audio SW10
Nothing about this cabinet is generic. The baffle is bored to the SW10's 9.1 inch cutout, with a 10.3 inch outer diameter to clear, and the driver's 2.4 inch mounting depth, 2.25 inches front loaded, is the shallowest in the Proline X Down Fire program. Here it sits in a cabinet just 4.8125 inches tall on a 41 by 12 inch footprint.
The SW10 is a dual voice coil driver offered in dual 2 ohm or dual 4 ohm, rated 350 watts RMS and 700 watts peak. Cone area is 338.16 cm² and the force factor is 16.365 Tm wired in series.
Arc publishes full Thiele-Small data for this driver in both series and parallel wiring, which most manufacturers do not bother with, and the two land within a hair of each other: Fs 39.3 against 39.0 Hz, Qts 0.624 against 0.634, Vas 12.96 against 13.33 liters. One enclosure therefore serves both wiring choices properly. Wire for whatever load your amplifier is stable and efficient into.
Net Volume, Not Gross
We build this cabinet at 0.599 cubic feet gross, on Arc Audio's published optimum sealed recommendation of 0.6 gross. Net internal airspace after the brace and the driver's 0.037 cubic feet of displacement is 0.557 cubic feet. Arc publishes its sealed recommendations as gross rather than net, which is unusual, so both figures are listed in the specifications.
True net, not marketing net. Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.
Wired in series the system lands at Qtc 0.842, Fc 53.1 Hz, F3 45.9 Hz. Wired in parallel it lands at Qtc 0.861, Fc 53.0 Hz, F3 45.1 Hz. A Qts in the low 0.6 range is a healthy, moderate figure, so unlike a lot of shallow drivers this one reaches a properly controlled alignment rather than sitting underdamped regardless of box size.
Height is the free dimension. With the footprint fixed at 41 by 12, the cabinet height was solved to put the chamber on the 0.55 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 1.66 inches against our 0.75 inch minimum, so airspace set the height here, not clearance.
The tradeoff on this driver is worth stating plainly. A 39.3 Hz free air resonance and a 12.96 liter Vas are both the price of a 2.4 inch motor, and they put F3 in the mid 40s rather than the 30s. What you get in exchange is a cabinet under five inches tall that also fits a 12 inch deep space. Arc's own documentation notes that cabin gain adds roughly 12 dB per octave below 50 Hz in most vehicles, and firing down into the floor this driver is built to lean on that.
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 4.8125 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 6.5625 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. The driver lands on 8/32 threaded inserts, with stainless machine screws included. The SW10's 10.3 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.
Power and Wiring
Arc rates the SW10 at 350 watts RMS with 700 watts peak. It is dual voice coil in 2 ohm or 4 ohm, and final impedance is set at the driver: a dual 2 ohm presents 4 ohms in series or 1 ohm in parallel, a dual 4 ohm presents 8 ohms in series or 2 ohms in parallel. Since the series and parallel Thiele-Small figures are effectively identical, the enclosure alignment holds either way. Confirm the load against your amplifier's minimum stable impedance before powering the system.
One side-mounted terminal cup, pre-wired in 12 gauge OFC. Bring your own Arc Audio SW10; 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.
| Series | Proline X Performance Optimized Down Fire Wide |
| Compatible Driver | Arc Audio SW10 (Dual 2Ω or Dual 4Ω) |
| Enclosure Type | Sealed | Down Fire Geometry | Floor-Coupled |
| Intended Fitment | Under The Rear Seat Of Trucks And SUVs, Or Narrow Cargo Floors, Where Depth Is The Limiting Dimension |
| Firing Direction | Down Firing, Driver Fires Toward Floor |
| External Width | 41 Inches |
| External Depth | 12 Inches |
| External Height | 4.8125 Inches |
| Dimension Reference | All External Dimensions Measured In Down Fire Position, Excluding Standoffs |
| Installed Height | 6.5625 Inches With The 1.75 Inch Standoffs |
| Internal Volume (Gross) | 0.599 Cubic Feet, On Arc's Optimum Sealed Spec of 0.6 Gross |
| Internal Volume (Net) | 0.557 Cubic Feet After 0.037 Cubic Feet Driver Displacement |
| Arc Published Sealed Range | 0.4 Min / 0.6 Optimum / 0.9 Max (All Gross) |
| Target System Qtc | 0.842 Series / 0.861 Parallel |
| Predicted Fc | 53.1 Hz Series / 53.0 Hz Parallel |
| Predicted F3 | 45.9 Hz Series / 45.1 Hz Parallel |
| Comparison, Standard 30x15 SW10 | 30 x 15 x 5.0625 Inches, 0.55 Cubic Feet Net. Same Driver, Deeper Footprint |
| Driver Fs | 39.3 Hz Series / 39.0 Hz Parallel |
| Driver Qts | 0.624 Series / 0.634 Parallel |
| Driver Qes / Qms | 0.723 / 4.563 Series | 0.736 / 4.589 Parallel |
| Driver Vas | 12.96 Liters Series / 13.33 Liters Parallel |
| Driver Bl | 16.365 Tm Series / 8.085 Tm Parallel |
| Driver Mms | 204.58 g Series / 201.79 g Parallel |
| Driver Re | 3.83 Ohms Series / 0.97 Ohms Parallel |
| Driver Sd | 338.16 cm² |
| Driver Sensitivity | 83.4 dB (1W/1m) |
| Driver Power Handling | 350 Watts RMS / 700 Watts Peak |
| Mounting Depth Required | 2.4 Inches / 2.25 Inches Front-Load (Arc Spec) |
| Woofer Opening | 9.1 Inches Cutout / 10.3 Inches Outer Diameter (Arc Spec) |
| Standoffs | 1.75 Inch, Included, Shipped Uninstalled |
| Material | Langboard Elite 3/4" MDF |
| Joinery | V-Groove and Dado (CNC-Cut) |
| Construction | ShopSabre CNC / Windowed U-Brace |
| Panel Thickness | 3/4 Inch |
| Front Baffle Construction | Double-Layer 1.5" MDF (Two 3/4" Sheets Bonded) |
| Corner Profile | Square (Down Fire Series Standard) |
| Driver Mounting | 8/32 Threaded Inserts | Stainless Steel Machine Screws Included |
| Voice Coil Configuration | Dual Voice Coil, Final Impedance Set At The Driver |
| Terminal Cup | Proline X ABS/Carbon Fiber Composite | Side Mounted | 12g OFC Pre-Wired |
| Internal Wiring | 12 Gauge OFC, Pre-Wired To The Terminal Cup |
| Damping | Polyfill Pre-Installed As A Light Wall Lining |
| Carpet Finish | Plush Black |
| Bundle Options | Enclosure Only (Bring Your Own Arc Audio SW10) |
| Warranty | 1-Year Limited (Enclosure) |
| Built In | Tullahoma, Tennessee, USA |
01Is it a sealed driver?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
0.557 cu ft against a 13.0 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 14.7 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 39.30 | Hz | free-air resonance |
| Qts | 0.624 / 0.634 | series / parallel | |
| Vas | 12.96 / 13.33 | L | equivalent compliance |
| Sd | 338.2 | cm² | effective piston area |
| Xmax | 14.7 | mm | one-way linear travel |
| Pe | 350 | W | continuous RMS |
| SPL | 82.2 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by arcaudio.com SW10 published specification table. 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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