Proline X
Performance Optimized Down Fire Sealed 10" Enclosure | Arc Audio A10
SKU: PO 10-S DF A10
- Alignment: 0.859 cu ft gross, roughly 0.80 net, matching Arc's published optimum sealed spec. Qtc 0.854 / F3 39.0 Hz (D4), Qtc 0.796 / F3 40.6 Hz (D2)
- Driver: Arc Audio A10D2 or A10D4, 250W RMS / 500W musical, 8mm Xmax, 26.995 Hz Fs, 3.77" mounting depth, 9.06" cutout
- Volume Convention: Arc publishes sealed recommendations as gross, not net; both figures are listed
- Build: V-groove and dado joinery, double layer 1.5" front baffle, perimeter cross-brace, side mounted 12 gauge OFC terminal cup
- Cabinet: 30"W x 15"D x 6.25"H measured in down fire position, square corners
Financing available. Choose Shop Pay Installments at checkout.
Performance Optimized Down Fire Sealed 10" Enclosure | Arc Audio A10
Proline X Performance Optimized Down Fire 10" Sealed
Cut and tuned for the Arc Audio A10
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, with cabinet height as the variable. A few drivers need a wider or deeper platform. | Compact per driver footprint. 21.5 by 14.5 inches on the 10 inch. |
| Front baffle | Single, 3/4 inch. | Double, 1.5 inch, outer layer machined as a flush recess. | 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 airspace, the cutout and the cabinet height all come from the Arc Audio A10's own published numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.
Built Around the Arc Audio A10
Nothing about this cabinet is generic. The baffle is bored to the A10's 9.06 inch cutout, the internal height is set by its 3.77 inch mounting depth and 4.24 inch overall depth, and the cavity is machined to the volume Arc Audio publishes for this driver. The finished cabinet stands 6.25 inches tall on a 30 by 15 inch footprint, measured in the down fire position, which fits under seats and in cargo wells that will not take a conventional box.
The number that sets this driver apart is its 26.995 Hz free-air resonance. That is exceptionally low for a 10 inch subwoofer of any depth, and unusual for one that mounts in under four inches. Most 10s sit in the mid to high 30s, and shallow 10s are typically worse because a shortened motor and a stiffer suspension push resonance up. Arc got this one down near 27 Hz on both coil variants.
Arc pairs that low Fs with a moderate Qts, 0.477 on the A10D2 and 0.506 on the A10D4. That is the combination that lets the driver reach a properly damped sealed alignment instead of being forced into an underdamped one. Xmax is 8mm one way, sensitivity is 85.4 dB at 1W/1m, and both variants are rated 250 watts RMS with 500 watts musical.
Net Volume, Not Gross
The machined cavity measures 0.859 cubic feet gross, which matches Arc Audio's own optimum sealed recommendation of 0.85 gross. After the driver's displacement is subtracted the working airspace is approximately 0.80 cubic feet net.
Read that pair of numbers carefully, because Arc publishes their sealed recommendations as gross volume rather than net, which is unusual. Almost every other manufacturer states net, meaning the airspace left after the driver's own displacement is removed. We built to Arc's gross figure as published, so this is the enclosure Arc designed the driver around. Both conventions are listed so you can compare against either one.
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.
The two coil variants land in different places in this volume. The A10D2 reaches Qtc 0.796 with F3 at 40.6 Hz, the more damped of the two, with tighter transient control. The A10D4 carries the higher Qts and lands at Qtc 0.854 with F3 at 39.0 Hz, a little less damped and a little lower. The D4 also runs considerably more motor force at 18.090 T against the D2's 13.766. Both are 250 watts RMS with identical fitment, so choose on the load your amplifier is stable and efficient into. Arc's published range runs from 0.65 gross minimum to 1.1 gross maximum; the minimum pushes Qtc higher with no meaningful height savings, and the maximum adds cabinet height for roughly 2 Hz.
Down Fire 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.
Double Baffle, Flush Recess
The front baffle is 1.5 inches, two bonded 3/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3/4 inch of internal clearance.
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.
Perimeter Cross-Brace
A perimeter cross-brace ties the long spans together on a 30 by 15 inch panel. Arc's own manual makes the point that energy lost to panel flex is energy not converted to sound, which is exactly what this construction prevents. Polyfill is pre-installed.
Down Fire and Cabin Gain
The driver fires down into the floor and the cabinet couples to the surface it sits on. A sealed rolloff is gradual, 12 dB per octave below the corner frequency, and it meets rising cabin gain on the way down. Arc's own documentation notes that cabin gain adds roughly 12 dB per octave below 50 Hz in most vehicles. With a 27 Hz Fs this driver has the low end capability to take advantage of that, so in-car response extends well below the anechoic figure.
Power and Warranty
Arc rates the A10 at 250 watts RMS continuous with 500 watts musical. Their documentation is direct about what happens above that: sustained operation beyond the RMS rating will burn the voice coil, and that damage is treated as abuse rather than a warranty claim. Arc also notes that underpowering carries no risk, but a small amplifier driven into clipping does. Feed it clean, unclipped power in the 200 to 250 watt range.
Both variants are dual voice coil, so final impedance is set at the driver. Drivers mount to 8/32 threaded inserts with stainless machine screws, included. The enclosure carries a 1 year limited warranty. Bring your own A10D2 or A10D4; the driver is purchased separately.
Cut for the Driver, Not the Catalog
One driver, one volume, one set of machine files. Cut, assembled and inspected one at a time in Tullahoma, Tennessee.
| Series | Proline X Performance Optimized Down Fire |
| Compatible Driver | Arc Audio A10D2 (DVC 2Ω) or A10D4 (DVC 4Ω) |
| Enclosure Type | Sealed | Down Fire Geometry | Floor-Coupled |
| Firing Direction | Down Firing, Driver Fires Toward Floor |
| External Width | 30 Inches |
| External Depth | 15 Inches |
| External Height | 6.25 Inches |
| Dimension Reference | All External Dimensions Measured In Down Fire Position |
| Internal Volume (Gross) | 0.859 Cubic Feet, Matches Arc's Optimum Sealed Spec of 0.85 Gross |
| Internal Volume (Net) | ~0.80 Cubic Feet |
| Arc Published Sealed Range | 0.65 Min / 0.85 Optimum / 1.1 Max (All Gross) |
| Target System Qtc (A10D4) | 0.854 |
| Predicted F3 (A10D4) | 39.0 Hz |
| Driver Fs | 26.995 Hz (Both Variants) |
| Driver Qts | 0.477 (D2) / 0.506 (D4) |
| Driver Qes / Qms | 0.511 / 7.155 (D2) | 0.547 / 6.744 (D4) |
| Driver Vas | 40.41 Liters (D2) / 41.82 Liters (D4) |
| Driver BL | 13.766 T (D2) / 18.090 T (D4) |
| Driver Mms | 146.54 g (D2) / 141.59 g (D4) |
| Driver Re | 3.9 Ohms (D2) / 7.466 Ohms (D4) |
| Driver Xmax (One-Way) | 8mm |
| Driver Sensitivity | 85.4 dB (1W/1m) |
| Driver Power Handling | 250 Watts RMS / 500 Watts Musical |
| Mounting Depth Required | 3.77 Inches (Arc Spec) |
| Woofer Opening | 9.06 Inches (Arc Spec) |
| Standoffs | None |
| Material | Langboard Elite 3/4" MDF |
| Joinery | V-Groove and Dado (CNC-Cut) |
| Construction | ShopSabre CNC / Perimeter Cross-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 |
| Carpet Finish | Plush Black |
| Bundle Options | Enclosure Only (Bring Your Own A10D2 or A10D4) |
| Weight | 28 lb |
| 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
0.80 cu ft against a 40.4 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 12.76 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 27.00 | Hz | free-air resonance |
| Qts | 0.477 | D4 | |
| Vas | 40.41 | L | equivalent compliance |
| Sd | 346.4 | cm² | effective piston area |
| Xmax | 12.76 | mm | Cms 50%, ResoNix Klippel; Arc publishes 8 mm |
| Pe | 250 | W | continuous RMS |
| SPL | 83.8 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by Arc Audio A-Series, store record + ResoNix Klippel for Xmax. 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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