Proline X
Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure | Audiomobile GT2
SKU: PO10D-S DFW AM BO B
- Best For: Under rear seat and narrow cargo floor builds where depth is the constraint
- Configuration: Dual 10" Sealed Down Fire Wide, cut for Audiomobile GT2 2010
- Down Fire Wide: 41"W x 12"D x 8.1875"H, 9.9375" installed on the included feet
- Volume / Alignment: 1.204 ft³ Net common chamber (0.602 per driver), Qtc 1.046, Fc 47.2 Hz, F3 36.4 Hz
- Sonic Character: Punchy, impact-forward, high-output
Financing available. Choose Shop Pay Installments at checkout.
Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure | Audiomobile GT2
Proline X Performance Optimized Down Fire Wide Dual 10" Sealed
Two Audiomobile GT2 2010s, twelve inches deep, firing into the floor. Under rear seat fitment for trucks and SUVs
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 the standard 29.5 by 16 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 8.1875 inches tall, measured in the down fire position. It is cut for the same pair of Audiomobile GT2 2010s as our standard box, 4 inches shallower front to back and 11.5 inches longer. The airspace lost from the depth is recovered along the length, and the height is solved to the driver.
Measure the depth before anything else. Under seat spaces vary widely between cab configurations, and depth is almost always the limiting dimension. If you have 16 inches of depth, the standard 29.5 by 16 inch cabinet at 8.5 inches tall is the pick. If your space stops at 12 inches deep and you have 41 inches of run, this cabinet fits. The feet add 1.75 inches, so the installed height is 9.9375 inches.
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 airspace, the cutouts and the cabinet height all come from the Audiomobile GT2 2010's own numbers and the driver we measured in our shop. A Performance box fits your subwoofer. A Performance Optimized box was built for it.
Built for One Driver, Not for a Size Class
This one is cut to the Audiomobile GT2 2010, a 10 inch driver with 400 watts RMS of power handling, 11.9mm of one way Xmax, and only 4.25 inches of mounting depth. Those numbers are unusual together, and they are what make a cabinet this shallow possible in the first place.
The cutouts are 9.2 inches, matched to the driver's gasket ID, and the round frame sits on the 12 inch deep baffle with material fore and aft. We have the GT2 2010 in the shop: we measured it, built the bolt circle in CAD, and the nutsert locations and the cutouts are machined in the same operation from the same origin on the router, so the holes cannot drift relative to each other.
Internal height under the top panel is 5.9375 inches against the driver's 4.25 inch mounting depth, so the motors clear the top panel by 3.188 inches. Airspace set the height, not clearance.
One Shared Chamber
Unlike most Proline X dual sealed builds, this enclosure uses one common chamber for both drivers, carried over from the standard GT2 2010 design. Both drivers work into the same 1.204 cubic feet net, 0.602 per driver, with internal bracing tying the long walls together across the 41 inch span.
Total gross volume is 1.389 cubic feet. Audiomobile publishes no displacement for the GT2 2010, so the net figure subtracts an estimated 0.088 cubic feet per driver. Audiomobile's own minimum sealed figure sits below this, so the chamber is inside the driver's working range.
Read the Curve Honestly
In this chamber the GT2 2010 pair lands at Qtc 1.046, Fc 47.2 Hz, F3 36.4 Hz, calculated from the published Thiele-Small parameters: Fs 27.5 Hz, Qts 0.61, Vas 33.13 liters.
The GT2 2010 has a Qts of 0.61, which means it cannot reach a textbook 0.707 Qtc in any enclosure that fits in a vehicle; you would need more than five times this airspace per driver. At Qtc 1.046 the response carries a roughly 1.5 dB lift peaking near 64 Hz, with an anechoic F3 of 36.4 Hz. That is an impact alignment, not a flat one.
Loaded into a truck cab or cargo floor and firing down, cabin gain fills in below the knee and the result is a punchy, high output system. If you want a flat sealed alignment above all else, this is not the driver or the enclosure for it.
Keep the gap clear. The 1.75 inch space under the baffle is the air path, not empty room. A toolbox, a jack or a folded blanket pressed against the opening will choke the output. Down fire systems that sound dead almost always have something jammed underneath them.
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 8.1875 inches tall, measured in the down fire position. Feet ship with the enclosure but are not installed; they add 1.75 inches, for an installed height of 9.9375 inches.
1.5 Inch Double Baffle
Two 3/4 inch layers laminated to 1.5 inches, the outer layer machined as a flush recess so the driver bolts to the inner layer, with 8/32 threaded inserts at each driver position. The nutsert pattern is drawn in house from the measured driver.
One Shared Chamber
Both drivers work into one common sealed chamber of 1.204 cubic feet net, with internal bracing tying the long walls together.
One Shared Terminal Cup
Proline X ABS and carbon fiber composite cup with stainless hardware and copper ring terminals, side mounted and pre-wired in 12 gauge OFC to both driver positions in parallel.
Polyfill Installed
Polyfill is installed as a light wall lining. It controls internal reflections and is not packed to change the acoustic volume.
Feet Included
Four ABS and carbon fiber composite feet, machined in house, 1.75 inches of lift, no predrilled holes, so the enclosure is never locked into one orientation. Installed height is 9.9375 inches.
Finish
Plush black carpet. The lasered acrylic badge mounts on the front face rather than the woofer face, so it stays visible in the down fire orientation.
Before You Buy: Read the Impedance
The GT2 2010 runs a single 3 ohm nominal voice coil at 2.8 ohms DCR. This is not a standard car audio impedance and there is no dual 2 ohm or dual 4 ohm version of the driver. Two of them in this enclosure give you exactly two options.
Parallel, 1.5 ohms nominal. Requires a 1 ohm stable monoblock. An amplifier in the 800 to 1000 watt RMS range is the clean match and the configuration we recommend.
Series, 6 ohms nominal. Most amplifiers will drive 6 ohms, but output falls to roughly 40 to 50 percent of the 1 ohm rating. This is the path when your amplifier is not 1 ohm stable.
One side mounted Proline X terminal cup, pre-wired with 12 gauge OFC to both driver positions. Settle the amplifier question before the enclosure ships. The enclosure carries a 1 year limited warranty.
Cut for the Driver, Not the Catalog
Order it as a bare enclosure or loaded with a matched pair of Audiomobile GT2 2010 subwoofers, wired and ready to connect. Every Performance Optimized Down Fire enclosure is built to order in Tullahoma, Tennessee. Questions on fitment or amplifier matching, call 931-563-5151.
| Enclosure Type | Sealed, Down Fire Wide |
| Configuration | Dual 10", common chamber, cut for Audiomobile GT2 2010 |
| External Dimensions | 41" W x 12" D x 8.1875" H, measured in down fire position |
| Overall Height With Feet | 9.9375" |
| Comparison, Standard Down Fire | 29.5" W x 8.5" H x 16" D, built to 0.60 ft³ net per driver. Same airspace, different shape |
| Internal Volume, Gross | 1.389 ft³ |
| Net Internal Volume | 1.204 ft³ total, 0.602 ft³ per driver |
| System Qtc | 1.046 |
| System Resonance (Fc) | 47.2 Hz |
| F3 (anechoic) | 36.4 Hz |
| Feet | Four ABS/Carbon Fiber composite, machined in house, included, no predrilled holes |
| Baffle to Floor Clearance | 1.75" |
| Subwoofer Cutout | 9.2" |
| Driver Mounting Depth | 4.25" required, 3.188" clear above the motor |
| Driver Displacement | 0.088 ft³ per driver, estimated; not published by Audiomobile |
| Driver T/S | Fs 27.5 Hz, Qts 0.61, Vas 33.13 L |
| Front Panel Thickness | 1.5" Double Baffle, outer layer flush recess |
| Panel Thickness | 3/4" (18mm) |
| Material | Langboard Elite MDF |
| Joinery | V-groove and dado, CNC cut on ShopSabre |
| Internal Bracing | Yes, series standard |
| Threaded Inserts | Installed, 8/32 machine screws supplied, pattern drawn in house from measured driver |
| Terminal Cup | Proline X ABS/Carbon Fiber, side mounted, stainless hardware |
| Wiring | Pre-wired 12g OFC to both driver positions |
| Damping | Polyfill installed, light wall lining |
| Carpet | Plush Black |
| Badge | Lasered acrylic, front face mounted |
| Driver Impedance | 3 ohm nominal each (2.8 ohm DCR), single coil |
| System Impedance | 1.5 ohm parallel or 6 ohm series |
| Warranty | 1-Year Limited (enclosure), driver per manufacturer warranty |
| Built In | Tullahoma, Tennessee |
What this cabinet is built from
The cabinet is designed from Audiomobile’s figures taken as printed. This enclosure gives the pair of GT2 2010s 1.204 cubic feet net, 0.60 per driver; its system Q and half-power frequency are on the Specifications tab. If Audiomobile publishes a corrected parameter set, or the driver is measured, the graphs will be modeled and added here.
Driver parameters as published by Audiomobile, from its printed GT2 specification sheet.
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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