Proline X
Performance Optimized Down Fire Sealed Dual 10" Enclosure | Audiofrog GB10
SKU: PO 10D-S DF GB10
- Best For: Dual Audiofrog GB10 Floor-Firing Trunk Builds
- Net Volume: 0.60 cu ft per driver (0.73 cu ft Gross per chamber)
- Alignment: Qtc 0.823 to 0.848, fc 51.6 to 52.6 Hz, F3 44.4 to 46.3 Hz, identical to our wedge version
- Driver Match: Pair of Audiofrog GB10 (matched), GB10D2 or GB10D4
- Impedance: Switch selected, 1 or 4 ohms per driver on the D2, 2 or 8 on the D4
- Construction: Dual Chamber | Down-Firing Sealed | V-Groove/Dado | Double 1.5" Baffle | Threaded Inserts | Feet Included
Financing available. Choose Shop Pay Installments at checkout.
Performance Optimized Down Fire Sealed Dual 10" Enclosure | Audiofrog GB10
Performance Optimized Down Fire | Audiofrog GB10
Dual 10" Sealed Down Fire Enclosure | Floor-Firing Trunk or Cargo Design
Two Audiofrog GB10 Firing Into the Floor
Audiofrog's GB10, a 76 mm coil on a vented cast aluminum basket with a copper pole cap, in two switchable coil versions. The alignment below is computed from Audiofrog's published Thiele-Small parameters, which are carried per coil version rather than shared, because Audiofrog measures each one.
This cabinet holds the same 0.60 cubic feet per driver as our wedge version of the same pair, so the two publish the same Qtc and the same F3. They are the same enclosure in two shapes. Pick the one that fits where the cabinet has to live.
Two Fully Separate Chambers
A full height bonded 3/4 inch MDF divider gives each GB10 its own sealed 0.73 cu ft gross chamber and its own polyfill. Two drivers sharing one volume interact acoustically, each cone's compression stroke becoming the pressure the other works against. A divider removes that entirely.
Why Down Fire
A down fire cabinet sits flat on the trunk or cargo floor with the cones facing down, which keeps the top surface usable and puts the enclosure where a wedge cannot go. It is the answer when there is no rear seat back to lean against, when the load floor has to stay flat, or when the build is a truck rather than a sedan trunk.
Both Cones Fire Downward
The floor becomes the first reflecting surface, which loads the cabin evenly rather than aiming at one seat.
Feet Ship Uninstalled
Mount them to suit your floor, or leave them off and run the cabinet front firing.
Flat Top, Usable Space
A rectangular 30 by 15 inch footprint stacks and straps in a way a wedge cannot.
Flush Recess Baffle
The outer 3/4 inch layer is machined as a recess so each driver bolts to the inner layer, recovering 3/4 inch of internal clearance.
Engineered for the Audiofrog GB10
At 0.60 cubic feet net per driver the Audiofrog GB10 runs a system Qtc of 0.823 to 0.848 with resonance at 51.6 to 52.6 Hz. That is Audiofrog's own recommended sealed volume, 17 liters in their documentation, and theirs is a net figure exactly as ours is. Half power lands at 44.4 to 46.3 Hz anechoic, before any cabin gain.
Alignment Numbers
Qtc 0.823 to 0.848 · fc 51.6 to 52.6 Hz · F3 44.4 to 46.3 Hz anechoic
Mounting Geometry
Both positions CNC cut to 9.2520 in. Mounting depth available is 6.81 in against the 6.260 in the GB10 requires, with 2.05 in of clearance above the motor once the driver is in. Threaded inserts pressed in at every mounting location.
Floor Clearance
At the standard 1.75 inch standoff the gap around each cone works out to 0.95 of the cone's own area. That figure is set by the driver's diameter rather than by this cabinet, and every 10 inch down fire enclosure lands near it. Raising the feet increases it if your floor allows.
Performance Series Construction, Driver-Specific Tuning
Langboard Elite MDF
Premium 3/4 in MDF throughout.
V-Groove and Dado Joinery
CNC cut V-grooves at every panel intersection, sides and divider seated in dados.
Double-Layer 1.5" Baffle
Two bonded 3/4 in MDF sheets, outer layer machined as a flush recess.
Pre-Wired Terminal Cup
One Proline X ABS and carbon fiber composite cup serving both chambers, 12 gauge OFC, side mounted.
Wiring the Pair to Your Amplifier
The GB series does not bring its coils out to the terminals. Each driver carries an impedance selection switch, and the terminal cup wires the two positions in parallel, so the switch alone decides what the amplifier sees. Set both drivers to the HIGH position. A pair of D2 drivers at 4 ohms each presents 2 ohms; a pair of D4 drivers at 8 ohms each presents 4 ohms. Leaving both in the low position halves that again, to 0.5 ohms on a D2 pair, which almost no amplifier is stable into. Set both switches the same way and set them before you mount the drivers, because the switch faces the motor.
Power handling is 1000 watts RMS total across the pair. Aim for roughly 700 to 1000 watts at the impedance you select.
Built in Tennessee, Backed by Audio Intensity
Cut and assembled in Tullahoma, Tennessee on our own CNC equipment. Finished in plush black carpet. 1 year limited warranty. Enclosure only, the drivers are purchased separately. Call 931-563-5151.
Audiofrog GB10 Down Fire: The Wedge Alignment, A Different Shape
0.60 cubic feet net per driver at Qtc 0.823 to 0.848, F3 44.4 to 46.3 Hz, cut direct fit and built to order in Tennessee.
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Down Fire |
| Compatible Driver | Audiofrog GB10, quantity 2. Direct fit |
| Configuration | Dual 10 inch, dual chamber sealed down fire |
| Mounting Position | Trunk or cargo floor, cones firing downward |
| Firing Direction | Downward into the floor. Feet included, uninstalled |
| External Width | 30 in |
| External Depth | 15 in |
| External Height | 9.06 in measured in the down fire position |
| Internal Volume, Gross | 1.46 cu ft total, 0.73 per chamber |
| Internal Volume, Net Acoustic | 1.20 cu ft total, 0.60 per driver |
| Alignment | Qtc 0.823 to 0.848, fc 51.6 to 52.6 Hz, F3 44.4 to 46.3 Hz anechoic |
| Driver Cutout | 9.2520 in |
| Driver Mounting Depth | 6.81 in available, 6.260 in required by the driver |
| Floor Slot Ratio | 0.95 at the standard 1.75 in standoff |
| Power Handling | 1000 watts RMS total across the pair |
| Impedance | Switch selected on the driver. D2 selects 1 or 4 ohms, D4 selects 2 or 8 |
| Xmax | 17.6 mm one way on the D2, 19 mm on the D4 |
| Material | Langboard Elite MDF |
| Construction | CNC cut, V-groove and dado joinery |
| Panel Thickness | 0.75 in |
| Baffle | 1.5 in, double layer, outer layer machined as a flush recess |
| Internal Bracing | Full chamber divider |
| Driver Mounting | Threaded inserts at every mounting location, stainless machine screws included |
| Terminal Cups | One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC |
| Feet | Included, uninstalled |
| Damping | Light polyfill wall lining, does not alter acoustic volume |
| Carpet | Plush black |
| Weight | 36.8 lb |
| 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
0.60 cu ft against a 30.0 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 17.6 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 31.00 / 32.00 | Hz | free-air resonance |
| Qts | 0.510 / 0.500 | D2 / D4 | |
| Vas | 30.00 / 29.00 | L | equivalent compliance |
| Sd | 346.3 | cm² | effective piston area |
| Xmax | 17.6 | mm | one-way linear travel, D2 coil. The D4 coil is rated 19 mm on the same cone; the smaller figure is plotted so the power shown is conservative for both. |
| Pe | 500 | W | continuous RMS |
| SPL | 84.0 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by audiofrog.com and the GB Series Subwoofer 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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