Proline X PO 12-S DF MP sealed down-fire enclosure, 30 inches wide by 8.1 inches tall, feet add 1.75 inches. Optimized for Hertz MP.

Proline X PO 12-S DF MP sealed down-fire enclosure, front baffle with a single flush-mount cutout, 30 by 15 inches. Optimized for Hertz MP.

Proline X PO 12-S DF MP sealed down-fire enclosure, three-quarter view of the flush-mount baffle opening and side terminal cup. Optimized for Hertz MP.

Proline X PO 12-S DF MP sealed down-fire enclosure, end panel with recessed terminal cup, 8.1 inches deep by 15 inches tall. Optimized for Hertz MP.

Proline X

Performance Optimized Down Fire Sealed 12" Enclosure | Hertz Mille Pro MP 300

Q: Why is this enclosure larger than Hertz's recommended 28 liters?

Because the driver's mounting depth sets the minimum cabinet height. The MP 300 mounts 6.46 inches deep. Our double baffle recovers 0.75 inches since the outer layer is a flush recess and the driver bolts to the inner layer, and a 3/8 inch milled relief behind the magnet recovers a little more. With half an inch of clearance behind the motor the minimum internal height is 5.875 inches, which works out to 1.10 cubic feet net.The extra volume helps. Hertz publishes Qtc 0.82 at their 28 liter figure. At the 31 liters this cabinet provides, the system lands at Qtc 0.771 with F3 at 40.7 Hz. Better damped with a gentler corner and no meaningful loss anywhere.

Q: Why is 86 dB sensitivity significant?

Because sensitivity determines how much output you get per watt. Most subwoofers in this category sit in the low to mid 80s, and high-excursion shallow drivers frequently drop to 81 or 82 dB as a tradeoff for their motor design. At 86 dB the MP 300 is among the most efficient drivers in the Proline X Down Fire line.In practical terms a 4 dB sensitivity advantage means roughly two and a half times the acoustic output from the same amplifier power. You can reach your target output on a smaller amplifier, or reach it with headroom to spare on a large one, which reduces thermal stress on the driver over long listening sessions.

Q: Do you offer a dual 12 inch MP 300 enclosure?

No, and the reason is worth explaining. The MP 300 has 74 liters of Vas and wants close to a cubic foot of net airspace per driver for a good alignment. In a dual chamber cabinet the footprint is split in half, so all of that volume has to come from height instead.Running the numbers, a dual MP 300 down fire enclosure would need to stand over 11 inches tall to reach even 0.80 cubic feet per chamber, and building it shorter pushes Qtc past 1.0 which produces a peaky, poorly controlled alignment. Two single enclosures deliver better sound in a more usable form factor. Drivers with a smaller Vas, like the Mille Pro MPS series, work well as duals in this format.

Q: How do I wire this enclosure and set my impedance?

The enclosure has one side-mounted Proline X terminal cup pre-wired in 12 gauge OFC. Final impedance is set at the driver, and it depends on which version you buy.The MP 300 D2.3 has dual 2-ohm coils: parallel gives 1 ohm, series gives 4 ohms. The MP 300 D4.3 has dual 4-ohm coils: parallel gives 2 ohms, series gives 8. Hertz rates the driver at 600 watts RMS. Confirm your amplifier is stable at your chosen load before powering the system.

Q: How does the MP 300 compare to the 10 inch MP 250?

The 12 is more efficient and has more cone area; the 10 has a slightly lower F3 in its cabinet. The MP 300 measures 86 dB sensitivity against the MP 250's 83.4, which is a substantial real-world difference, and it has a lower free-air resonance at 24 Hz against 30 Hz.In their respective enclosures the 10 reaches F3 39.4 Hz at Qtc 0.741 and the 12 reaches 40.7 Hz at Qtc 0.771, so the 10 edges it on paper. But the 12 moves far more air and gets louder on less power. Both share the same 600 watt rating and 17mm of excursion. Cabinet heights are 7.4375 inches for the 10 and 8.125 for the 12.

Q: Where is the terminal cup located on a down fire enclosure?

Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup regardless of alignment, whether standard, wedge, or down fire. On this cabinet that keeps the connection fully accessible with the enclosure in its installed position, since the baffle faces the floor. The cup is our Proline X ABS and carbon fiber composite unit, recessed, with stainless hardware, copper ring terminals, and pre-wired 12 gauge OFC.

Q: How is this enclosure built?

V-groove and dado joinery, CNC-cut on ShopSabre routers from Langboard Elite MDF. Every panel joint is a machined interlocking groove that mechanically locks the panels before adhesive is applied, which is what keeps the cabinet airtight under sustained pressure cycling.The front baffle is a double layer at 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 and matters with an 11.30 inch cutout. A 3/8 inch relief is milled into the opposite panel behind the magnet. Perimeter cross-bracing and pre-installed polyfill complete the build. Assembled and inspected in Tullahoma, Tennessee.

Q: Is the Hertz MP 300 subwoofer included with this enclosure?

No. This listing is for the enclosure only. Bring your own Hertz Mille Pro MP 300 D2.3 or MP 300 D4.3. The cutout, mounting depth and magnet clearance are all cut specifically for this driver.

SKU: PO 12-S DF MP

QUICK SPECS

Alignment: 1.10 cu ft net, Qtc 0.771, Fc 44.1 Hz, F3 40.7 Hz, better damped than Hertz's published 0.82 at their 0.99 cu ft figure
Driver: Hertz MP 300 D2.3 or D4.3, 600W RMS / 1200W peak, 17mm Xmax, 24 Hz Fs, 86 dB sensitivity, 6.46" mounting depth
Fitment: 287mm / 11.30" cutout, 3/8" milled magnet relief, double-layer 1.5" front baffle with flush outer recess
Build: Proline X V-groove and dado joinery, perimeter cross-brace, 12g OFC side-mounted terminal cup
Cabinet: 30"W x 15"D x 8.125"H measured in down fire position, square corners

Shipping Included No freight charges at checkout. What you see is what you pay.

Built in Tennessee CNC cut from 3/4" Langboard Elite MDF. V-groove and dado joinery.

Advanced Terminal Cup Built in-house. ABS/Carbon Fiber. Stainless steel hardware. Copper ring terminals.

$ 269.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Performance Optimized Down Fire Sealed 12" Enclosure | Hertz Mille Pro MP 300

$ 269.99

Enclosure Type Sealed

External Dimensions 30" W x 15" D x 8.125" H (measured in down fire position)

Gross Volume 1.31 cu ft

Net Volume 1.10 cu ft

Weight 35 lbs

Front Panel Thickness 1.5"

INSTALLER'S TAKE

86 dB sensitivity. That is the number to pay attention to on this driver. Most subwoofers in this program sit in the low to mid 80s and several drop to 81 or 82, which means they need real amplifier power just to keep up. The MP 300 gets meaningfully louder on the same watts.

Pair that with a 24 Hz free-air resonance and 74 liters of Vas and you have a driver with genuine capability rather than a spec sheet built for a price point. Qts of 0.42 is low enough to reach a properly damped sealed alignment.

Hertz recommends 28 liters and this cabinet gives 31, because the 6.46 inch mounting depth sets the floor on internal height. That extra volume moves Qtc from their published 0.82 down to 0.771, which is the right direction. Worth noting their published figures reconcile with their own T/S: run their numbers at their own 28 liter volume and you get 0.80 against a published 0.82. Close enough that I trust the rest of the sheet.

The V-cone profile is the real thing rather than styling. Pressing paper pulp with mineral powder injection is the same process Hertz uses on Mille Legend, and the profile keeps the cone acting like a piston instead of flexing at the edge under load. 65mm four-layer CCAW coil on a vented former, high-density ferrite motor, BL of 12.

17mm of linear excursion with 27mm of mechanical travel before damage. 600 watts RMS. At 86 dB you do not need to chase the rating to get where you want to be.

One honest note: we do not offer a dual 12 in this driver. The MP 300 wants close to a cubic foot per chamber, and on a halved footprint that volume has to come entirely from height, which pushes the cabinet past 11 inches. Two singles is the better build.

Product Details

Proline X Performance Optimized Down Fire 12" Sealed

Cut and tuned for the Hertz Mille Pro MP 300

V-Groove and DadoLangboard Elite MDF1.10 cu ft Net86 dB Sensitivity

1.10cu ft net

0.771system Qtc

40.7 HzF3 rolloff

8.125 incabinet height

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 Hertz Mille Pro MP 300's own published numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.

Built Around the Hertz MP 300

Nothing about this cabinet is generic. The baffle is bored to the MP 300's 287mm cutout, 11.30 inches, and the internal height is set by its 6.46 inch mounting depth. The driver bolts to 8/32 threaded inserts with stainless machine screws included, and at 8.63 kg it is a heavy motor that wants a baffle it can actually pull against.

The driver underneath is a genuinely capable foundation for a sealed 12: a 24 Hz free-air resonance, 74 liters of Vas, and a Qts of 0.42 that is low enough to reach a properly damped sealed alignment. Effective cone diameter is 260mm.

The construction is classic Hertz. The cone is a V-cone profile pressed from paper pulp with mineral powder injection, the same technique used on the flagship Mille Legend line, so the diaphragm behaves like a piston rather than flexing at the edge under load. The surround is high-purity IIR butyl rubber. A 65mm four-layer CCAW voice coil sits on a vented TIL-P former, driven by a compact high-density ferrite motor with a BL of 12 T/m, all carried in a six-spoke aluminum alloy basket vented under the spider. Excursion is 17mm linear with 27mm of mechanical travel before damage.

One clarification if you are cross shopping our Hertz cabinets: the Mille Pro MPS series is the shallower line and gets its own cabinets. This page is cut for the Mille Pro MP 300 only.

Net Volume, Not Gross

We build this cabinet at 1.10 cubic feet net against 1.26 gross. Hertz publishes 28 liters, or 0.99 cubic feet, as the recommended sealed volume, and this cabinet runs slightly larger because the driver's 6.46 inch mounting depth sets the floor on internal height. With the flush recess outer baffle layer and a milled magnet relief both recovering clearance, the minimum internal height still works out to 5.875 inches.

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 extra volume lands in your favor. Computed from Hertz's published Fs of 24 Hz, Qts of 0.42 and Vas of 74 liters, this cabinet reaches Qtc 0.771 with Fc at 44.1 Hz and a predicted F3 of 40.7 Hz. Hertz publishes Qtc 0.82 and Fb 48 Hz at their own 28 liter figure. Better damped, gentler corner, no meaningful loss anywhere.

Worth saying plainly: Hertz's published enclosure data reconciles with their own Thiele-Small parameters, which is less common in this category than it should be. Running their numbers independently at their own 28 liters produces Qtc 0.80 against a published 0.82.

The MP 300 D2.3 and MP 300 D4.3 share the same Thiele-Small set, so the alignment above applies to both. The difference is coil impedance, which you set at the driver, not a difference in enclosure behavior.

Firing down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz, so in-car response extends below the anechoic figure.

Down Fire Construction

Cut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3/4 inch MDF. Every panel joint is a machined interlocking groove that mechanically locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Perimeter cross-bracing ties the panels together and polyfill is pre-installed. Corners are square on Down Fire cabinets.

External dimensions are 30 inches wide by 15 inches deep by 8.125 inches tall, measured in the down fire position. The driver fires down into the floor, and the finished weight is 34 pounds.

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, which matters with an 11.30 inch cutout.

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.

Milled Magnet Relief

A 3/8 inch deep relief is machined into the panel opposite the baffle, directly behind the magnet, so the MP 300's motor gets its clearance without adding cabinet height.

Power and Warranty

Hertz rates the MP 300 at 600 watts RMS and 1200 watts peak, and sensitivity is 86 dB at 1W/1m, among the most efficient drivers in the Down Fire line. Most subwoofers in this category sit in the low to mid 80s, so the MP 300 reaches a given output on less amplifier power, which also reduces thermal stress over long sessions.

Both versions are dual voice coil, so final impedance is set at the driver: the D2.3 gives 1 ohm in parallel or 4 ohms in series, the D4.3 gives 2 ohms in parallel or 8 in series. Confirm your amplifier is stable at your chosen load before powering the system.

The enclosure carries a 1 year limited warranty. Bring your own Hertz Mille Pro MP 300 D2.3 or MP 300 D4.3; the driver is purchased separately. The cutout, mounting depth and magnet clearance are all cut for that driver specifically.

Cut for the Driver, Not the Catalog

One driver, one set of published parameters, one cabinet machined to match them. Built one at a time in Tullahoma, Tennessee.

Specifications

Series	Proline X Performance Optimized Down Fire
Compatible Driver	Hertz Mille Pro MP 300 D2.3 or MP 300 D4.3
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	8.125 Inches
Dimension Reference	All External Dimensions Measured In Down Fire Position
Internal Volume (Gross)	1.26 Cubic Feet
Internal Volume (Net After Displacement)	1.10 Cubic Feet
Hertz Recommended Sealed Volume	28 Liters / 0.99 Cubic Feet (See FAQ On Why This Cabinet Is Larger)
Target System Qtc	0.771 (Hertz Publishes 0.82 At Their Volume)
Predicted Fc	44.1 Hz (Hertz Publishes Fb 48 Hz At Their Volume)
Predicted F3	40.7 Hz
Driver Fs	24 Hz
Driver Qts	0.42
Driver Qes / Qms	0.45 / 5.9
Driver Vas	74 Liters / 2.613 Cubic Feet
Driver Re	1.9 Ohm
Driver Le	1.6 mH
Driver BL	12 T/m
Driver Effective Diameter	260mm
Driver Xmax	17mm Linear
Driver Xmech	27mm Before Damage
Driver Sensitivity	86 dB (1W/1m), Among The Most Efficient In The Down Fire Line
Driver Power Handling	600 Watts RMS / 1200 Watts Peak
Driver Voice Coil	65mm CCAW \| 4-Layer \| Vented TIL-P Former
Driver Cone	V-Cone Profile \| Pressed Paper Pulp with Mineral Powder Injection
Driver Surround	High-Purity IIR Butyl Rubber
Driver Motor	High-Density Ferrite \| Compact High-Performance Design
Driver Basket	Six-Spoke Aluminum Alloy with Vents Under Spider
Driver Weight	8.63 kg
Mounting Depth Required	6.46 Inches (Hertz Spec)
Woofer Opening	287mm / 11.30 Inches (Hertz Spec)
Standoffs	Not Required On This Build
Material	Langboard Elite 3/4" MDF
Construction	ShopSabre CNC / Perimeter Cross-Brace
Joinery	V-Groove and Dado (CNC-Cut)
Panel Thickness	3/4 Inch
Front Baffle Construction	Double-Layer 1.5" MDF \| Outer Layer Flush Recess, Driver Mounts To Inner Layer
Magnet Relief	3/8" Deep Milled Relief In Opposite Panel
Corner Profile	Square (Down Fire Series Standard)
Driver Mounting	8/32 Threaded Inserts \| Stainless Steel Machine Screws Included
Voice Coil Configuration	Dual Voice Coil, Impedance Set At The Driver
Terminal Cup	Proline X ABS/Carbon Fiber Composite \| Side Mounted \| 12g OFC Pre-Wired
Internal Wiring	12 Gauge OFC
Damping	Polyfill Pre-Installed
Carpet Finish	Plush Black
Weight	34 lb
Bundle Options	Enclosure Only (Bring Your Own Hertz MP 300)
Warranty	1-Year Limited (Enclosure)
Built In	Tullahoma, Tennessee, USA

Performance Graphs

Net airspace

1.10

cu ft per chamber

System Qtc

0.77

sealed

Half power

40.7

Hz · F3

Xmax at

578

W RMS · no filter

With 25 Hz subsonic

744

W RMS · +29%

Amplifier

600

W RMS recommended

This enclosure holds 1.10 cu ft net per chamber. In it the Hertz Mille Pro MP 300 runs a system Qtc of 0.77 with half power at 40.7 Hz, and the cone reaches its 17.0 mm travel limit at 578 W, below the driver’s 600 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 744 W — +166 W, or 29 percent more power for the same 17.0 mm of travel.

01Is it a sealed driver?

Efficiency bandwidth product places the motor before anything else is decided.

EBP = Fs ÷ Qes = 53.3

D4 · EBP 53.3

At 53.3 the MP 300 sits in the transition band, not the sealed band. That is not a mismatch: a transition motor works in either alignment, and sealed buys a smaller box and a gentler roll-off at the cost of some low-end output. Stage 02 shows what this airspace actually does with it.

02What the box does to it

1.10 cu ft against a 74.0 L Vas.

α = Vas ÷ Vb = 2.38 · Fc = Fs√(α+1) = 44 Hz · Qtc = 0.77

D4 · Qtc 0.77, Fc 44 Hz, F3 40.7 Hz

The box lifts resonance from 24.0 Hz free-air to 44 Hz and half power lands at 40.7 Hz, anechoic, before any cabin gain.

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 17.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

P_Xmax = 578 W unfiltered → 744 W with a 25 Hz subsonic

D4 · 578 W, no filterD4 · 744 W with subsonic at 25 Hz, 24 dB/octXmax 17.0 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 17.0 mm. Unfiltered that is 578 W, reached first at 20 Hz. It sits under the 600 W the driver can take thermally, so the enclosure sets the ceiling, not the voice coil. The dashed traces are the same driver behind a subsonic filter at 25 Hz, 24 dB/oct: stopping the cone wasting travel below the passband lets it take 744 W before hitting the same 17.0 mm. That is 29 percent more amplifier for the price of one filter setting.

Param	Value	Unit	Note
Fs	24.00	Hz	free-air resonance
Qts	0.420		D4
Vas	74.00	L	equivalent compliance
Sd	523.7	cm²	effective piston area
Xmax	17	mm	one-way linear travel
Pe	600	W	continuous RMS
SPL	85.4	dB	1 W / 1 m, derived from T/S

Driver parameters as published by the Hertz Mille Pro pages at hertz-audio.com; the D2 coil is not graphed because Hertz publishes no Xmax for it. Curves computed against this enclosure’s actual net airspace.

Materials

Material

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.

Specifications

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

Internal Bond

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.

Stiffness

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.

Screw Holding

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.

Sourcing

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.