Proline X PO 10D-S DFW CompRT sealed down-fire wide enclosure for two Kicker CompRT, 41 inches wide by 9.5 inches tall, feet add 1.75 inches of height.

Proline X PO 10D-S DFW CompRT sealed down-fire wide enclosure, end panel with side-mounted terminal cup, 9.5 inches tall by 12 inches deep.

Proline X

Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure | Kicker CompRT

Q: Why is this dual cabinet 41 inches wide instead of 30?

Because it is only 12 inches deep. The standard Performance Optimized Down Fire cabinet for the Kicker CompRT is 30 wide by 15 deep, and this version is for spaces 3 inches shallower than that, under a rear bench or on a narrow cargo floor.Airspace has to come from somewhere. Losing depth means recovering it along the length, so the cabinet runs 41 inches long and stands 9.5 inches tall. If you have 15 inches of depth, the standard cabinet is shorter in length and is the better pick; if you have 12 inches of depth and 41 inches of run, this is the shape that works.

Q: How does this compare to the standard 30 x 15 Kicker CompRT enclosure?

Same driver, different shape. The standard cabinet is 30 by 15 by 10.125 inches and was built to 0.793 cubic feet net per chamber. This cabinet is 41 by 12 by 9.5 inches and holds 0.798 cubic feet net per chamber.The airspace is essentially the same, within about a hundredth of a cubic foot, so the two behave the same way. The choice is about the space you have: the standard box is deeper and shorter in length, this one is long and shallow.

Q: Why two separate chambers instead of one shared volume?

Because two drivers in a shared sealed volume interact acoustically. Each driver's compression phase becomes the pressure environment the other driver is working against, which smears transient response and blurs the alignment each would have on its own.A full-height bonded 3/4 inch MDF divider eliminates that. Each CompRT gets its own 0.798 cubic feet net and its own polyfill, and the 48CWRT104 produces its own sealed alignment at Qtc 0.923 in each chamber. Separate chambers are the standing design rule on every Proline X dual sealed enclosure.

Q: Where do the Thiele-Small figures on this page come from?

For the 48CWRT104, Klippel measurement, not a datasheet summary. That is why this page lists Cms, Bl, Mms, Sd, Qes and Qms alongside the usual Fs, Qts and Vas. The alignment was computed directly from those values: Qtc 0.923, Fc 48.2 Hz, F3 39.5 Hz per chamber.The dual 2 ohm 48CWRT102 figures come from a library parameter set (Fs 28.7 Hz, Qts 0.4865, Vas 35.36 L), not from Klippel data, and give Qtc 0.779, Fc 46.0 Hz, F3 42.1 Hz. Treat those as a guide to a few hundredths.

Q: How is this enclosure wired, and how do I set my final impedance?

The enclosure uses one side-mounted Proline X terminal cup with a single pair of posts, pre-wired in 12 gauge OFC to both driver positions in parallel. You do not wire the two chambers separately at the amplifier.Final impedance is set at the drivers. Each 48CWRT104 is dual 4-ohm, so how you wire the two coils on each driver determines the load the amplifier sees through the cup. Wire both drivers identically, since mismatched wiring between chambers splits power unevenly, and confirm the load against your amplifier's minimum stable impedance.

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

Side mounted, and there is one cup serving both driver positions rather than one per chamber. 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 accessible with the enclosure in its installed position, since both baffles face 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 keeps both chambers airtight under sustained pressure cycling. The chamber divider is a full-height bonded 3/4 inch panel, which also ties the front and rear walls together across the 41 inch span. 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, at both driver positions. Polyfill is installed in each chamber as a light wall lining. Assembled and inspected in Tullahoma, Tennessee.

Q: Are the Kicker CompRT subwoofers included with this enclosure?

No. This listing is for the enclosure only. Bring your own pair of Kicker 48CWRT104 subwoofers. The cutouts and mounting depth are direct fit for the 48CWRT104, and the feet ship uninstalled in the box.

SKU: PO 10D-S DFW CompRT

QUICK SPECS

Alignment: 0.798 cu ft net per chamber, 1.596 cu ft net total. 48CWRT104: Qtc 0.923, Fc 48.2 Hz, F3 39.5 Hz (Klippel T/S). 48CWRT102: Qtc 0.779, Fc 46.0 Hz, F3 42.1 Hz (library T/S)
Down Fire Wide: 41 in W x 12 in D x 9.5 in H measured in down fire position, sized for under the rear seat of a truck or SUV
Chambers: Two fully separate sealed chambers, 3/4 in MDF full divider, one shared side-mounted terminal cup
Drivers: Pair of Kicker 48CWRT104 CompRT 10 (DVC 4Ω), 400W RMS each, 13.35mm linear excursion, 3.4375 in top-mount depth
Wiring: One cup feeds both positions in parallel, impedance set at the drivers, wire both identically
Build: V-groove and dado joinery, double-layer 1.5 in front baffle, full divider, side-mounted 12g OFC terminal cup, feet ship uninstalled (+1.75 in)

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.

$ 349.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure | Kicker CompRT

$ 349.99

More enclosures cut for Kicker subwoofers: Kicker Subwoofer Boxes

Enclosure Type Sealed

External Dimensions 41" W x 12" D x 9.5" H (measured in down fire position, excludes standoffs)

Gross Volume 1.70 cu ft

Net Volume 1.596 total / 0.798 per chamber cu ft

Shipping Weight 47.8 lbs

Front Panel Thickness 1.5"

INSTALLER'S TAKE

Same CompRT pair, turned sideways. The standard 30 by 15 needs 15 inches of depth; this one needs 12 and 41 inches of run, which is what the space under most rear benches actually gives you.

The CompRT is the shallow I have recommended most often over the years, and the Klippel data explains why. A 32.3 Hz free-air resonance on a driver with a 3-7/16 inch mounting depth is not normal, and a Qts of 0.618 means it has real options in a sealed box rather than being locked into an underdamped alignment.

At 0.798 net per chamber the 48CWRT104 lands at Qtc 0.923, Fc 48.2 Hz, F3 39.5 Hz. Slightly above unity, a modest lift at the corner and the composed, controlled character the CompRT is known for. If you are running the dual 2 ohm 48CWRT102, the library parameters put it at Qtc 0.779, Fc 46.0 Hz, F3 42.1 Hz in the same box.

Height is 9.5 inches, set by the airspace. The motor clears the top panel by 5.312 inches, so there was room to spare. Add 1.75 for the feet and plan around 11.25 inches installed.

Wire both drivers identically at the coils. One cup, fed in parallel to both positions. Target 300 to 400 watts RMS per driver.

Product Details

Proline X Performance Optimized Down Fire Wide Dual 10" Sealed

Under rear seat fitment for trucks and SUVs. Cut and tuned for a pair of Kicker CompRT 10s, model 48CWRT104

Down Fire WideV-Groove and Dado12" Shallow DepthSeparate ChambersKlippel Measured T/S

0.798cu ft net per chamber

0.923system Qtc per chamber, 48CWRT104

39.5 HzF3 rolloff, 48CWRT104

9.5 incabinet height

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 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 9.5 inches tall, measured in the down fire position. It is cut for the same Kicker CompRT 10 pair as our standard box, 3 inches shallower front to back and 11 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 15 inches of depth, the standard 30 by 15 inch cabinet at 10.125 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 11.25 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 cutout and the cabinet height all come from the Kicker CompRT 10's own measured numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.

Built Around a Pair of Kicker CompRT 10s

Nothing about this cabinet is generic. Both baffle positions are bored to Kicker's 9.125 inch mounting hole specification, and the round 10.6875 inch frame sits on the 12 inch deep baffle with material fore and aft. The cabinet height is solved around the driver's 3.4375 inch top mount depth, with 5.312 inches clear above the motor, so airspace set the height here, not clearance.

The 48CWRT104 is a dual 4 ohm shallow mount rated 400 watts RMS. It uses an injection molded polypropylene cone, a Santoprene rubber surround with Kicker's red double stitching, the SoloKon integrated cone to backplate design, and Forced-Air Cooling that runs the motor roughly 20 percent cooler. The cone and surround are UV resistant, which is why this driver shows up in UTV and open cab builds as often as it does in trucks.

The Thiele-Small data this enclosure is cut from comes from Klippel measurement rather than a datasheet estimate: Fs 32.3 Hz, Qts 0.618, Vas 27.80 liters, Bl 19.158 Tm, Mms 150.85 g, Sd 349.67 cm², and 13.35mm of linear excursion. A 32.3 Hz free air resonance on a shallow 10 is low, and it is the single parameter that lets a thin driver reach like a full depth one.

Two Chambers, Not One

This enclosure follows the Proline X standing design rule for dual sealed builds: two fully separate chambers divided by a bonded full-height 3/4 inch MDF panel.

Two drivers sharing one sealed volume interact acoustically. Each driver's compression phase becomes the pressure environment the other is working against, which smears transient response and blurs the alignment each would have on its own. A full divider eliminates that. Each CompRT gets its own 0.798 cubic feet net and its own polyfill, and on a 41 inch cabinet the divider ties the front and rear walls together mid span.

Net Volume, Not Gross

Total gross volume is 1.696 cubic feet. After the divider and displacement, each chamber nets 0.798 cubic feet, 1.596 net total, within a hundredth of a cubic foot of the 0.793 our standard 30 by 15 dual CompRT was built to.

Kicker publishes a sealed range for the CompRT 10 in cubic feet, 0.4 minimum to 1.25 maximum, and this airspace sits in the middle of it. In it the 48CWRT104 lands at Qtc 0.923, Fc 48.2 Hz, F3 39.5 Hz per chamber: a controlled alignment just above unity, with a modest lift near the corner frequency and the composed character the CompRT is known for.

For the dual 2 ohm 48CWRT102, calculated from a library parameter set rather than Klippel data (Fs 28.7 Hz, Qts 0.4865, Vas 35.36 L), the same chamber reads Qtc 0.779, Fc 46.0 Hz, F3 42.1 Hz. The mounting figures on this page are the 48CWRT104's; confirm the 48CWRT102's cutout and depth against it before ordering.

Going larger would lower Qtc a little, but on a down fire build meant to disappear under a seat, height is the entire point. Firing down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz, so in car response extends well below the anechoic figure.

True net, not marketing net. Internal volume is calculated from the machined cavity dimensions and the driver's displacement of 0.0334 cubic feet, not estimated from external dimensions minus wall thickness.

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 9.5 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 11.25 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.

Separate Chambers

A bonded full-height 3/4 inch divider gives each driver its own 0.798 cubic feet net and its own polyfill, and ties the walls together mid span.

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 in each chamber. It controls internal reflections and is not packed to change the acoustic volume.

Power and Wiring

Kicker rates each 48CWRT104 at 400 watts RMS continuous. We recommend 300 to 400 watts RMS per driver on this alignment. Both drivers are dual 4 ohm, and the single cup feeds both positions in parallel, so you set the final impedance at the drivers by how you wire each one's coils. Wire both drivers identically; mismatched wiring between chambers splits power unevenly. Confirm the resulting load against your amplifier's minimum stable impedance.

Mounting hardware is included, two sets of 8/32 threaded inserts with stainless steel machine screws, and polyfill is installed. Bring your own pair of Kicker 48CWRT104 subwoofers; the drivers are purchased separately. The enclosure carries a 1 year limited warranty.

Cut for the Driver, Not the Catalog

Two chambers, one driver each, cut to the CompRT 10's own measured parameters, in a footprint built for the space under a rear bench. Machined on our ShopSabre routers and built one at a time in Tullahoma, Tennessee.

Specifications

Series	Proline X Performance Optimized Down Fire Wide
Compatible Driver	Kicker 48CWRT104 CompRT 10 (DVC 4Ω) \| Pair Required
Enclosure Type	Sealed \| Dual Driver \| Down Fire Geometry \| Floor-Coupled
Chamber Configuration	Two Fully Separate Chambers \| Full Divider \| Single Shared Side-Mounted Terminal Cup
Intended Fitment	Under The Rear Seat Of Trucks And SUVs, Or Narrow Cargo Floors
Firing Direction	Down Firing, Both Drivers Fire Toward The Floor
External Width	41 Inches
External Depth	12 Inches
External Height	9.5 Inches
Installed Height	11.25 Inches With The 1.75 Inch Feet
Dimension Reference	All External Dimensions Measured In Down Fire Position, Excluding Feet
Internal Volume (Gross)	1.696 Cubic Feet Total
Internal Volume (Net)	0.798 Cubic Feet Per Chamber, 1.596 Cubic Feet Total
Kicker Published Sealed Range	0.4 Min / 1.25 Max (Cubic Feet)
48CWRT104 Qtc / Fc / F3 Per Chamber	0.923 / 48.2 Hz / 39.5 Hz (Klippel T/S)
48CWRT102 Qtc / Fc / F3 Per Chamber	0.779 / 46.0 Hz / 42.1 Hz (Library T/S: Fs 28.7 Hz, Qts 0.4865, Vas 35.36 L)
Comparison, Standard 30x15 Dual	30 x 15 x 10.125 In, 0.793 Cubic Feet Net Per Chamber. Same Airspace, Different Shape
Driver Fs	32.3 Hz (Klippel, 48CWRT104)
Driver Qts	0.618 (Klippel)
Driver Qes / Qms	0.6635 / 9.097 (Klippel)
Driver Vas	27.80 Liters (Klippel)
Driver Bl	19.158 Tm (Klippel)
Driver Mms	150.85 g (Klippel)
Driver Cms	0.161 mm/N (Klippel)
Driver Re	7.945 Ohm (Klippel)
Driver Sd	349.67 cm² (Klippel)
Driver Xmax	13.35mm Linear (Klippel)
Driver Displacement	0.0334 Cubic Feet
Voice Coil Configuration	Dual 4-Ohm, Impedance Set At The Drivers, Wire Both Identically
Recommended Power	300-400 Watts RMS Per Driver (Kicker Rated: 400W RMS Continuous)
Mounting Depth	3.4375 Inches Top-Mount (Kicker Spec), 5.312 Inches Clear Above The Motor
Woofer Opening	9.125 Inches (Kicker Spec)
Feet	1.75 Inch, Included, Shipped Uninstalled
Material	Langboard Elite 3/4" MDF
Construction	ShopSabre CNC \| V-Groove and Dado Joinery \| Full-Height Divider
Panel Thickness	3/4 Inch
Front Baffle	Double-Layer 1.5" MDF (Two 3/4" Sheets Bonded), Outer Layer Flush Recess
Corner Profile	Square (Down Fire Series Standard)
Driver Mounting	8/32 Threaded Inserts \| Stainless Steel Machine Screws Included \| 2 Sets
Terminal Cup	Proline X ABS/Carbon Fiber Composite \| Side Mounted \| One Cup
Internal Wiring	12 Gauge OFC, Pre-Wired To Both Driver Positions In Parallel
Damping	Polyfill Installed Per Chamber, Light Wall Lining
Carpet	Plush Black
Bundle Options	Enclosure Only (Bring Your Own Pair Of 48CWRT104)
Warranty	1-Year Limited (Enclosure)
Built In	Tullahoma, Tennessee, USA

Performance Graphs

Net airspace

0.798

cu ft per chamber

System Qtc

0.78–0.92

sealed

Half power

39.5–42.1

Hz · F3

Xmax at

256

W RMS · no filter

With 25 Hz subsonic

317

W RMS · +24%

Amplifier

200–400

W RMS recommended

This enclosure holds 0.798 cu ft net per chamber. In it the Kicker CompRT 10 (48CWRT102) runs a system Qtc of 0.78–0.92 with half power at 39.5–42.1 Hz, and the cone reaches its 13.35 mm travel limit at 256 W, below the driver’s 400 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 317 W — +61 W, or 24 percent more power for the same 13.35 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 48.7–56.8

D2 · EBP 56.8D4 · EBP 48.7

The CompRT 10 (48CWRT102) straddles the boundary at 48.7–56.8 depending on coil — part sealed-band, part transition. Either way it takes a sealed load happily; the coil you run shifts the alignment more than it shifts this verdict.

02What the box does to it

0.798 cu ft against a 35.4 L Vas.

α = Vas ÷ Vb = 1.56 · Fc = Fs√(α+1) = 46–48 Hz · Qtc = 0.78–0.92

D2 · Qtc 0.78, Fc 46 Hz, F3 42.1 HzD4 · Qtc 0.92, Fc 48 Hz, F3 39.5 Hz

The box lifts resonance from 28.7 Hz free-air to 46–48 Hz and half power lands at 39.5–42.1 Hz, anechoic, before any cabin gain. This enclosure ships without a driver, so both coil variants the maker offers are plotted. They do not load the same box the same way.

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

P_Xmax = 256–311 W unfiltered → 317–336 W with a 25 Hz subsonic

D2 · 256 W, no filterD4 · 311 W, no filterD2 · 317 W with subsonic at 25 Hz, 24 dB/octD4 · 336 W with subsonic at 25 Hz, 24 dB/octXmax 13.35 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 13.35 mm. Unfiltered that is 256 W, reached first at 20 Hz. It sits under the 400 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 317 W before hitting the same 13.35 mm. That is 24 percent more amplifier for the price of one filter setting.

Param	Value	Unit	Note
Fs	28.70	Hz	free-air resonance
Qts	0.486 / 0.618		D2 / D4
Vas	35.36 / 27.80	L	equivalent compliance
Sd	349.7	cm²	effective piston area
Xmax	13.35	mm	one-way linear travel
Pe	400	W	continuous RMS
SPL	84.0	dB	1 W / 1 m, derived from T/S

Driver parameters as published by Kicker published Klippel T/S sheet. 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.