Proline X PO 12D-S W W1V3 sealed wedge, front baffle with gloss black insert and pre-wired leads, 32 by 16 inches.

Proline X

JL Audio 12W1v3 Dual Box: Sealed 12" Wedge Enclosure

Q: Does this fit the JL Audio 12W1v3, and will any other 12 inch fit?

The 12W1v3, yes, in both the 2 ohm and the 4 ohm version. The baffle is cut to 11.0625 in, JL's published mounting hole, under the 12.5 in frame. The 5.41 inch motor clears the cabinet with 3.73 inch to spare. Run two of the same coil so the chambers match.Any other 12, no. The airspace is engineered around the 12W1v3's own Qts and Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

Q: What amplifier power should I run, and how should I wire it?

JL rates the 12W1v3 at 300 watts RMS per driver, so target 210 to 300 watts RMS per driver at the final load.JL sells the 12W1v3 as a single voice coil driver in a 2 ohm and a 4 ohm version; a matched pair should share an impedance. A pair of 2 ohm versions lands on 4 ohms in series or 1 ohm in parallel. A pair of 4 ohm versions lands on 2 ohms in parallel or 8 ohms in series. Many amplifiers are not stable at 1 ohm, so on the 2 ohm version series wiring to 4 ohms is the safe default. Confirm your amplifier's minimum stable impedance first.

Q: Why the wedge angle, and why rear-firing into the trunk?

The seat-side face carries a 20 degree rake that matches the lean of a factory rear seat back, so the cabinet sits flush against it and the cargo space in front stays usable. The baffle is the vertical trunk-lid-side face, so the drivers fire rearward into the trunk cavity.The trunk acts as an acoustic extension for the sealed box, and the cabin adds real output below 50 Hz, so in-vehicle response runs deeper than the anechoic 39.0 Hz on the 2 ohm version and 39.6 Hz on the 4 ohm version on this page.

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

Two drivers sharing one sealed volume load each other: each driver's compression stroke becomes the pressure the other works against, which blurs the alignment either would have alone. A bonded full-height 3/4 inch divider gives each driver its own 1.10 cubic feet and its own polyfill.It also means a failure in one driver does not unload the other, and the alignment on this page is the alignment in each chamber, not an average across a shared box.

Q: What is the expected low-frequency extension?

Anechoic F3 is 39.0 Hz on the 2 ohm version and 39.6 Hz on the 4 ohm version per chamber. Above Qtc 0.707 F3 sits below fc, so the response carries a small lift near resonance before it rolls off.Those figures exclude cabin gain. In a car the cabin's transfer function adds real output below 50 Hz, so in-vehicle response runs deeper than the numbers above.

Q: Do I need to add polyfill or damping?

No. Polyfill is already installed in both chambers as a light wall lining to control internal reflections, and the quantity is chosen so it does not change the acoustic volume.Do not add more. Packing a sealed box with fill makes it behave as though it were larger, which walks the alignment away from the 1.10 cubic feet per chamber this cabinet was built to.

Q: Is the driver included, and are the threaded inserts installed?

No driver. This is an enclosure only. You receive the cabinet finished in plush black carpet, one side-mounted pre-wired terminal cup to both positions, the polyfill lining already in place, and stainless machine screws.The threaded inserts are already pressed on JL's 11.7 inch bolt circle, so the 12W1v3 drops in and bolts down. The pair of JL Audio 12W1v3 is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 12 inch box.

SKU: PO 12D-S W W1V3 BB

QUICK SPECS

Best For: Dual JL Audio 12W1v3 Trunk-Fit Builds
Net Volume: 1.10 cu ft per chamber (2.36 cu ft Gross Total)
Driver Match: Pair of JL Audio 12W1v3 (2 ohm version and 4 ohm version), matched
Construction: Dual Chamber | Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | 1 Shared Terminal Cup | Threaded Inserts

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.

$ 399.99

Acrylic Insert Color

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

JL Audio 12W1v3 Dual Box: Sealed 12" Wedge Enclosure

More enclosures cut for JL Audio subwoofers: JL Audio Subwoofer Boxes

Enclosure Type Sealed

External Dimensions 32.00" W x 16" H x 15.46" D at base tapering to 9.64" D at top

Gross Volume 2.36 cu ft

Net Volume 2.20 cu ft

Shipping Weight 56 lbs

Front Panel Thickness 1.5"

INSTALLER'S TAKE

1.10 cubic feet per chamber: Qtc 0.948 on the 2 ohm version and Qtc 0.934 on the 4 ohm version, F3 39.0 Hz on the 2 ohm version and 39.6 Hz on the 4 ohm version.

The 5.41 inch motor clears the raked back with 3.73 to spare; the airspace sets the rest of the cabinet.

JL's 12W1v3 table holds together across both columns, and JL publishes the displacement, so nothing here is estimated.

Each chamber is JL's own 1.10 recommendation and lands on JL's printed figures to the tenth of a hertz. At Qtc 0.93 to 0.95 it runs well above maximally flat, with a clear lift near resonance, the way JL voices it.

Inserts are pressed on the 11.7 inch bolt circle. Sealed, so leave the polyfill as it is and run it at 300 watts or under per driver.

Product Details

Performance Optimized Wedge | Dual JL Audio 12W1v3

Dual 12" Sealed Wedge Enclosure | Rear-Firing Trunk-Load Design

1.10 ft3 Net per Chamber2.36 ft3 GrossQtc 0.93 to 0.95Two Separate Chambers32.00" x 16" x 9.64/15.46"Built in Tennessee

A Pair of JL Audio 12W1v3 in a Sealed Wedge

The 12W1v3 is JL's 12 inch W1v3, a single voice coil driver sold as a 2 ohm and a 4 ohm version, rated 300 watts RMS with 11.4 mm of one-way excursion, 5.41 inches of mounting depth on a 12.5 inch frame. Every Thiele-Small figure comes from JL's own owner's manual for the 12W1v3, both columns, and the table holds together: each column reproduces its own printed Qts, the two versions agree on Vas and resonance, and JL's own 1.10 cubic foot sealed box reproduces JL's printed Qtc of 0.950 and 0.934.

1.10 cubic feet net per chamber on JL's published figures: the 2 ohm version reads Qtc 0.948 with resonance at 48.3 Hz and half power at 39.0 Hz, and the 4 ohm version reads Qtc 0.934 with resonance at 48.8 Hz and half power at 39.6 Hz. One cabinet serves both versions. The volume is JL's own recommended sealed airspace for the 12W1v3, 1.10 cubic feet per driver, and on JL's published parameters this chamber reproduces JL's printed Qtc, fc and F3 for both versions. That is above maximally flat: punchy, with a clear lift near resonance and extra midbass, the alignment JL itself recommends.

Two Fully Separate Chambers

A bonded full-height 3/4 inch MDF divider splits the cabinet into two sealed chambers of 1.10 cubic feet net each, so every driver sees exactly the airspace printed on this page. Two drivers sharing one volume load each other; the divider removes that, and each chamber carries its own polyfill.

The cabinet is pinned at the 32 inch dual width cap, 16 inches tall, 9.64 inches deep at the top and 15.46 at the base, with the depth absorbing the airspace. One shared side-mounted terminal cup feeds both driver positions.

Trunk-Load Wedge Design Explained

The drivers mount on the vertical trunk-lid-side face and fire rearward into the trunk cavity.

Seat-Side Face Matches Seat Lean

Angled face matches the roughly 20 degree factory seat lean.

Trunk-Lid-Side Face Fires the Woofers

Vertical baffle, cones firing rearward into the trunk cavity.

Trunk Cavity Loading

The trunk acts as an acoustic extension for a smoother presentation.

Preserves Trunk Cargo Space

The wedge tucks against the seat back and the space in front stays usable.

Engineered for a pair of JL Audio 12W1v3

Anechoic half power lands at 39.0 Hz on the 2 ohm version and 39.6 Hz on the 4 ohm version, before any cabin gain. JL publishes the driver displacement, 0.052 cubic feet, and it is taken out of the net figure for each driver.

Alignment Numbers (Per Chamber)

Driver (per chamber)	System Qtc	fc	F3
12W1v3 2 ohm version	Qtc 0.948	48.3 Hz	39.0 Hz
12W1v3 4 ohm version	Qtc 0.934	48.8 Hz	39.6 Hz

Mounting Geometry

The baffle is cut to 11.0625 in, JL's published mounting hole, under the 12.5 in frame. The rear panel rakes 20 degrees, so the cavity deepens from 9.64 in at the top to 15.46 in at the base, and the 5.41 in motor clears it with 3.73 in to spare. Threaded inserts are pre-installed on JL's 11.7 inch bolt circle, with stainless machine screws, so the 12W1v3 bolts straight in.

What the Numbers Rest On

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" Front Baffle

Two bonded 3/4 in MDF sheets at the driver face, the outer layer machined as a flush recess.

JL's Published Parameters

2 ohm version: Fs 26.55 Hz, Qts 0.521, Qes 0.554, Qms 8.731, Vas 72.04 L, Re 2.21 ohm. 4 ohm version: Fs 26.21 Hz, Qts 0.502, Qes 0.535, Qms 8.2, Vas 76.63 L, Re 3.915 ohm. Cone area 525 cm2. Xmax 11.4 mm.

Wiring a pair of JL Audio 12W1v3 to Your Amplifier

JL sells the 12W1v3 as a single voice coil driver in a 2 ohm and a 4 ohm version; a matched pair should share an impedance. A pair of 2 ohm versions lands on 4 ohms in series or 1 ohm in parallel. A pair of 4 ohm versions lands on 2 ohms in parallel or 8 ohms in series. Many amplifiers are not stable at 1 ohm, so on the 2 ohm version series wiring to 4 ohms is the safe default. Confirm the final load against your amplifier's minimum stable impedance before powering the system.

Power handling is 300 watts RMS per driver, 600 across the pair. Aim for roughly 210 to 300 watts per driver at the impedance you wire.

Built in Tennessee, Backed by Audio Intensity

Cut and assembled in Tullahoma, Tennessee on our own CNC equipment. Finished in plush black carpet with the gloss black acrylic baffle insert, one shared pre-wired terminal cup, 12 gauge OFC to both driver positions. Polyfill wall lining installed. Threaded inserts pressed on the 11.7 inch bolt circle JL publishes, stainless machine screws in the box. 1 year limited warranty. Enclosure only, the drivers are purchased separately. Call or text 931-563-5151.

Dual JL Audio 12W1v3: Cut for This Driver

1.10 cubic feet net per chamber at Qtc 0.93 to 0.95, F3 39.0 Hz on the 2 ohm version and 39.6 Hz on the 4 ohm version, cut direct fit and built to order in Tennessee.

Specifications

Specification	Value
Series	Proline X Performance Optimized Wedge
Compatible Driver	JL Audio 12W1v3 (2 ohm version and 4 ohm version), quantity 2. Direct fit
Configuration	Dual 12 inch, two separate chambers, sealed wedge
Mounting Position	Trunk or cargo area, tall face against the rear seat back
Firing Direction	Rearward into the trunk. Not a down fire design, no feet included
External Width	32.00 in
External Height	16 in at the seat face
External Depth	15.46 in at the base, tapering to 9.64 in at the top
Internal Volume, Gross	2.36 cu ft total
Internal Volume, Net Acoustic	1.10 cu ft per chamber after the divider and the driver displacement
Driver Mounting Depth	5.41 in required; 3.73 in clearance above the motor against the raked rear panel
Alignment, 2 ohm version per chamber	Qtc 0.948, fc 48.3 Hz, F3 39.0 Hz anechoic
Alignment, 4 ohm version per chamber	Qtc 0.934, fc 48.8 Hz, F3 39.6 Hz anechoic
Woofer Opening	11.0625 in, two, JL's published mounting hole
Frame Outer Diameter	12.5 in, JL spec
Bolt Circle	11.7 in, JL spec; threaded inserts pre-installed
Driver Displacement	0.052 cu ft per driver, JL spec
2 ohm version Fs / Qts / Qes / Qms / Vas	26.55 Hz / 0.521 / 0.554 / 8.731 / 72.04 L
4 ohm version Fs / Qts / Qes / Qms / Vas	26.21 Hz / 0.502 / 0.535 / 8.2 / 76.63 L
Driver Sd	525 cm2, JL spec
Xmax	11.4 mm one way, JL spec
Driver Power Handling	300 W RMS per driver
Wiring Options	JL sells the 12W1v3 as a single voice coil driver in a 2 ohm and a 4 ohm version; a matched pair should share an impedance. A pair of 2 ohm versions lands on 4 ohms in series or 1 ohm in parallel. A pair of 4 ohm versions lands on 2 ohms in parallel or 8 ohms in series. Many amplifiers are not stable at 1 ohm, so on the 2 ohm version series wiring to 4 ohms is the safe default.
Parameter Source	JL Audio 12W1v3-2 / 12W1v3-4 owner's manual, both columns
Material	Langboard Elite MDF
Construction	CNC cut, V-groove and dado joinery
Panel Thickness	0.75 in
Front Baffle	1.5 in double baffle, outer layer machined as a flush recess
Internal Bracing	Full-height 3/4 in divider
Driver Mounting	Threaded inserts pre-installed on the 11.7 in bolt circle, stainless machine screws included
Terminal Cups	One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC to both driver positions
Acrylic Insert	Gloss black acrylic baffle insert standard; None variant minus $20
Damping	Light polyfill wall lining in both chambers, does not alter acoustic volume
Carpet	Plush black
Shipping Weight	56 lb
Warranty	1 Year Limited
Built In	Tullahoma, Tennessee

Performance Graphs

Net airspace

1.10

cu ft per chamber

System Qtc

0.93–0.95

sealed

Half power

39.0–39.6

Hz · F3

Xmax at

288

W RMS · no filter

With 25 Hz subsonic

309

W RMS · +7%

Amplifier

300

W RMS recommended

This enclosure holds 1.10 cu ft net per chamber. In it the JL Audio 12W1v3 runs a system Qtc of 0.93–0.95 with half power at 39.0–39.6 Hz, and the cone reaches its 11.4 mm travel limit at 288 W, below the driver’s 300 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 309 W — +21 W, or 7 percent more power for the same 11.4 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 47.9–49.0

12W1v3-2 · EBP 47.912W1v3-4 · EBP 49.0

EBP under 50 means a motor that wants a sealed load. The 12W1v3 sits at 47.9–49.0, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

1.10 cu ft against a 72.0 L Vas.

α = Vas ÷ Vb = 2.31 · Fc = Fs√(α+1) = 48–49 Hz · Qtc = 0.93–0.95

12W1v3-2 · Qtc 0.95, Fc 48 Hz, F3 39.0 Hz12W1v3-4 · Qtc 0.93, Fc 49 Hz, F3 39.6 Hz

The box lifts resonance from 26.2–26.6 Hz free-air to 48–49 Hz and half power lands at 39.0–39.6 Hz, anechoic, before any cabin gain. Parameters are JL Audio’s own owner’s manual for the 12W1v3, both columns: the 12W1v3-2 and 12W1v3-4 are single voice coil versions of one driver. JL publishes the driver displacement, 0.052 cu ft.

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

P_Xmax = 288–289 W unfiltered → 309 W with a 25 Hz subsonic

12W1v3-2 · 289 W, no filter12W1v3-4 · 288 W, no filter12W1v3-2 · 309 W with subsonic at 25 Hz, 24 dB/oct12W1v3-4 · 309 W with subsonic at 25 Hz, 24 dB/octXmax 11.4 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 11.4 mm. Unfiltered that is 288 W, reached first at 32 Hz. It sits under the 300 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 309 W before hitting the same 11.4 mm. That is 7 percent more amplifier for the price of one filter setting.

Param	Value	Unit	Note
Fs	26.55 / 26.21	Hz	free-air resonance
Qts	0.521 / 0.502		12W1v3-2 / 12W1v3-4
Vas	72.04 / 76.63	L	equivalent compliance
Sd	525.0	cm²	effective piston area
Xmax	11.4	mm	one-way, voice coil overhang method, as JL publish it
Pe	300	W	continuous RMS
SPL	85.7	dB	1 W / 1 m, derived from T/S

Driver parameters as published by JL Audio owner's manual. Curves computed against this enclosure’s actual net airspace.

Customer Installs

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.