Proline X PO 12DW-S W IDMAX sealed wedge, front baffle with gloss black insert and pre-wired leads, 41 by 16 inches.

Proline X

Performance Optimized Wedge Wide Sealed Dual 12" Enclosure | Image Dynamics IDMAX12 V.4

Q: Does this fit the IDMAX12 V.4 in both D2 and D4, and will any other 12 inch fit?

Yes, both coils: they share the 12.38 in frame, the 11.024 in cutout and the 8.07 in mounting depth, and the motor clears the cabinet with 0.75 in to spare. One cabinet serves both coils: the D2 reads Qtc 1.077 with half power at 33.9 Hz, and the D4 reads Qtc 1.299 at 32.0 Hz. Run two of the same coil so the chambers match.Any other 12, no. The airspace is worked out from the IDMAX12'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?

Image Dynamics rates the IDMAX12 V.4 at 500 watts RMS per driver, so target 350 to 500 watts RMS per driver at the final load, 700 to 1000 across the pair.The IDMAX12 V.4 ships as a D2 or a D4. A pair of D2 drivers lands on 2 ohms with each woofer's coils in series and the two woofers in parallel, or 8 ohms all in series; all four coils in parallel is 0.5 ohm, which almost nothing is stable into. A pair of D4 drivers lands on 4 ohms with each woofer's coils in series and the woofers in parallel, or 1 ohm with everything in parallel. Use 1 ohm only if your amplifier is rated 1 ohm stable. Run a matched pair, both D2 or both D4. Confirm your amplifier's minimum stable impedance first.

Q: Why the wide format, and why the raked back?

41 inches across lets two 12 inch drivers sit side by side while the cabinet stays 15.14 inches deep at the base, so it spans a cargo floor instead of eating into it. The back panel rakes 20 degrees to sit flush against the rear seat.The cargo area 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 33.9 Hz 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 1.32 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 33.9 Hz per chamber on the D2 at Qtc 1.077, and 32.0 Hz on the D4 at Qtc 1.299. Above Qtc 0.707 F3 sits below fc, so both carry a rise around their 44.4 Hz resonance before they roll off.Those figures exclude cabin gain. In a vehicle 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, and on a driver with this Qts the shift is far too small to change the alignment.

Q: Are the drivers included, and are the threaded inserts installed?

No drivers. This is an enclosure only. You receive the cabinet finished in plush black carpet with the gloss black acrylic baffle insert, 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: Image Dynamics publishes an 11.614 inch bolt circle for the IDMAX12, so we drill to it at the shop. The pair of IDMAX12 V.4 is purchased separately.

SKU: PO 12DW-S W IDMAX BB

QUICK SPECS

Best For: Dual Image Dynamics IDMAX12 V.4 Wide Cargo-Floor Builds
Net Volume: 1.32 cu ft per chamber (2.98 cu ft Gross Total)
Driver Match: Pair of Image Dynamics IDMAX12 V.4 (D2 or D4), matched
Construction: Dual Chamber | 41" Wide 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.

$ 469.99

Acrylic Insert Color

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Performance Optimized Wedge Wide Sealed Dual 12" Enclosure | Image Dynamics IDMAX12 V.4

More enclosures cut for Image Dynamics subwoofers: Image Dynamics Subwoofer Boxes

Enclosure Type Sealed

External Dimensions 41.00" W x 16" H x 15.14" D at base tapering to 9.32" D at top

Gross Volume 2.98 cu ft

Net Volume 2.64 cu ft

Shipping Weight 69 lbs

Front Panel Thickness 1.5"

INSTALLER'S TAKE

1.32 cubic feet per chamber on the 41 by 16 face: Qtc 1.077 on the D2, 1.299 on the D4, F3 33.9 and 32.0 Hz.

Read the alignment first. This is a high-Q box because the IDMAX is a high-Qts driver, 0.63 and 0.76, and no trunk-sized sealed box takes it near flat. It was solved to Image Dynamics' 1.25; the motor depth at 41 wide gives it a little more, which only helps.

At 41 wide it runs 15.14 deep at the base, so it spans a cargo floor instead of eating into it, with 0.75 inch over the motor.

Inserts pressed on the 11.614 bolt circle. Wire a D2 pair to 2 ohms or a D4 pair to 4, and run 350 to 500 watts per driver.

Product Details

Performance Optimized Wedge Wide | Dual Image Dynamics IDMAX12 V.4

Dual 12" Sealed Wide Wedge Enclosure | 41" Wide, 16" Tall

1.32 ft3 Net per Chamber2.98 ft3 GrossQtc 1.08 (D2)Two Separate Chambers41" x 16" x 9.32/15.14"Built in Tennessee

A Pair of Image Dynamics IDMAX12 V.4 in a Wide Sealed Wedge

This is the wide version of the IDMAX12 V.4 dual wedge: a fixed 41 inch by 16 inch face that spreads two IDMAX12 across the width of a cargo floor and keeps the cabinet shallow. The IDMAX12 V.4 is Image Dynamics' 12 inch with a 3 inch dual voice coil, 500 watts RMS, 19 mm of one-way travel on 547 square centimeters of cone, 8.07 inches of mounting depth and the bolt-on field-replaceable basket the IDMAX line is known for.

Image Dynamics' published Universal sealed airspace for the IDMAX12 V.4 is 1.25 cubic feet, and that is what this cabinet was solved to. At 41 inches wide the 8.07 inch motor sets the shallowest depth the cabinet can have, and at that depth each chamber holds 1.32 cubic feet net, slightly more. On this driver more air is the right direction: it brings Qtc down from 1.097 to 1.077 on the D2. One cabinet serves both coils: the D2 reads Qtc 1.077 with half power at 33.9 Hz, and the D4 reads Qtc 1.299 at 32.0 Hz.

Two Fully Separate Chambers

A bonded full-height 3/4 inch MDF divider splits the cabinet into two sealed chambers of 1.32 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 41.00 inches wide, 16 tall, 9.32 inches deep at the top and 15.14 at the base, against 17.43 at the base on the 32 inch version. One shared side-mounted terminal cup feeds both driver positions.

Wide Wedge Design Explained

The drivers mount on the vertical face and fire rearward; the back panel rakes 20 degrees to sit against the rear seat.

41 Inches Across

Wider than our standard 32 inch dual, so the cabinet can stay shallow and spread the pair across the floor.

16 Inches Tall

One height for the whole wide dual line, low enough to clear a cargo cover.

Raked Seat-Side Face

Matches the roughly 20 degree lean of a factory rear seat back.

Cargo Space Kept

15.14 inches at the base, so the floor in front stays usable.

Engineered for a pair of Image Dynamics IDMAX12 V.4

This is a high-Q sealed alignment and it is meant to be. The IDMAX12 V.4 publishes a Qts of 0.63 on the D2 and 0.76 on the D4, and a sealed system Q can never fall below the driver's own Qts however large the box. Reaching Qtc 0.707 on the D2 would take about 9.8 cubic feet per driver. What the higher Q buys is a rise around 44 Hz and half power at 32.0 to 33.9 Hz anechoic, before any cabin gain. Image Dynamics publishes the driver displacement, 0.1398 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
IDMAX12 V.4 D2	Qtc 1.077	44.4 Hz	33.9 Hz
IDMAX12 V.4 D4	Qtc 1.299	44.4 Hz	32.0 Hz

Mounting Geometry

Both baffle openings are CNC cut to 11.024 in, Image Dynamics' published cutout, under the 12.38 in frame. The rear panel rakes 20 degrees, so the cavity deepens from 9.32 in at the top to 15.14 in at the base, and the 8.07 in deep motor clears it with 0.75 in to spare. Image Dynamics publishes an 11.614 in bolt circle, so the threaded inserts are pressed at the shop on that circle and the drivers bolt straight down with the stainless machine screws supplied.

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.

Published Parameters

D2: Fs 26.0 Hz, Qts 0.63, Qes 0.73, Qms 4.72. D4: Fs 26.0 Hz, Qts 0.76, Qes 0.89, Qms 5.42. Vas 71.9 L on both, Sd 547 cm2, Xmax 19 mm. Image Dynamics publishes a different Vas for each coil; the figure used is the row whose moving mass reproduces its own free-air resonance.

Wiring a pair of Image Dynamics IDMAX12 V.4 to Your Amplifier

The IDMAX12 V.4 ships as a D2 or a D4. A pair of D2 drivers lands on 2 ohms with each woofer's coils in series and the two woofers in parallel, or 8 ohms all in series; all four coils in parallel is 0.5 ohm, which almost nothing is stable into. A pair of D4 drivers lands on 4 ohms with each woofer's coils in series and the woofers in parallel, or 1 ohm with everything in parallel. Use 1 ohm only if your amplifier is rated 1 ohm stable. Run a matched pair, both D2 or both D4. Confirm the final load against your amplifier's minimum stable impedance before powering the system.

Power handling is 500 watts RMS per driver, 1000 across the pair. Aim for roughly 350 to 500 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 in both chambers. Threaded inserts pressed on Image Dynamics' bolt circle, stainless machine screws in the box. 1 year limited warranty. Enclosure only, the drivers are purchased separately. Call or text 931-563-5151.

Dual Image Dynamics IDMAX12 V.4: 41 Inch Wide Sealed Wedge

1.32 cubic feet net per chamber at Qtc 1.077 on the D2, F3 33.9 Hz, cut direct fit and built to order in Tennessee.

Specifications

Specification	Value
Series	Proline X Performance Optimized Wedge Wide
Compatible Driver	Image Dynamics IDMAX12 V.4 D2 or D4, quantity 2. Direct fit
Configuration	Dual 12 inch, two separate chambers, sealed wide wedge
Mounting Position	Cargo floor or trunk, raked face against the rear seat back
Firing Direction	Rearward. Not a down fire design, no feet included
External Width	41.00 in
External Height	16 in at the seat face
External Depth	15.14 in at the base, tapering to 9.32 in at the top
Internal Volume, Gross	2.98 cu ft total
Internal Volume, Net Acoustic	1.32 cu ft per chamber, 2.64 total, after the divider and the 0.1398 cu ft driver displacement each
Driver Mounting Depth	8.071 in required; 0.75 in clearance above the motor against the raked rear panel
Alignment, D2 per chamber	Qtc 1.077, fc 44.4 Hz, F3 33.9 Hz anechoic
Alignment, D4 per chamber	Qtc 1.299, fc 44.4 Hz, F3 32.0 Hz anechoic
Image Dynamics Recommended Enclosure	1.25 cu ft sealed (Universal)
Woofer Opening	11.024 in, two
Frame Outer Diameter	12.382 in
Bolt Circle	11.614 in, Image Dynamics spec; threaded inserts pressed
Driver Displacement	0.1398 cu ft, Image Dynamics spec
D2 Fs / Qts / Qes / Qms	26.0 Hz / 0.63 / 0.73 / 4.72
D4 Fs / Qts / Qes / Qms	26.0 Hz / 0.76 / 0.89 / 5.42
Vas	71.9 L, both coils
Driver Sd	547 cm2
Xmax	19 mm one way
Driver Power Handling	500 W RMS per driver
Wiring Options	The IDMAX12 V.4 ships as a D2 or a D4. A pair of D2 drivers lands on 2 ohms with each woofer's coils in series and the two woofers in parallel, or 8 ohms all in series; all four coils in parallel is 0.5 ohm, which almost nothing is stable into. A pair of D4 drivers lands on 4 ohms with each woofer's coils in series and the woofers in parallel, or 1 ohm with everything in parallel. Use 1 ohm only if your amplifier is rated 1 ohm stable. Run a matched pair, both D2 or both D4.
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 pressed on Image Dynamics' 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	69 lb
Warranty	1 Year Limited
Built In	Tullahoma, Tennessee

Performance Graphs

Net airspace

1.32

cu ft per chamber

System Qtc

1.08–1.30

sealed

Half power

32.0–33.9

Hz · F3

Xmax at

672

W RMS · no filter

With 25 Hz subsonic

696

W RMS · +4%

Amplifier

500

W RMS recommended

This enclosure holds 1.32 cu ft net per chamber. In it the Image Dynamics IDMAX12 V.4 runs a system Qtc of 1.08–1.30 with half power at 32.0–33.9 Hz, and the cone reaches its 19.0 mm travel limit at 672 W, above the driver’s 500 W thermal rating, so heat stops you before travel does. A 25 Hz subsonic filter adds little here: 696 W against 672 W, 4 percent. The box already resonates at 44 Hz, so its own rolloff has removed most of what the filter would have stopped.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 29.2–35.6

D2 · EBP 35.6D4 · EBP 29.2

EBP under 50 means a motor that wants a sealed load. The IDMAX12 sits at 29.2–35.6, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

1.32 cu ft against a 71.9 L Vas.

α = Vas ÷ Vb = 1.92 · Fc = Fs√(α+1) = 44 Hz · Qtc = 1.08–1.30

D2 · Qtc 1.08, Fc 44 Hz, F3 33.9 HzD4 · Qtc 1.30, Fc 44 Hz, F3 32.0 Hz

The box lifts resonance from 26.0 Hz free-air to 44 Hz and half power lands at 32.0–33.9 Hz, anechoic, before any cabin gain. Image Dynamics publishes a different Vas for the D2 and the D4. A cone and suspension are shared across coil variants, so both cannot be right. The figure here is the row whose moving mass reproduces its own free-air resonance, applied to both coils. This wide cabinet targets Image Dynamics’ 1.25 cubic feet per chamber; at 41 inches wide the 8.07 inch motor sets the minimum depth, so each chamber holds 1.32.

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 19.0 mm, and in this alignment a subsonic filter barely moves it.

P_Xmax = 672–739 W unfiltered → 696–787 W with a 25 Hz subsonic

D2 · 739 W, no filterD4 · 672 W, no filterD2 · 787 W with subsonic at 25 Hz, 24 dB/octD4 · 696 W with subsonic at 25 Hz, 24 dB/octXmax 19.0 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 19.0 mm. Unfiltered that is 672 W, reached first at 37 Hz. It sits above the 500 W the driver can take thermally, so the voice coil gives up before the suspension does. The dashed traces are the same driver behind a subsonic filter at 25 Hz, 24 dB/oct, and they sit almost on top of the solid ones: 696 W against 672 W. At 44 Hz the filter sits well below resonance, where the sealed alignment has already rolled the cone off at 12 dB/oct, so there is little wasted travel left for it to recover. Set it anyway to keep road rumble out of the cone, but do not size the amplifier around it.

Param	Value	Unit	Note
Fs	26.00	Hz	free-air resonance
Qts	0.630 / 0.760		D2 / D4
Vas	71.90 / 71.90	L	equivalent compliance
Sd	547.0	cm²	effective piston area
Xmax	19	mm	one-way linear travel, bolt-on field-replaceable basket
Pe	500	W	continuous RMS
SPL	84.2	dB	1 W / 1 m, derived from T/S

Driver parameters as published by loudspeakerdatabase.com. 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.