Proline X

Professional Series Ported 15" Enclosure | Image Dynamics IDMAX15 V4

Q: What makes this Professional rather than Performance Optimized?

The box. A Performance Optimized cabinet is cut to fit a trunk shape on a 1.5 inch double baffle; this one is a full-size front-firing box on a 2.25 inch triple baffle with the woofer flush-mounted in the outer layer, an Image Dynamics logo acrylic, and a port and excursion budget checked at 900 W rather than the rating. It carries a 2 year warranty against 1. The IDMAX15 V4 needs the depth and the face this box gives it.

Q: Do I need a subsonic filter?

Yes, at 21 Hz, 24 dB per octave. Below tuning a vented box stops loading the cone and excursion runs away toward DC. With the filter in place this cabinet puts the Image Dynamics IDMAX15 V4 at 46 percent of its usable travel at 900 W.

Q: Would a sealed box be better for me?

The two alignments converge at the bottom of the band on this driver rather than crossing cleanly, so there is no meaningful subsonic advantage either way. Above 25 Hz the vent is the louder of the two for the same power. The Performance Graphs tab plots this cabinet, 2.72 cubic feet vented at 26.5 Hz, against Image Dynamics's recommended sealed box, 2.00 cu ft (2.00 gross, 1.74 net after the driver), so you can judge it yourself.

Q: How does the front port work?

It is a vertical slot beside the woofer, the full height of the cavity, 2.25 inches wide and 37.1 square inches. It runs 9.50 inches to the back wall and turns once along it for 25.14 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 13.3 metres per second at 900 W, 47 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 8.7 metres per second against the 17 metres per second threshold where a slot starts to chuff.

Q: How heavy is it and how does it ship?

88 lb, 36.00" W x 18.00" H x 15.50" D external. It ships as a UPS parcel; the price includes shipping in the 48 states. Do not add polyfill; it ships dry on purpose.

Q: Is the IDMAX15 V4 included?

No. This is an enclosure only, cut for the Image Dynamics IDMAX15 V4 specifically: the 14.764 inch cutout, the 10.433 inch mounting depth allowance and the 2.72 cubic foot alignment all come from Image Dynamics's published parameters. It fits both coil versions; the alignment published here is the D2. Bring your own driver.

SKU: Pro 15-P IDMAX

QUICK SPECS

Alignment: 2.72 cu ft net vented at 26.5 Hz. F3 29.6 Hz anechoic, 4.46 dB passband ripple
Driver: Image Dynamics IDMAX15 V4 D2, 600 W RMS, 22.0 mm Xmax, 30.00 Hz Fs
Build: Front-firing standard box, triple 2.25" baffle with the woofer flush-mounted in the outer layer, Image Dynamics logo acrylic, dado joinery, 37.1 sq in front slot port beside the woofer with one bend along the back wall, port and excursion gated at 900 W
Cabinet: 36.00" W x 18.00" H x 15.50" D, 88 lb, threaded inserts pressed into the baffle on the published 15.551 inch bolt circle

Shipping Included No freight charges at checkout on US orders. International orders are quoted live carrier rates at checkout.

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.

$ 609.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Complete Your System

Image Dynamics Image Dynamics IDMAX15 V4 15 inch Subwoofer $ 679.99

Image Dynamics Image Dynamics SQ1200.1D 1200W Mono Block Amplifier $ 504.99

Professional Series Ported 15" Enclosure | Image Dynamics IDMAX15 V4

$ 609.99

Enclosure Type Ported

External Dimensions 36.00" W x 18.00" H x 15.50" D

Net Volume 2.72cu ft

Tuning Frequency 26.5 Hz

Port Area 37.1 Square Inches

Cutout Diameter Direct Fit

Front Panel Thickness 2.25"

INSTALLER'S TAKE

I built this box because the IDMAX15 kept being asked for and nothing in the trunk lines would hold it. The motor is deep and the frame is wide, so it gets the full-size standard box: three layers of baffle, the flange flush in the outer one, the port beside it on the front face.

The port is wide on purpose. At one and a half times the rated 600 watts the air in the channel is still well under the point where a slot starts to chuff, so you can run a real amplifier on this without hearing the port. Set your subsonic at 21 Hz and leave it there.

Wire the D2 series for 4 ohms unless the amplifier is rated for 1 ohm. Six hundred watts is the coil's thermal limit and it binds long before the cone runs out of travel in this box, so heat is what you manage, not excursion.

It ships dry. Do not add polyfill to a ported box.

Product Details

Proline X Professional 15" Ported

The fifteen that needs a full-size box, vented near 27 Hz on a triple baffle

2.72 cu ft net Tuned 26.5 Hz F3 29.6 Hz Triple 2.25" baffle Cut for the IDMAX15 V4 Built in Tennessee

2.72cu ft net

26.5Hz tuning

29.6Hz F3 anechoic

37.1sq in port area

Why this driver is vented at 26.5 Hz

The IDMAX15 V4 carries 10.433 inches of mounting depth and a 16 inch frame, and neither trunk chassis will take it: the ported Down Fire caps at 8.50 inches of height and the wedge has no fifteen-inch ported height it fits. The Professional box stands 18 inches tall, flush-mounts the flange in a 2.25 inch triple baffle, and gives the motor the depth it needs. It gets 2.72 cubic feet net, vented at 26.5 Hz, in a 36 inch wide cabinet beside the front port.

Image Dynamics publish a Qts of 0.95 at 30 Hz for the D2 coil, and that figure is genuine: their Qes and Qms reproduce it and the motor constants agree. A driver that damped wants a large box and a low vent, and their own manual says so, recommending 3.0 cubic feet gross at 27 Hz for the Universal alignment. This cabinet lands on it: 4.12 gross, 2.72 net after the driver, port and braces, vented at 26.5 Hz, which is where the in-car curve comes out flattest. Passband ripple sits at 4.46 dB, and that number is the driver's Q rather than the box; tuning higher or lower makes it worse, not better.

What makes it Professional

Triple baffle, flush mount

Three layers of 3/4 inch Langboard Elite make a 2.25 inch front. The outer layer is routed to the flange, so the woofer sits flush with the face; the two layers behind it carry the mounting hardware and the load.

Image Dynamics logo acrylic

A glossy black acrylic insert with the Image Dynamics mark sits in the outer layer beside the woofer. It is standard on every Professional cabinet.

Mounting

Threaded inserts pressed into the baffle on the published 15.551 inch bolt circle, stainless machine screws included.

Port gated at 900 W

The 37.1 square inch slot beside the woofer is sized so the channel runs 13.3 metres per second and the mouth 8.7 metres per second at one and a half times the driver's rating, under the 17 metres per second where a slot starts to chuff. The channel runs 9.50 inches along its wall and turns once along the back wall for another 25.14 inches, which is why a 26.5 Hz tuning fits a 15.50 inch deep box.

The cabinet

36.00" W x 18.00" H x 15.50" D external. Two windowed braces run front to back either side of the woofer, clearing the cutout by two and a half inches. The box ships dry: polyfill detunes a ported alignment. Inside the 36 by 18 Professional envelope for a single 15, with the depth the motor needs. It ships as a parcel.

The two coils publish different Vas figures, 77.5 litres for the D2 and 84.8 for the D4, which a shared cone and suspension cannot produce. The D2 column is the published alignment here and the cabinet fits either coil. Image Dynamics recommend a sealed box for this driver; the ported Professional gives up nothing in control above 30 Hz and adds the output the motor is rated for, provided the subsonic filter is set.

The numbers to respect

Set a 21 Hz subsonic filter, 24 dB per octave. Below tuning the vent stops loading the cone; with the filter in place the cone reaches 10.0 mm of its 22.0 mm at 900 W.

Enclosure Specifications

Series	Proline X Professional
Driver-Specific Fitment	Image Dynamics IDMAX15 V4 D2 (Dual 2 Ohm)
Enclosure Type	Ported \| Front-Firing Standard Box
External Width	36.00 Inches
External Height	18.00 Inches
External Depth	15.50 Inches
Internal Volume (Gross)	4.12 Cubic Feet
Internal Volume (Net After Displacement)	2.72 Cubic Feet
Port Type	Vertical Slot Beside The Woofer \| Front Exit \| One 90 Degree Bend Along The Back Wall
Port Geometry	2.25 x 16.50 Inches, 37.1 Square Inches, 40.64 Inches Of Path
Port Area	37.1 Square Inches
Port Tuning (Fb)	26.5 Hz
Port Mouth	1/2 In Roundover On All Four Edges, 56.9 Square Inches At The Face
Port Air Velocity	13.3 m/s In The Channel, 8.7 m/s At The Mouth, At 900 W (17.0 m/s Chuff Threshold)
Design Power Basis	900 W RMS (1.5 x The Driver Rating) For Port Velocity And Excursion
Predicted F3	29.6 Hz (Anechoic)
Passband Ripple	4.46 dB (Anechoic)
Subsonic Filter	21 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs	30.00 Hz
Driver Qts	0.952
Driver Qes / Qms	1.203 / 4.810
Driver Vas	77.540 Liters / 2.738 Cubic Feet
Driver Sd	935.0 Square Centimeters
Driver Mms	386.00 g
Driver BL	15.10
Driver Re	3.6 Ohm
Driver Xmax	22mm (One-Way)
Driver Displacement	0.26 Cubic Feet (Published by Image Dynamics)
Driver Sensitivity	87.2 dB
Driver Power Handling	600 Watts RMS
Driver Overall Diameter	16.016 Inches (Image Dynamics Spec)
Mounting Depth Required	10.433 Inches (Image Dynamics Spec)
Cutout Diameter	14.764 Inches (Image Dynamics Spec)
Flush Mount Recess	17.000 Inches In The Outer Layer
Material	Langboard Elite 3/4" MDF
Construction	ShopSabre CNC / Two Windowed Braces Front To Back Either Side Of The Woofer
Joinery	Dado Joinery (CNC-Cut), Flat Panels
Front Baffle Construction	Triple-Layer 2.25" MDF \| Woofer Flush-Mounted In The Outer Layer
Baffle Layers	3
Acrylic	Glossy Black Image Dynamics Logo Insert, Outer Layer, Standard
Mounting Hardware	Threaded Inserts On The Published 15.551 In Bolt Circle \| Stainless Machine Screws Included
Voice Coil Configuration	Dual 2 Ohm
Terminal Cup	Proline X ABS/Carbon Fiber Composite \| Back Panel, Terminal-Cup Side \| 12g OFC Pre-Wired
Damping	None - Ships Dry. Polyfill Detunes A Ported Enclosure
Recommended Power	420-600 Watts RMS (Image Dynamics Rated: 600W RMS)
Carpet Finish	Plush Black
Weight	88 lb
Shipping	UPS Ground Parcel, Included In The 48 States
Bundle Options	Enclosure Only (Bring Your Own Image Dynamics IDMAX15 V4)
Warranty	2-Year Limited (Enclosure)
Manufactured	Tullahoma, Tennessee, USA

Woofer Details

Materials

Material

Built From a Spec Sheet, Not a Sales Sheet

Every Proline X Professional 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 Professional 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.

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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.