Professional Series · Datasheet

Professional Series Ported Dual 15" Enclosure Image Dynamics IDMAX15 V4 · Dual 15" Ported enclosure

Net volume
5.06 Cubic Feet
Tuning
34.0 Hz
Max mounting depth
10.433 Inches (Image Dynamics Spec)
Cutout
14.764 Inches (Image Dynamics Spec)
External dimensions
44.00 Inches W × 18.00 Inches H × 17.50 Inches D
Front baffle
Three 3/4" MDF layers, 2.25" total | Woofer Flush-Mounted In The Outer Layer
Buy at Audio IntensityFactory-direct, ships from Tullahoma
  • Alignment: 5.06 cu ft net vented at 34.0 Hz. F3 31.8 Hz anechoic, 5.78 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, 2.25" three-layer 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, straight, port and excursion gated at 1440 W
  • Cabinet: 44.00" W x 18.00" H x 17.50" D, 71 lb, threaded inserts pressed into the baffle on the published 15.551 inch bolt circle

Spec of record

Technical specifications

SeriesProline X Professional
Driver-Specific FitmentImage Dynamics IDMAX15 V4 D2 (Dual 2 Ohm)
Enclosure TypePorted | Front-Firing Standard Box
External Width44.00 Inches
External Height18.00 Inches
External Depth17.50 Inches
Internal Volume (Gross)5.88 Cubic Feet
Internal Volume (Net After Displacement)5.06 Cubic Feet
Port TypeVertical Slot Beside The Woofer | Front Exit | Straight, No Bend
Port Geometry2.25 x 16.50 Inches, 37.1 Square Inches, 11.11 Inches Of Path
Port Area37.1 Square Inches
Port Tuning (Fb)34.0 Hz
Port Mouth1/2 In Roundover On All Four Edges, 56.9 Square Inches At The Face
Port Air Velocity25.0 m/s In The Channel, 16.3 m/s At The Mouth, At 1440 W (17.0 m/s Chuff Threshold)
Design Power Basis1440 W RMS (1.2 x The Driver Rating) For Port Velocity And Excursion
Predicted F331.8 Hz (Anechoic)
Passband Ripple5.78 dB (Anechoic)
Subsonic Filter27 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs30.00 Hz
Driver Qts0.952
Driver Qes / Qms1.203 / 4.810
Driver Vas77.540 Liters / 2.738 Cubic Feet
Driver Sd935.0 Square Centimeters
Driver Mms386.00 g
Driver BL15.10
Driver Re3.6 Ohm
Driver Xmax22mm (One-Way)
Driver Displacement0.26 Cubic Feet (Published by Image Dynamics)
Driver Sensitivity87.2 dB
Driver Power Handling600 Watts RMS
Driver Overall Diameter16.016 Inches (Image Dynamics Spec)
Mounting Depth Required10.433 Inches (Image Dynamics Spec)
Cutout Diameter14.764 Inches (Image Dynamics Spec)
Flush Mount Recess17.000 Inches In The Outer Layer
MaterialLangboard Elite 3/4" MDF
ConstructionShopSabre CNC / Windowed Brace Front To Back Beside The Woofer
JoineryDado Joinery (CNC-Cut), Flat Panels
Front Baffle ConstructionThree 3/4" MDF layers, 2.25" total | Woofer Flush-Mounted In The Outer Layer
Baffle Layers3
AcrylicGlossy Black Image Dynamics Logo Insert, Outer Layer, Standard
Mounting HardwareThreaded Inserts On The Published 15.551 In Bolt Circle | Stainless Machine Screws Included
Voice Coil ConfigurationDual 2 Ohm
Terminal CupProline X ABS/Carbon Fiber Composite | Back Panel, Terminal-Cup Side | 12g OFC Pre-Wired
DampingNone - Ships Dry. Polyfill Detunes A Ported Enclosure
Recommended Power420-600 Watts RMS (Image Dynamics Rated: 600W RMS)
Carpet FinishPlush Black
Weight71 lb
ShippingUPS Ground Parcel, Included In The 48 States
Bundle OptionsEnclosure Only (Bring Your Own Image Dynamics IDMAX15 V4)
Warranty2-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA

Modelled response

Performance in this enclosure

Net airspace
5.06
cu ft
Tuning
34.0
Hz · Fb
Half power
31.8
Hz · F3, anechoic
Xmax at
13471
W RMS · 27 Hz subsonic
With NO filter
1797
W RMS · unfiltered
Port
16.3
m/s at the mouth · 1440 W

01Is this driver right for a ported box?

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

EBP = Fs ÷ Qes = 24.9
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 EBP 24.9
Image Dynamics IDMAX15 V4 D2 · EBP 24.9
Under 50 the raw number leans sealed. The Image Dynamics IDMAX15 V4 D2 reads 24.9, so this is a ported build against the grain of its own EBP: it works because the alignment is tuned for in-car response rather than for an anechoic curve, and because the cabinet holds port area and volume the driver can actually use.

02What the box does to it

5.06 cu ft net against a 155.1 L Vas, vented at 34.0 Hz.

Fb = 34.0 Hz  ·  F3 = 31.8 Hz  ·  passband ripple 5.78 dB
20 30 50 70 100 150 200 +16 +12 +8 +4 0 −4 −8 −12 −16 −20 −24 −28 FREQUENCY · Hz LEVEL · dB −3 dB Fb 34.0
Image Dynamics IDMAX15 V4 D2 · Fb 34.0 Hz, F3 31.8 Hz
Anechoic, before any cabin gain, with the 27 Hz subsonic filter already applied. The vent takes over below 34 Hz and the cone stops doing the work there, which is what holds travel down at the bottom of the passband.

03Perceived Ported vs Sealed

This cabinet, 5.06 cu ft net vented at 34.0 Hz, against Image Dynamics's recommended sealed box, 2.00 cu ft (2.00 gross, 1.74 net after the driver) per driver, 3.48 cu ft for the pair.

Ported Fb 34.0 Hz  ·  the 3.48 cu ft sealed box runs Qtc 1.53, Fc 48 Hz
20 30 50 70 100 150 200 +16 +12 +8 +4 0 −4 −8 −12 −16 −20 −24 −28 FREQUENCY · Hz LEVEL · dB +4.0 dB at 23 Hz
Ported · this cabinet, 5.06 cu ft, Fb 34.0 HzImage Dynamics's recommended sealed, 1.74 cu ft net x2, 3.48 cu ft, Qtc 1.53
Shaded blue is where the ported alignment is louder for the same power, orange where the sealed one is. The sealed curve is Image Dynamics's recommended sealed box, 2.00 cu ft (2.00 gross, 1.74 net after the driver) per driver, 3.48 cu ft for the pair, not this cabinet with the port blocked: two different boxes, because that is the choice a buyer actually has. Across 25 to 60 Hz the vent is worth 3.7 dB at its widest and 2.8 dB on average. This is the anechoic picture, which is not what you hear in a car.

04Real World Ported vs Sealed

The same two boxes with cabin gain applied, 45 Hz corner, 18 dB ceiling.

Flatness across 25–60 Hz: ported 2.8 dB spread, the 3.48 cu ft sealed box 3.5 dB
20 30 50 70 100 150 200 +16 +12 +8 +4 0 −4 −8 −12 −16 −20 −24 −28 FREQUENCY · Hz LEVEL · dB +4.0 dB at 23 Hz
Ported, in-car · 2.8 dB spreadImage Dynamics's recommended sealed, 1.74 cu ft net x2, 3.48 cu ft, in-car · 3.5 dB spread
Cabin gain lifts both boxes by the same amount, so the gap between them does not change: what changes is the shape each one ends up with. A car pressurises below roughly 45 Hz, which fills in the sealed box's shallower rolloff and over-drives it where the ported box is already flat. Across 25 to 60 Hz, the band kick and bass fundamentals occupy, this alignment holds 2.8 dB of spread against 3.5 dB for Image Dynamics's recommended sealed box, 2.00 cu ft (2.00 gross, 1.74 net after the driver) per driver, 3.48 cu ft for the pair. Flatter is the whole point of tuning this high. The two alignments converge at the bottom of the band rather than crossing cleanly, so there is no meaningful subsonic advantage either way here. Cabin gain here is a house assumption, not a measurement of your vehicle.

05The watts that reach Xmax (in this enclosure)

Travel scales with the square root of power, so there is one wattage that puts both cones exactly on Image Dynamics's published 22.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off. Every power figure in this section is for the pair, split evenly.

PXmax = 13471 W with a 27 Hz subsonic  ·  1797 W with none  →  the filter is worth 7.5×
20 30 50 70 100 150 200 0 8 16 24 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 22.0 mm 13471 W reaches Xmax here
13471 W · subsonic at 27 Hz, 24 dB/oct1797 W · no subsonic filterXmax 22.0 mm one-way, published
Each trace touches the limit and no further, because each is drawn at the exact power that puts the cone on 22.0 mm. With a 27 Hz subsonic that takes 13471 W, reached first at 50 Hz. Take the filter away and the same cabinet reaches 22.0 mm on 1797 W — the filter is worth 7.5× the safe power. A vent unloads the cone below tuning, so there is nothing holding it once the box stops loading: on a sealed build a subsonic filter is an improvement, here it is required equipment. The unfiltered trace is still rising where this chart stops at 20 Hz, so treat 1797 W as a bound rather than a floor. Every wattage on this page is a MECHANICAL limit, not an electrical one. It is the power at which the cone runs out of linear travel in this cabinet, and nothing more. What the voice coil can dissipate as heat is a separate ceiling set by the driver, not by the box — Image Dynamics rate this one at 1200 W RMS, and that is the number that binds first here: heat stops you before travel does, so treat 1200 W as the ceiling and the travel figures above as headroom. Final wired impedance, amplifier output and how long you hold the level are all electrical questions this graph does not answer.

From the shop floor

Installer's take

I built this one for a pair of IDMAX15 V4 in a single shared chamber, which is how a dual ported box should be built: one volume, one port, both drivers loading the same air.

It gets the full Professional treatment, a 2.25 inch three-layer baffle with both woofers flush mounted in the outer layer, and the port on the left of the face.

Wiring is where a dual bites you. These are its coils, so you can land on a load your amplifier is rated for. Check what your amplifier is rated for before you wire it, not after.

It ships dry. Do not add polyfill to a ported box. Set your subsonic filter at 27 Hz.

Before you order

Questions

Why is this enclosure tuned to 34.0 Hz?

Both drivers share one chamber and one port rather than sitting in separate boxes, so the pair works against the whole volume and the port is sized for the pair rather than doubled. The port carries 37.1 square inches of area at 34.0 Hz, and the design power for the velocity and excursion checks is 1440 W for the pair. Passband ripple holds at 5.78 dB across the tuning, with F3 at 31.8 Hz. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz, and this tuning is where that sum comes out flattest across 25 to 60 Hz.

Why is this a Professional build and not a Performance Optimized box?

Every driver is run through the Performance Optimized wedge and down-fire before this chassis; the Professional box is where a driver lands when that smaller envelope, 30 inches wide and 18 inches deep with a triangular side port, cannot give it what it needs at its rated power. The IDMAX15 V4 did not clear the ripple 5.51 dB over 4.5 gate there: the nearest wedge that fits is 24.5 by 11.25 by 17.98 inches with a 23.0 square inch port, and no tuning, width or depth inside that envelope passes. The slot on this box reaches 37.1 square inches. An under-ported box does not fail quietly. Air speed at the mouth rises with power; past the chuff line the flow turns turbulent and the port is audible on every note. The turbulence also chokes the port, so the box behaves as if it were tuned higher than it is, loses output near tuning, and lets the cone travel further below tuning than the design allows. This chassis is a full-size front-firing box on a 2.25 inch baffle built from three 3/4 inch layers with the woofer flush-mounted in the outer layer, an Image Dynamics logo acrylic, and a port and excursion budget checked at 1440 W. It carries a 2 year warranty against 1.

Threaded inserts or a kit?

Threaded inserts pressed into the baffle on the published 15.551 inch bolt circle, stainless machine screws included. The inserts are in the baffle when it arrives; the machine screws are in the terminal cup bag.

Do I need a subsonic filter?

Yes, at 27 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 33 percent of its usable travel at 1440 W.

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, 5.06 cubic feet vented at 34.0 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.

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 8.86 inches straight back to a 2.48 inch throat gap. The channel runs at 25.0 metres per second at 1440 W, 52 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 16.3 metres per second against the 17 metres per second threshold where a slot starts to chuff.

What does the price cover, and how does it ship?

71 lb, 44.00" W x 18.00" H x 17.50" D external. It ships as a UPS parcel; the price includes shipping in the 48 states. Every Professional cabinet is priced the same way, by its size: this one is 8.02 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 71 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.

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 5.06 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.

Same series, same size

Other Professional Series models