Proline X
Proline X PO 15D-S W | Dual 15" Sealed Wedge Enclosure | Built for ResoNix GUS-15
SKU: PO 15D-S W GUS-GRY
- Driver: ResoNix GUS-15 x2, direct fit only
- Net Acoustic: 1.35 cu ft per driver, 2.70 total
- Alignment: Qtc 0.707, ResoNix target
- Chambers: Dual, full divider
- Position: Trunk mount, tall face against rear seat
- Firing: Rearward. No down fire option
- Footprint: 36 in W x 16.5 in D at the base
- Terminal Cups: Two, one per chamber
- Weight: 60 lb
Financing available — choose Shop Pay Installments at checkout.
Proline X PO 15D-S W | Dual 15" Sealed Wedge Enclosure | Built for ResoNix GUS-15
Two GUS-15s. Trunk Mounted, the Way a Wedge Is Meant to Sit.
A dual chamber sealed wedge cut for the ResoNix GUS-15 and nothing else. It sits in the trunk or cargo area with the tall face against the back of the rear seat and the drivers firing rearward, so the box uses the length of the trunk instead of standing in the middle of it.
This Is Not a Down Fire Enclosure
The wedge only works in one orientation: tall face flat against the rear seat back, taper running out toward the trunk lid, drivers firing rearward. There are no feet, no baffle clearance gap, and no down fire option on this cabinet.
If you need an enclosure that can run down fire, the Proline X Micro Series Dual 15 Sealed Enclosure Built for ResoNix GUS-15 is the one for that. Square stack fab cabinet, feet included, runs either orientation. Same driver, same airspace target, different build and a different place in the vehicle.
Built for One Driver, at One Volume
Performance Optimized enclosures are cut for a specific subwoofer rather than a size class. This one is built around the ResoNix GUS-15, and Audio Intensity is the exclusive enclosure builder for the GUS platform.
ResoNix publishes 1.35 cubic feet as the volume that produces a maximally flat sealed alignment for the GUS-15. Each chamber here is built at 1.425 cubic feet gross. Subtract the driver's 0.072 cubic feet of displacement and each driver sees 1.353 cubic feet, which lands on the published target rather than near it. Total gross volume across both chambers is 2.85 cubic feet, 2.70 net acoustic.
The woofer opening is cut direct fit to the GUS-15 at 355mm. There is no universal 15 inch cutout here and no attempt at one, which is the entire point of the Optimized line. A standard 15 will not work in this cabinet, both because of the opening and because the depth is built around this driver.
Why a Wedge
The wedge is the oldest trunk enclosure shape in car audio for a reason. It is built around what a trunk actually is, rather than dropping a rectangle into one.
It Uses the Trunk Lengthwise
Tall face against the rear seat, tapering down as it runs out toward the lid. The cabinet claims the deep space at the base of the trunk and gives the height back where the lid closes, so you keep usable trunk instead of losing the middle of it.
The Trunk Is Part of the System
Firing rearward means the output loads into the trunk volume and reaches the cabin through the rear seat and deck. That path is what gives a trunk mounted subwoofer its weight, and it is why moving a box a few inches changes what you hear.
Harder to Point At
Because the drivers do not radiate straight into the cabin, the low end arrives through the structure rather than as a beam from behind your head. On a well built system that makes keeping the stage forward considerably easier.
Two Chambers, Two Cups
Each driver gets its own sealed chamber and its own terminal cup. No internal cross chamber wiring, so you can run a monoblock per driver or bridge externally.
Dual Chamber, Not Common Chamber
Each GUS-15 loads into its own sealed 1.425 cubic foot chamber, isolated by a full divider. This matters at this power level. With separate chambers, one driver's cone motion does not modulate the air load the other driver sees, so the two stay acoustically independent under hard excursion.
It also means the two chambers can be driven separately. Each Proline X terminal cup is pre wired with 12 gauge OFC to its own driver, so the common configurations are a dedicated monoblock per driver, or a single high output amplifier bridged externally across the two terminals. The GUS-15 is rated at 1500 watts RMS each in its suggested enclosure, so this cabinet is a 3000 watt system when both chambers are driven properly. The dual amplifier path gives the cleanest channel separation and the most consistent damping at that power level.
How It Is Built
Cabinet
Cut on our ShopSabre CNC from Langboard Elite MDF and assembled with dado and V groove joinery over 0.75 inch panels, with a double baffle at 1.5 inches and a full chamber divider. This is a different construction method from the stack fab Micro Series, and the wedge geometry is the reason. The angled panel meets are cut as V joints so the faces close on a machined bevel rather than a filled seam.
Mounting Pattern
The GUS-15 is in the Proline X CAD library, drawn from the manufacturer's own CAD file. The cutout and the nutsert locations are machined in the same operation from the same origin on the router, so the holes cannot drift relative to each other. 8/32 threaded inserts are installed at both driver positions with stainless machine screws supplied, matched to the driver's 375mm bolt circle.
Wiring and Damping
Two Proline X ABS and carbon fiber composite terminal cups, side mounted, one per chamber, each pre wired with 12 gauge OFC. Polyfill is installed as a light wall lining to control internal reflections without altering the acoustic volume, because ResoNix calculated the target at 1.35 cubic feet and adding fill density would shift the alignment off it.
Finish
Dark gray trunk liner standard, plush black available. The lasered acrylic badge mounts on the woofer face.
Fitment
External dimensions are 36 inches wide by 17.5 inches tall, with the depth running 16.5 inches at the base and tapering to 10 inches at the top. Installed, the 17.5 inch face stands against the rear seat back and the cabinet slopes away toward the trunk lid.
Measure the floor, then the lid. The 16.5 inch base depth and the 36 inch width are what has to clear on the trunk floor. The taper is there so the lid closes over the shallow end, but check your own lid line, since trunk openings vary far more than trunk floors do.
Front clearance. ResoNix specifies a 33mm minimum clearance in front of each GUS-15. At 25.89mm of Klippel verified one way excursion that figure is the operational envelope of the suspension, not optional headroom. Nothing should sit inside it, including cargo you expect to load behind the box. Verify both driver positions independently.
Enclosure Performance
These figures are calculated from ResoNix's own published Klippel measured parameters for the GUS-15 D4 coil: Fs 17.11 Hz, Qts 0.34, Vas 117.47 litres. Nothing here is estimated.
| Volume Per Driver | Qtc | fc | F3 | Character |
|---|---|---|---|---|
| 0.80 cu ft, ResoNix minimum | 0.846 | 42.6 Hz | 36.7 Hz | Tighter, more upper bass emphasis |
| 1.35 cu ft, this enclosure | 0.686 | 34.5 Hz | 35.6 Hz | Maximally flat. The target. |
| 2.00 cu ft, ResoNix maximum | 0.596 | 30.0 Hz | 36.6 Hz | Overdamped, softer, more headroom |
The thing the curves actually show. Look at the F3 column, not the Qtc column. Across the entire usable range, from ResoNix's minimum 0.8 up to their maximum 2.0 cubic feet, F3 moves less than two hertz. Enclosure volume on this driver changes the shape of the response, not how deep it plays. Going bigger does not buy extension. It buys damping and headroom, and it costs you upper bass. That is unusual, and it is a direct result of an Fs of 17 Hz paired with a Qts of 0.34.
Why we built at 1.35. The small box gains upper bass emphasis and the large box gains control, and neither gains bottom end. 1.35 cubic feet sits at the maximally flat point between them, which is why it is ResoNix's own published recommendation. They designed the driver, and this is the alignment they built it around.
What flat means in a trunk. These figures are anechoic. Installed in a vehicle, cabin transfer function lifts the bottom octave regardless of alignment, and a rear firing trunk mount adds the loading of the trunk itself on top of that. In practice the in-car response will be considerably warmer than the curve above.
Run your own numbers with the Sealed Box Calculator.
Full dimensions, cutout, mounting depth, and hardware details are listed under the Enclosures tab.
Cut for the GUS-15. Built in Tennessee.
Enclosure only. The ResoNix GUS-15 drivers are purchased separately from ResoNix Sound Solutions. Every Performance Optimized Wedge is built to order in Tullahoma, Tennessee on our own CNC equipment. Questions on fitment or amplifier matching, call or text 707-999-3071.
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Wedge |
| Compatible Driver | ResoNix GUS-15, quantity 2. Direct fit, no other driver |
| Configuration | Dual 15 inch, dual chamber 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 | 36 in |
| External Height | 17.5 in at the seat face |
| External Depth | 16.5 in at the base, tapering to 10 in at the top |
| Internal Volume, Gross | 2.85 cu ft total, 1.425 cu ft per chamber |
| Internal Volume, Net Acoustic | 2.70 cu ft total, 1.35 cu ft per driver after displacement |
| Target Alignment | Qtc 0.707, ResoNix published target |
| Driver Displacement | 0.072 cu ft each |
| Woofer Opening | 356.17mm direct fit, both positions |
| Min Front Clearance | 33mm, both drivers |
| Material | Langboard Elite MDF |
| Construction | CNC cut, dado and V groove joinery |
| Panel Thickness | 0.75 in |
| Front Baffle | 1.5 in, double baffle |
| Chamber Divider | Full divider, no shared airspace |
| Driver Mounting | 8/32 threaded inserts, stainless machine screws included, both positions |
| Terminal Cups | Two Proline X ABS and carbon fiber composite, side mounted, one per chamber, independently pre wired |
| Internal Wiring | 12 gauge OFC |
| Damping | Light polyfill wall lining, does not alter acoustic volume |
| Carpet | Dark gray trunk liner standard, plush black available |
| Badge | Woofer face mounted, lasered acrylic |
| Weight | 60 lb |
| Warranty | 1 Year Limited |
| Built In | Tullahoma, Tennessee |
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.
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 |
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.
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.
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.
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.
Handcrafted in USA
Hand-assembled at our facility in Tullahoma, TN. Every enclosure is inspected before it ships.
Tuned to the Build
Internal volume and port geometry are calculated to spec and CNC-cut to exact dimensions. The box performs the same way every time.
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