A Proline PO 15-S W CompQ subwoofer enclosure shown on a dark promotional graphic with dimensions labeled 26.25 inches by 18 inches and feature text on the left.

A Proline Performance Optimized Series CompQ woofer enclosure, part PO 15-S W, shown as a 16.65 by 10.

Proline X

Performance Optimized Wedge Sealed 15" Enclosure | Kicker CompQ 15

Q: Will this enclosure fit both the 51CWQ152 and 51CWQ154?

Yes. The cutout, mounting depth, and terminal cup wiring are direct-fit for either impedance option. Choose based on your amplifier's ideal load.

Q: Why did you pick 2.14 cubic feet instead of Kicker's 1.5 or 6.0 cubic foot range?

2.14 cubic feet net puts the Kicker CompQ 15 at a Qtc of 0.75, which sits just above Butterworth for a slightly punchier musical alignment. Using bench-measured T/S parameters, Kicker's 1.5 cubic foot minimum produces a punchier Qtc around 0.82, and their 6.0 cubic foot maximum drops Qtc near 0.62 for extended deep-bass response. 0.75 is the sweet spot where the driver's motor control, cone response, and cabin loading all align.

Q: What amplifier power should I run to this enclosure?

The Kicker CompQ 15 is rated at 1200 watts RMS continuous. For a clean, headroom-rich musical system in this sealed alignment, target 800 to 1000 watts RMS at the woofer's impedance. It will happily accept the full 1200 watts but does not require it to sound its best.

Q: How does a wedge enclosure improve the sound in a trunk installation?

The driver mounts on the vertical face at the back of the box and fires rearward into the trunk cavity, using the trunk itself as an extension of the acoustic system. The angled face is on the opposite side, matching the roughly 20 degree lean of a factory rear seat back so the cabinet tucks in with no wasted gap. Firing into the trunk cavity takes advantage of the trunk's natural transfer function, loads the cabin efficiently, and reduces the standing-wave interaction that a flat-front box parallel to the rear seat can produce.

Q: Why is the front baffle double-layered on this enclosure?

All Performance Optimized Series enclosures use a double-layer 1.5 inch front baffle made from two bonded sheets of 3/4 inch Langboard Elite MDF. The Kicker CompQ 15 exerts significant mechanical load into its mounting flange at high output. A single 3/4 inch baffle can flex under that load and telegraph energy back into the cone. The double baffle eliminates that entirely and gives the driver a rigid, isolated mounting platform.

Q: What is the expected low-frequency extension of this enclosure?

At the Qtc 0.75 alignment, the predicted -3 dB point is approximately 43 Hz, with usable output well below that as cabin gain takes over in most vehicles. Effective in-car response typically extends down into the low 20 Hz range depending on the specific vehicle acoustics.

Q: Do I need to add any additional damping or polyfill to this enclosure?

No additional damping is required. The enclosure ships with polyfill pre-installed to the correct density for the volume and alignment. Adding more polyfill will effectively increase the perceived volume and shift the alignment. Removing it will do the opposite.

Q: Is the Kicker CompQ 15 subwoofer included with this enclosure?

No. This listing is for the enclosure only. Bring your own 51CWQ152 (DVC 2Ω) or 51CWQ154 (DVC 4Ω) driver.

SKU: PO 15-S W CompQ BB

QUICK SPECS

Best For: Kicker CompQ 15 Trunk-Fit Daily Driver Builds
Net Volume: 2.14 cu ft (2.39 cu ft Gross)
Driver Match: Kicker CompQ 15
Construction: Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | 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.

Performance Optimized Wedge Sealed 15" Enclosure | Kicker CompQ 15

Enclosure Type Sealed

External Dimensions 26.25" W x 18" H x 16.65" D at base tapering to 10.1" D at top

Net Volume 2.14cu ft

Tuning Frequency N/A (Sealed)

Cutout Diameter Direct Fit

Front Panel Thickness 1.5"

Max Mounting Depth Direct Fit

INSTALLER'S TAKE

The CompQ 15 gets underrated in the SQ world because it wears the round-cone version of an L7 badge, and everyone assumes it's a burp sub. It's not. Give it a proper musical sealed box and it plays with the same articulation and depth as any of the flagship SQ drivers in this size class, with more thermal headroom than most.

I built this one to 2.14 cubic feet net for a Qtc of 0.75, based on bench-measured T/S parameters. That's a hair above Butterworth, so you get a touch more midbass punch without giving up transient control. On this driver, in a wedge that loads the trunk this cleanly, 0.75 is the alignment that feels right on both kick drums and pipe organ pedals.

The double-baffle 1.5" front is not optional on this driver. The CompQ 15 puts real mechanical load into the mounting flange, and a single 3/4" layer will telegraph flex into the cone at high output. Two bonded 3/4" layers with the CNC-precision cutout kills that entirely.

If you're bringing your own amp, target 800-1000 watts RMS at the woofer's impedance for a clean, headroom-rich system. The CompQ 15 will happily eat the full 1200W but doesn't need it to sound its best.

Product Details

Performance Optimized Wedge | Kicker CompQ 15

15" Sealed Wedge Enclosure | Rear-Firing Trunk-Load Design for the Kicker CompQ 15

2.35 Cubic Feet 2.14 Cubic Feet Rear-Firing Wedge 26.25" × 18" × 10.1/16.65" V-Groove / Dado Built in Tennessee

The Kicker CompQ 15 in a Purpose-Built Sealed Wedge

The Kicker CompQ 15 is a proven mainstream performance driver with dual voice coils, 800 watts RMS rating, and a resilient stamped-steel frame. Ships in DVC 2 ohm (CWCS154) or DVC 4 ohm (CWCS152) configurations. Yellow injection-molded surround, ribbed spider, and back-fed lead technology for reliability under sustained output.

2.35 Cubic Feet gross internal volume produces 2.14 Cubic Feet after driver displacement. The wedge geometry mounts the woofer on the vertical trunk-lid-side face, firing rearward into the trunk cavity for optimum cabin loading.

Trunk-Load Wedge Design Explained

This wedge is not a front-firing enclosure. The woofer is mounted on the vertical face that sits at the back of the box, closest to the trunk lid, and fires rearward into the trunk cavity. The angled face is on the opposite side of the box, the side that faces the front of the vehicle, and tucks against the rear seat back.

Seat-Side Face Matches Seat Lean

Most factory rear seat backs lean roughly 20 degrees back from vertical. The angled face of this wedge matches that lean, tucking against the seat back with no wasted gap. The wedge fills the trunk shelf area behind the seat cleanly.

Trunk-Lid-Side Face Fires the Woofer

The vertical face on the opposite side of the wedge is where the driver mounts. The cone fires rearward toward the trunk lid, using the trunk cavity as an acoustic loading chamber. This is the classic SQ trunk-load install pattern.

Trunk Cavity Loading

Firing the woofer into the trunk cavity rather than directly into the cabin uses the trunk itself as an extension of the acoustic system. Low frequencies transmit into the passenger cabin through the rear deck, seat back, and cabin boundaries, a smoother, less localized presentation than direct-firing setups.

Preserves Trunk Cargo Space

The wedge tucks against the seat back where cargo can't be stored anyway. The bottom face sits flat and stable on the trunk floor. Cargo space in front of the wedge (toward the trunk lid) stays usable for daily driving.

Engineered for the Kicker CompQ 15

This cabinet is engineered specifically for the Kicker CompQ 15 to deliver a musical, controlled sealed alignment at Qtc 0.75 based on published T/S parameters. F3 lands at approximately 43 Hz with strong cabin gain typical of trunk installations extending that meaningfully lower in-vehicle.

Alignment Numbers

System Qtc: 0.75 · F3: 43 Hz · Fc: 48 Hz

Mounting Geometry

The vertical trunk-lid-side baffle is CNC-cut to Direct Fit. Mounting depth required is Direct Fit, with the wedge geometry providing ample interior clearance for the driver's motor and cooling requirements. 8/32 threaded inserts are pressed into the baffle backside for secure driver retention.

Performance Series Construction, Driver-Specific Tuning

Langboard Elite MDF

Premium 3/4" MDF panels milled to documented spec: denser and more dimensionally stable than commodity MDF. Less panel resonance, tighter joints, and a longer service life under daily use.

V-Groove and Dado Joinery

CNC-cut V-grooves at every panel intersection let the wedge cabinet fold into its angled shape with maximum glue surface. Dado joints lock the vertical woofer baffle and the angled seat-side panel into the side walls. No fasteners visible from outside.

Double-Layer 1.5" Front Baffle

Two bonded 3/4" MDF sheets at the driver mounting face. The double baffle eliminates flex under high mechanical load and gives the driver a rigid, isolated mounting platform.

Pre-Wired Terminal Cup

Proline X ABS/carbon-fiber composite terminal cup with 12 gauge OFC pre-wired to the driver position. 3D-printed in-house on Bambu Lab H2S 3D printers. 8/32 threaded inserts installed for secure driver retention.

Customize Your Build

Carpet Finish

Standard finish is charcoal gray trunk liner. Optional plush black carpet finish adds $10 for a slightly more premium look.

Acrylic Insert Color

Choose from Black, Blue, Red, White, or opt out entirely (-$40).

Box-Only or Loaded

This listing is box-only. Bring your own driver.

Wiring the Kicker CompQ 15 to Your Amplifier

The Kicker CompQ 15 ships in DVC 2 ohm (CWCS154) or DVC 4 ohm (CWCS152). Choose the impedance that matches your amplifier's stable load rating for the desired power output. The terminal cup provides the final connection to your amp.

Built in Tennessee, Backed by Audio Intensity

Manufactured in Tullahoma, Tennessee on our ShopSabre CNC equipment. Every enclosure is CNC-cut, hand-assembled, glued and clamped, wrapped in carpet, and quality-checked by the same small team. 1-year limited warranty on the enclosure. Questions on fitment or amplifier matching, call 931-563-5151.

Kicker CompQ 15: Precision-Tuned in a Trunk-Load Wedge

2.14 Cubic Feet net, engineered for the Kicker CompQ 15 in a wedge geometry that fires the driver rearward into the trunk cavity. Precise driver-specific engineering.

Specifications

Enclosure Type	Sealed \| Wedge Geometry \| Rear-Firing Trunk-Load
Driver-Specific Fitment	Kicker CompQ 15 - 51CWQ152 (DVC 2Ω) or 51CWQ154 (DVC 4Ω)
Internal Volume (Gross)	2.39 Cubic Feet
Internal Volume (Net After Displacement)	2.14 Cubic Feet
Target System Qtc	0.75 (Musical Alignment \| Based on Bench-Measured T/S)
Predicted F3	~43 Hz
Predicted Fc	~45 Hz
Driver Displacement	0.25 Cubic Feet (Estimated - Kicker Does Not Publish)
Baffle Configuration	Vertical Trunk-Lid-Side Woofer Mounting Face
Material	Langboard Elite 3/4" MDF
Front Baffle Construction	Double-Layer 1.5" MDF (Two 3/4" Sheets Bonded)
Joinery	V-Groove and Dado (CNC-Cut)
Construction	ShopSabre CNC / Angled Seat-Side Compound Cuts / Perimeter Cross-Brace
External Width	26.25 Inches
External Height	18 Inches
External Depth (Top)	10.1 Inches
External Depth (Bottom)	16.65 Inches
Baffle Angle	~20° From Vertical (Seat-Side Face)
Mounting Hole Diameter	13.875 Inches (Kicker Spec)
Mounting Depth Required	8.9375 Inches (Kicker Spec)
Mounting Hardware	8/32 Threaded Inserts \| Stainless Steel Machine Screws Included
Terminal Cup	Proline X ABS/Carbon Fiber Composite \| 10g OFC Pre-Wired
Damping	Polyfill Pre-Installed
Recommended Power	800-1000 Watts RMS (Kicker Rated: 1200W RMS Continuous)
Carpet Finish	Dark Gray Trunkliner (Standard) or Plush Black (+$10)
Acrylic Insert	Black, Blue, Red, White, or None (-$40)
Bundle Options	Enclosure Only (Bring Your Own 51CWQ152 or 51CWQ154)
Warranty	1-Year Limited (Enclosure)
Manufactured	Tullahoma, Tennessee, USA

Performance Graphs

Net airspace

2.14

cu ft per chamber

System Qtc

0.68–0.75

sealed

Half power

42.7–45.5

Hz · F3

Xmax at

1900

W RMS · no filter

With 25 Hz subsonic

2637

W RMS · +39%

Amplifier

1200

W RMS recommended

This enclosure holds 2.14 cu ft net per chamber. In it the Kicker CompQ 15 (51CWQ152) runs a system Qtc of 0.68–0.75 with half power at 42.7–45.5 Hz, and the cone reaches its 23.7 mm travel limit at 1900 W, above the driver’s 1200 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 2637 W — +737 W, or 39 percent more power for the same 23.7 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 56.9–61.2

D2 · EBP 61.2D4 · EBP 56.9

At 56.9–61.2 the CompQ 15 (51CWQ152) sits in the transition band, not the sealed band. That is not a mismatch: a transition motor works in either alignment, and sealed buys a smaller box and a gentler roll-off at the cost of some low-end output. Stage 02 shows what this airspace actually does with it.

02What the box does to it

2.14 cu ft against a 57.6 L Vas.

α = Vas ÷ Vb = 0.95 · Fc = Fs√(α+1) = 44–45 Hz · Qtc = 0.68–0.75

D2 · Qtc 0.68, Fc 44 Hz, F3 45.5 HzD4 · Qtc 0.75, Fc 45 Hz, F3 42.7 Hz

The box lifts resonance from 31.2 Hz free-air to 44–45 Hz and half power lands at 42.7–45.5 Hz, anechoic, before any cabin gain. This enclosure ships without a driver, so both coil variants the maker offers are plotted. They do not load the same box the same way.

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

P_Xmax = 1900–2027 W unfiltered → 2637–2773 W with a 25 Hz subsonic

D2 · 1900 W, no filterD4 · 2027 W, no filterD2 · 2773 W with subsonic at 25 Hz, 24 dB/octD4 · 2637 W with subsonic at 25 Hz, 24 dB/octXmax 23.7 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 23.7 mm. Unfiltered that is 1900 W, reached first at 20 Hz. It sits above the 1200 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: stopping the cone wasting travel below the passband lets it take 2637 W before hitting the same 23.7 mm. That is 39 percent more amplifier for the price of one filter setting.

Param	Value	Unit	Note
Fs	31.20	Hz	free-air resonance
Qts	0.485 / 0.538		D2 / D4
Vas	57.57 / 56.87	L	equivalent compliance
Sd	814.3	cm²	effective piston area
Xmax	23.7	mm	one-way linear travel
Pe	1200	W	continuous RMS
SPL	87.2	dB	1 W / 1 m, derived from T/S

Driver parameters as published by Kicker published Klippel T/S sheet. Curves computed against this enclosure’s actual net airspace.

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.