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.

Performance Optimized · Datasheet

Performance Optimized Wedge Sealed 15" Enclosure | Kicker CompQ 15 Single 15" Sealed enclosure

Net volume
2.14 Cubic Feet
Max mounting depth
8.9375 Inches (Kicker Spec)
Cutout
13.875 Inches (Kicker Spec)
External dimensions
26.25 Inches W × 18 Inches H × 10.1 Inches / 16.65 Inches D
Front baffle
Vertical Trunk-Lid-Side Woofer Mounting Face
Buy at Audio Intensity
  • 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

Technical specifications

Enclosure TypeSealed | Wedge Geometry | Rear-Firing Trunk-Load
Driver-Specific FitmentKicker 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 Qtc0.75 (Musical Alignment | Based on Bench-Measured T/S)
Predicted F3~43 Hz
Predicted Fc~45 Hz
Driver Displacement0.25 Cubic Feet (Estimated - Kicker Does Not Publish)
Baffle ConfigurationVertical Trunk-Lid-Side Woofer Mounting Face
MaterialLangboard Elite 3/4" MDF
Front Baffle ConstructionDouble-Layer 1.5" MDF (Two 3/4" Sheets Bonded)
JoineryV-Groove and Dado (CNC-Cut)
ConstructionShopSabre CNC / Angled Seat-Side Compound Cuts / Perimeter Cross-Brace
External Width26.25 Inches
External Height18 Inches
External Depth (Top)10.1 Inches
External Depth (Bottom)16.65 Inches
Baffle Angle~20° From Vertical (Seat-Side Face)
Mounting Hole Diameter13.875 Inches (Kicker Spec)
Mounting Depth Required8.9375 Inches (Kicker Spec)
Mounting Hardware8/32 Threaded Inserts | Stainless Steel Machine Screws Included
Terminal CupProline X ABS/Carbon Fiber Composite | 10g OFC Pre-Wired
DampingPolyfill Pre-Installed
Recommended Power800-1000 Watts RMS (Kicker Rated: 1200W RMS Continuous)
Carpet FinishDark Gray Trunkliner (Standard) or Plush Black
Acrylic InsertBlack, Blue, Red, White, or None
Bundle OptionsEnclosure Only (Bring Your Own 51CWQ152 or 51CWQ154)
Warranty1-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA

Performance in this enclosure

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
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 D2 61.2 D4 56.9
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
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
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.

PXmax = 1900–2027 W unfiltered  →  2637–2773 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 8 16 24 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 23.7 mm 1900 W reaches Xmax here
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.
ParamValueUnitNote
Fs31.20Hzfree-air resonance
Qts0.485 / 0.538D2 / D4
Vas57.57 / 56.87Lequivalent compliance
Sd814.3cm²effective piston area
Xmax23.7mmone-way linear travel
Pe1200Wcontinuous RMS
SPL87.2dB1 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.

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.

Questions

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.

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.

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.

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.

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.

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.

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.

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.

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