A product specification graphic for a Proline Performance Optimized Series PO 12-S-W Solo X woofer enclosure. The image features a dimensioned diagram of the woofer's interior showing 17.A black rectangular speaker enclosure or woofer mounting panel shown on a dark promotional graphic with dimensions labeled 11.75 inches, 15.

Performance Optimized · Datasheet

Performance Optimized Wedge Enclosure | Fits Kicker Solo X 12" Subwoofer Single 12" Sealed enclosure

Net volume
1.13 Cubic Feet
Max mounting depth
10-1/8 Inches, Cleared With Margin
Cutout
11-1/16 Inches (Kicker Spec)
External dimensions
16.75 Inches W × 15.25 Inches H × 11.75 Inches / 17.25 Inches D
Front baffle
Double-Layer 1.5" MDF Plus Trim Layer
Buy at Audio Intensity
  • Alignment: 1.13 cu ft net sealed wedge, tightly damped. Dual 1-ohm 49L7X121 runs Qtc 0.61, Fc 50 Hz, F3 59.8 Hz; dual 2-ohm 49L7X122 runs Qtc 0.64, Fc 52 Hz, F3 58.8 Hz
  • Geometry: 20° front-firing wedge, vertical rear panel. 16.75 in W x 15.25 in H x 11.75 in top / 17.25 in bottom depth
  • Driver: Kicker Solo X L7X 12 (either coil version). Baffle CNC-cut to 11-1/16 in per Kicker spec, 10-1/8 in mounting depth cleared with margin
  • Wiring: One side-mounted terminal cup, 12 gauge OFC pre-wired. Kicker recommends 1000-2000 watts RMS; set final impedance at the driver's coils
  • Cabinet: 3/4 in Langboard Elite MDF, 1.5 in double-layer baffle plus trim, dado-locked brace behind the woofer, plush black carpet with black acrylic insert

Technical specifications

SeriesProline X Performance Optimized Wedge
Compatible DriverKicker Solo X L7X 12 (49L7X121 Dual 1-Ohm / 49L7X122 Dual 2-Ohm)
Enclosure TypeSealed | Single Driver | Front-Firing Wedge
Wedge Angle20 Degrees, Vertical Rear Panel
External Width16.75 Inches
External Height15.25 Inches
External Depth (Top)11.75 Inches
External Depth (Bottom)17.25 Inches
Internal Gross Volume1.33 Cubic Feet
Net Volume (After Driver Displacement)1.13 Cubic Feet
System Qtc (Dual 1-Ohm)0.61 Tightly Damped
System Qtc (Dual 2-Ohm)0.64 Tightly Damped
Predicted Fc50 Hz (D1) / 52 Hz (D2)
Predicted F3 (Anechoic)59.8 Hz (D1) / 58.8 Hz (D2)
Driver Fs (D1 / D2)40.3 Hz / 41.6 Hz (Kicker Factory)
Driver Qts (D1 / D2)0.487 / 0.506 (Kicker Factory)
Driver Vas (D1 / D2)18.05 L / 18.36 L (Kicker Factory)
Woofer Cutout11-1/16 Inches (Kicker Spec)
Mounting Depth Required10-1/8 Inches, Cleared With Margin
Recommended Power1000-2000 Watts RMS (Kicker Recommendation)
MaterialLangboard Elite 3/4" MDF
ConstructionShopSabre CNC | V-Groove and Dado Joinery
Panel Thickness3/4 Inch
Front BaffleDouble-Layer 1.5" MDF Plus Trim Layer
Internal Bracing3/4" Dado-Locked Brace Behind Woofer
Driver Mounting8/32 Threaded Inserts | Stainless Machine Screws Included
Terminal CupOne Proline X ABS/Carbon Fiber Composite | Side Mounted
Internal Wiring12 Gauge OFC, Pre-Wired
FinishPlush Black Carpet | Black Acrylic Insert
Bundle OptionsEnclosure Only (Bring Your Own Solo X 12)
Warranty1-Year Limited (Enclosure)
Built InTullahoma, Tennessee, USA

Performance in this enclosure

Net airspace
1.13
cu ft per chamber
System Qtc
0.61–0.63
sealed
Half power
58.8–59.8
Hz · F3
Xmax at
4802
W RMS · no filter
With 25 Hz subsonic
6874
W RMS · +43%
Amplifier
1000–2000
W RMS recommended
This enclosure holds 1.13 cu ft net per chamber. In it the Kicker SoloX L7X 12 (49L7X121) runs a system Qtc of 0.61–0.63 with half power at 58.8–59.8 Hz, and the cone reaches its 31.25 mm travel limit at 4802 W, above the driver’s 2000 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 6874 W — +2072 W, or 43 percent more power for the same 31.25 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 76.5–78.2
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 D1 78.2 D2 76.5
D1 · EBP 78.2D2 · EBP 76.5
At 76.5–78.2 the SoloX L7X 12 (49L7X121) 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

1.13 cu ft against a 18.0 L Vas.

α = Vas ÷ Vb = 0.56  ·  Fc = Fs√(α+1) = 50–52 Hz  ·  Qtc = 0.61–0.63
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
D1 · Qtc 0.61, Fc 50 Hz, F3 59.8 HzD2 · Qtc 0.63, Fc 52 Hz, F3 58.8 Hz
The box lifts resonance from 40.3–41.6 Hz free-air to 50–52 Hz and half power lands at 58.8–59.8 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 31.25 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 4802–5009 W unfiltered  →  6874–6949 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 8 16 24 32 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 31.25 mm 4802 W reaches Xmax here
D1 · 4802 W, no filterD2 · 5009 W, no filterD1 · 6949 W with subsonic at 25 Hz, 24 dB/octD2 · 6874 W with subsonic at 25 Hz, 24 dB/octXmax 31.25 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 31.25 mm. Unfiltered that is 4802 W, reached first at 20 Hz. It sits above the 2000 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 6874 W before hitting the same 31.25 mm. That is 43 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs40.30 / 41.60Hzfree-air resonance
Qts0.487 / 0.506D1 / D2
Vas18.05 / 18.36Lequivalent compliance
Sd585.6cm²effective piston area
Xmax31.25mmone-way linear travel
Pe2000Wcontinuous RMS
SPL85.5dB1 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 12 is the do-everything box of this line. In 1.13 net cubic feet both coil versions land at Qtc 0.61 to 0.64, the tightly damped pocket just below Butterworth where you keep essentially flat response but pick up extra cone control and power handling headroom. It splits the difference between the maximally damped 10 and the textbook-flat 15, and for most truck builds it is the sweet spot.

Twelve-inch Solo X cone area with SoloX excursion is serious displacement, and the sealed loading is what lets you use it. Kicker says 1000-2000 watts RMS; in this alignment the air spring loads the cone progressively harder below Fc, so the driver stays composed at full tilt where a ported box near tuning would let it wander. An honest 1500 watts here embarrasses most ported dailys on control.

Coils are an amplifier decision. The alignments are three hundredths of a Q apart, inaudible in any vehicle. Dual 1-ohm wires to 0.5 or 2 ohms, dual 2-ohm to 1 or 4; pick the one that lands on your amp's rated load and move on.

Fit is friendlier than a 12 has any right to be: 16.75 wide, 15.25 tall, 17.25 deep at the floor tapering to 11.75 up top. The height is the number to check; measure from the floor to the lowest point of the seat back or headrest interference with the seat where you actually keep it. Cabin gain takes the high-50s anechoic F3 down into the range people mean when they say a 12 hits.

Questions

Will my Kicker Solo X 12 fit this enclosure?

Yes. The baffle is CNC-cut to Kicker's published 11-1/16 inch cutout for the Solo X L7X 12, and the cabinet clears the required 10-1/8 inch mounting depth with margin at every point of the stroke, including breathing room for the vented motor. Both the dual 1-ohm 49L7X121 and dual 2-ohm 49L7X122 fit identically.

What does tightly damped mean for how this box sounds?

Tightly damped means the system Q sits a step below the 0.707 Butterworth point, here 0.61 to 0.64. Response stays essentially flat with zero peaking, and the extra damping margin shows up as cone control: transients stop cleanly, and the driver takes big power gracefully because the box is always loading it. You trade a small amount of theoretical extension versus a higher-Q tune and get precision back. In a truck cab, where cabin gain restores the bottom octave anyway, that is a trade you want.

Which coil version should I buy, dual 1-ohm or dual 2-ohm?

Choose by amplifier, not by the box. In this airspace the dual 1-ohm runs Qtc 0.61 and the dual 2-ohm 0.64 with F3s within a hertz of each other; no cab will reveal the difference. Buy the coil configuration that wires to the impedance your amplifier makes its rated power into: dual 1-ohm gives you a 0.5 or 2 ohm final, dual 2-ohm gives you 1 or 4 ohms.

How much power should I run to the Solo X 12 in this box?

Kicker recommends 1000-2000 watts RMS for the Solo X 12 and this sealed alignment supports the full range. The air spring keeps excursion controlled as level rises, so the top of the range stays usable with properly set gains. Clean power beats big power; an honest 1200-1500 watts delivers everything most daily systems ask of a 12.

Why sealed instead of ported for the Solo X 12?

A ported box would play louder at and above its tuning frequency, no argument. What it costs is size, since a properly ported Solo X 12 needs far more volume than fits behind a seat, and control, since below tuning the cone unloads. This sealed wedge keeps the enclosure behind-seat sized, keeps the cone loaded at every frequency, and delivers flat, accurate response that cabin gain extends downward. Chasing maximum SPL means a ported build on the cargo floor; chasing tight, musical bass in a cab means this box.

Will this wedge fit behind the seat of my truck?

You need 16.75 inches of width, 15.25 inches of height, and 17.25 inches of depth at the floor; the top needs only 11.75 inches because the baffle rakes back 20 degrees to follow the seat lean. The rear panel is fully vertical and sits flat against the cab wall. Height is the dimension that catches people on a 12, so check your clearance to the seat back with the seat in its normal position before ordering.

Is the subwoofer included with this enclosure?

No, this listing is the enclosure only. It is built specifically for the Kicker Solo X L7X 12 in either coil configuration, and you install your own driver using the pressed 8/32 threaded inserts and included stainless mounting hardware. If you want help pairing a Solo X 12 or an amplifier with it, call us at 931-563-5151.

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