Proline X Performance Wedge P12-WS III Sealed Enclosure for 12" Subwoofers
Precision-Built Sealed Enclosure for Deep, Accurate Bass – Compatible with Most 12-Inch Subwoofers
-
Free Shipping
Free Standard Shipping to the Lower 48 States!
Proline-X Performance P12-WS III Wedge Sealed Enclosure
Third Generation Space-Saving Design for 12" Subwoofers
Introducing the P12-WS III: Evolution Meets Innovation
Proline-X proudly presents the third generation of our wedge-style sealed enclosure—the P12-WS III. Building on years of customer feedback and real-world installation experience, this latest iteration represents our most refined approach to the eternal challenge facing trunk-mounted subwoofer systems: how to maximize bass performance while minimizing intrusion into valuable cargo space.
The P12-WS III answers this challenge with intelligent slant-back (wedge) geometry that hugs the rear seat contour naturally, reducing effective depth penetration into the trunk while maintaining the optimal 1.25 ft³ sealed airspace that 12" subwoofers demand for accurate, musical bass response. This isn't just a cosmetic modification—it's a fundamental reimagining of enclosure geometry optimized for the realities of modern vehicle architecture.
The Wedge Advantage: Form Follows Function
Traditional rectangular enclosures waste space through their uniform depth. When positioned against a rear seat, the bottom edge sits flush while the top extends unnecessarily far into trunk space—creating a gap between enclosure and seat that serves no acoustic purpose while consuming precious cargo volume.
The P12-WS III's wedge profile eliminates this wasted space by tapering from 14.5" depth at the bottom to 9.25" depth at the top. This slant-back geometry allows the enclosure to nestle against angled rear seatbacks, maintaining the full 1.25 ft³ internal volume while appearing significantly less intrusive when viewed from above. The result is a win-win: identical acoustic performance with dramatically improved space efficiency.
Traditional P12-S
(Rectangular)
- Dimensions: 19.5"W × 14.5"H × 11.5"D
- Volume: 1.25 ft³
- Profile: Uniform 11.5" depth throughout
- Gap Behind: 2-4" air gap between top edge and rear seat
- Trunk Intrusion: Full 11.5" depth consumes cargo space
- Best For: Vertical installations, hatchbacks, SUVs
NEW P12-WS III
(Wedge/Slant-Back)
- Dimensions: 16"W × 14.5"H × (9.25" top / 14.5" bottom)
- Volume: 1.25 ft³ (identical airspace)
- Profile: Tapered wedge follows seat contour
- Gap Behind: Minimal—hugs rear seat naturally
- Trunk Intrusion: Reduced effective depth (~3-5" space savings)
- Best For: Sedans, coupes, angled rear seats
Third Generation Refinements
The "III" designation signifies this is the third evolution of our wedge design. Each generation has incorporated customer feedback, installation insights from professional shops, and our own testing refinements:
- Generation I: Initial wedge concept proved space-saving geometry, but width and angle required further optimization
- Generation II: Refined taper angle and adjusted width for improved universal fitment across sedan platforms
- Generation III (Current): Optimized 16" width for better side-to-side clearance in compact trunks, refined 9.25"/14.5" taper ratio for maximum space savings while maintaining structural integrity
The P12-WS III represents the culmination of this iterative design process—the most refined, universally compatible, space-efficient sealed 12" enclosure we've ever produced.
Technical Specifications
| Specification | Value |
|---|---|
| Model | P12-WS III (Performance Wedge Sealed, Generation 3) |
| Series | Performance Series |
| Enclosure Type | Sealed (Acoustic Suspension) |
| Configuration | Single 12" subwoofer |
| Profile Design | Wedge / Slant-Back (tapered depth) |
| Generation | Third Generation (Gen III) |
| Net Internal Volume | 1.25 ft³ (35.4 liters) |
| Woofer Cutout Diameter | 11.13" (282.7mm) |
| Mounting Depth Available | ~8.5" (accounts for internal bracing, terminal cup) |
| External Width | 16.0" (406mm) |
| External Height | 14.5" (368mm) |
| External Depth (Top) | 9.25" (235mm) - shallow end |
| External Depth (Bottom) | 14.5" (368mm) - deep end |
| Average Depth | ~11.9" (effective trunk intrusion) |
| Wedge Angle | ~20° taper (optimized for rear seat contours) |
| Material | 3/4" (19mm) premium MDF from Oregon |
| Construction Method | Proprietary dado-cut interlocking joints |
| CNC Equipment | ShopSabre industrial routers (±0.005" tolerance) |
| Assembly Adhesive | Titebond II Premium Wood Glue (pre-assembled) |
| Internal Bracing | Heavy strategic bracing for panel rigidity |
| Terminal Cup | High-power custom cup, stainless steel hardware |
| Speaker Wire | Pre-installed 12-gauge OFC (oxygen-free copper) |
| Finish Options | Dark Gray Trunk Liner OR Plush Black Carpet |
| Corner Design | Rounded corners (easier installation, aesthetic) |
| Airtight Seal | Yes (pre-assembly + glue ensures no leaks) |
| Manufacturing Location | Handcrafted in Vacaville, California, USA |
| Warranty | 1-year against internal leaking or joint failure |
Wedge Geometry: Engineering Space Efficiency
The Physics of Slant-Back Design
At first glance, the wedge profile might seem purely cosmetic—a styling exercise. In reality, it's a sophisticated solution to a geometry problem that has plagued trunk-mounted subwoofer installations for decades.
The Problem: Modern sedan rear seats typically recline at 20-30° from vertical. When you place a rectangular enclosure against this angled surface, you create a triangular void between the enclosure's flat back and the seat's angled surface. This wasted space can measure 2-4 inches at the top of the enclosure—space that could be reclaimed for cargo or simply make the installation appear less intrusive.
The Solution: The P12-WS III's back panel angles at approximately 20°, closely matching typical rear seat recline angles. This allows the enclosure to nestle against the seat naturally, eliminating the wasted triangular void while maintaining full internal airspace through increased width and height dimensions.
Dimensional Analysis: Volume Preservation
Maintaining the optimal 1.25 ft³ sealed volume while transitioning to wedge geometry requires careful dimensional balancing. Here's how the P12-WS III achieves it:
Volume Calculation Verification
Rectangular P12-S: 19.5"W × 14.5"H × 11.5"D = 3253 cubic inches ≈ 1.88 ft³ external
Internal volume (accounting for 3/4" MDF walls, bracing, woofer displacement): 1.25 ft³
Wedge P12-WS III: Trapezoidal prism calculation
16"W × 14.5"H × average depth 11.875" [(9.25+14.5)/2] = 2755 cubic inches ≈ 1.59 ft³ external
Internal volume (accounting for MDF, bracing, woofer displacement): 1.25 ft³
Identical internal airspace achieved through optimized wedge geometry—no acoustic compromise.
Real-World Space Savings
The practical benefit of wedge geometry becomes clear when measuring actual trunk intrusion:
- Rectangular P12-S: Full 11.5" depth from rear seat to front edge of enclosure
- Wedge P12-WS III: Only 9.25" depth at top, 14.5" depth at bottom (where trunks are naturally deeper)
- Effective Space Savings: 3-5 inches of reclaimed cargo space at the critical upper trunk area where items are most frequently loaded/unloaded
In compact sedan trunks where every inch matters, this 3-5" space savings can mean the difference between fitting golf clubs, luggage, or groceries comfortably versus struggling with trunk organization.
Structural Integrity in Angled Designs
Wedge enclosures present unique structural challenges compared to rectangular boxes. Angled panels create non-perpendicular joints that require sophisticated joinery to maintain airtight seals and prevent panel flexure under bass pressure.
The P12-WS III addresses these challenges through:
Dado-Cut Angled Joints
CNC-cut dado grooves are precisely angled to match the 20° wedge taper, creating mechanical interlocking joints that resist shear forces better than simple butt joints. The dado depth (3/8") provides substantial glue surface area for superior bond strength.
Strategic Bracing Placement
Internal braces span the widest dimension (bottom to angled back panel), triangulating loads and preventing the angled panel from flexing inward under bass pressure. Brace placement is calculated via finite element analysis to optimize stiffness while minimizing airspace displacement.
Increased Panel Thickness
3/4" MDF throughout provides inherent panel stiffness that resists flexure even in angled configurations. Thinner materials would require more bracing, consuming internal volume and adding weight.
Corner Reinforcement
Rounded corners aren't just aesthetic—they distribute stress more evenly than sharp 90° corners, reducing stress concentrations that could lead to joint failure over time. The generous radius (0.5-0.75") also simplifies carpet/liner wrapping during finishing.
CNC Precision Manufacturing: Vacaville Craftsmanship
ShopSabre Industrial CNC Routers
Every P12-WS III enclosure begins on one of our ShopSabre industrial CNC routers—precision machinery capable of ±0.005" (five-thousandths of an inch) tolerance. This isn't hobby-grade equipment; these are industrial workhorses used in aerospace, furniture, and architectural millwork industries where dimensional accuracy is non-negotiable.
The CNC process ensures several critical quality factors:
- Absolute Repeatability: Panel #1 and panel #100 are dimensionally identical to within five-thousandths of an inch—impossible with hand tools or table saws
- Complex Geometry Accuracy: The wedge angle, rounded corners, and dado-cut joints are all programmed digitally and executed with machine precision—no human measurement error
- Optimization: CNC nesting software arranges panel cuts to minimize material waste, maximizing yield from each MDF sheet
- Clean Edges: High-speed router bits produce clean, chip-free edges that accept glue more effectively than rough saw cuts
Oregon-Sourced Premium MDF
Not all MDF (Medium Density Fiberboard) is created equal. Proline-X exclusively uses 3/4" premium MDF sourced from Oregon mills, selected for specific properties that matter in subwoofer enclosure applications:
Consistent Density
Oregon MDF maintains 45-50 lb/ft³ density throughout each sheet with minimal variation. Inconsistent density creates acoustically "dead" and "live" zones within enclosure walls, coloring bass response. Premium MDF ensures uniform acoustic properties.
High Bending Strength
At 3/4" thickness, our Oregon MDF exhibits >4000 psi internal bond strength (IB), resisting delamination under bass pressure cycling. Cheaper MDF can literally come apart at the glue lines after months of subwoofer abuse.
Low Moisture Content
Oregon's dry climate and controlled kiln-drying processes produce MDF with 4-8% moisture content—stable and unlikely to warp or swell. Higher moisture content causes dimensional changes that can compromise airtight seals.
Smooth Surface Finish
Premium MDF machines to a smooth surface that accepts carpet and trunk liner adhesives more reliably than rough, porous cheaper materials. The fine particle structure also paints beautifully if you choose custom finishing.
Proprietary Dado-Cut Interlocking Joints
The P12-WS III uses Proline-X's proprietary dado-cut joint system—a critical differentiator from competitors who rely on simple butt joints (two panels glued edge-to-edge with no mechanical interlocking).
Dado Joint Advantages:
- Mechanical Interlocking: A dado is a groove cut into one panel that accepts the edge of another panel, creating a tongue-and-groove style joint. Even without glue, the panels physically interlock, providing inherent structural strength
- Increased Glue Surface Area: Butt joints only contact along the thin edge of the MDF (0.75" width). Dado joints contact along the edge PLUS the walls of the groove (3× to 4× more surface area), creating vastly stronger bonds
- Self-Alignment: Dado grooves guide panels into correct position during assembly, preventing misalignment that could compromise airtight seals
- Shear Resistance: Bass pressure creates shear forces trying to slide panels apart. Dado joints resist shear mechanically through the interlocking geometry, not just through glue strength
For the angled panels in the wedge design, dado cuts are precisely angled to match the 20° taper, ensuring tight mechanical joints even in non-perpendicular configurations.
Pre-Assembly with Titebond II Premium Wood Glue
Every P12-WS III ships fully pre-assembled using Titebond II Premium Wood Glue—not a cost-cutting measure, but a quality control decision that ensures optimal assembly techniques are used rather than relying on end-user skill.
Why Titebond II?
- Water-Resistant Formula: Type II water resistance (ANSI/HPVA Type II) protects against humidity and condensation in trunk environments. Standard wood glues can soften in humid conditions, compromising joints over time
- Strong Initial Tack: Holds panels in position during clamping, preventing shifting that could create gaps or misalignment
- Excellent Gap-Filling: Fills microscopic surface irregularities in MDF, maximizing bond surface area and creating airtight seals
- Non-Creep Formula: Maintains bond strength under sustained loads (bass pressure creates constant stress cycling on joints)
- Sets in 30 Minutes, Cures in 24 Hours: Allows repositioning during initial assembly but reaches full strength quickly
Our assembly technicians apply Titebond II generously to all dado joints and panel edges, clamp assemblies using industrial bar clamps and corner clamps, and allow a full 48-hour cure time before sanding, finishing, and shipping. This attention to assembly detail ensures airtight construction that will never leak bass.
Sealed Enclosure Acoustic Theory
Why Sealed for Accuracy and Musicality
The P12-WS III uses sealed (acoustic suspension) design—a deliberate choice prioritizing accurate bass reproduction over maximum SPL (sound pressure level). Understanding why sealed enclosures excel for music reproduction requires examining the physics of loudspeaker loading.
When a subwoofer driver moves inward (negative excursion), it compresses air inside the enclosure. This compressed air pushes back against the cone, creating a restoring force that behaves like an additional mechanical spring. In sealed enclosures, this "air spring" is perfectly linear—the restoring force increases proportionally with displacement, creating predictable, controlled motion.
Sealed Enclosure Benefits:
Transient Accuracy
The linear air spring allows subwoofers to start and stop precisely with musical transients. Bass notes have distinct attack and decay—sealed enclosures preserve these characteristics. Ported designs have acoustic resonances that continue ringing after the signal stops, blurring transient detail.
Flat Frequency Response
Sealed enclosures exhibit 12 dB/octave rolloff below resonance with minimal ripple or peaking. This smooth response integrates seamlessly with front speakers. Ported enclosures show +3 to +6 dB peaks near tuning frequency, requiring EQ correction.
Minimal Group Delay
Group delay represents the time lag between input signal and acoustic output. Sealed enclosures maintain low, flat group delay across the bass spectrum. Ported designs show significant group delay increases near port tuning, causing bass to sound "slow" or "boomy."
Power Handling Below Tuning
Sealed enclosures maintain acoustic loading at all frequencies. Ported enclosures "unload" below tuning frequency, allowing excessive cone excursion that can damage voice coils. Sealed designs are inherently safer for subwoofers.
1.25 ft³ Volume Optimization
The P12-WS III's 1.25 ft³ net internal volume represents careful optimization for typical 12" subwoofer parameters. This volume provides excellent balance between low-frequency extension, transient response, and system Q (quality factor).
Most 12" subwoofers designed for sealed enclosures specify optimal volumes between 0.75 ft³ and 1.5 ft³. The P12-WS III's 1.25 ft³ falls perfectly in the middle of this range, offering universal compatibility:
- Low-Qts Subwoofers (Qts 0.4-0.5): Underdamped drivers benefit from smaller sealed volumes. 1.25 ft³ provides appropriate acoustic loading, raising system Q to optimal range (0.6-0.7) for extended low-frequency response
- Medium-Qts Subwoofers (Qts 0.5-0.7): Most 12" drivers fall in this range. 1.25 ft³ provides textbook-perfect loading, yielding flat response to ~40 Hz with excellent transient control
- High-Qts Subwoofers (Qts 0.7-0.9): Overdamped drivers designed for very small sealed volumes still perform well in 1.25 ft³, with slightly extended bass at the expense of some transient speed
Acoustic Modeling Examples
Sample Subwoofer Performance in P12-WS III
Example 1: Alpine S2-W10D4 (actually a 10", but illustrative)
Thiele-Small Parameters: Fs 32 Hz, Qts 0.59, Vas 1.42 ft³
In 1.25 ft³ sealed: F3 (−3 dB point) = 42 Hz, Qtc = 0.72
Result: Extended low-frequency response with excellent transient control—ideal for music
Example 2: Image Dynamics ID12 V4 D2
Thiele-Small Parameters: Fs 28 Hz, Qts 0.52, Vas 2.11 ft³
In 1.25 ft³ sealed: F3 = 40 Hz, Qtc = 0.68
Result: Flat response to 40 Hz with tight, accurate bass—perfect for SQ applications
Example 3: JL Audio 12W3v3-4
Thiele-Small Parameters: Fs 32.83 Hz, Qts 0.536, Vas 1.386 ft³
In 1.25 ft³ sealed: F3 = 41 Hz, Qtc = 0.71
Result: JL Audio's recommended sealed volume for this driver is 1.25 ft³—perfect match
Installation Excellence & Real-World Applications
Optimal Wedge Orientation & Positioning
The P12-WS III wedge design is specifically optimized for rear seat installations with the shallow (9.25") edge against the rear seat. This orientation maximizes the space-saving benefits while providing proper acoustic coupling.
Correct Installation:
- Position Verification: Place enclosure in trunk with 9.25" shallow edge against rear seat, 14.5" deep edge toward trunk opening
- Woofer Orientation: Mount subwoofer with cone facing forward (toward rear seat) for maximum cabin coupling, or rearward (toward trunk opening) for maximum output—both work well
- Securing Methods: Heavy-duty Velcro (3M Dual Lock) on bottom panel, cargo straps through trunk tie-down points, or custom brackets secured to trunk floor
- Clearance Check: Ensure 2-3" clearance around port and terminal cup for wiring access and airflow (no acoustic performance requirement, just practical access)
Vehicle Application Examples
Compact Sedans
Examples: Honda Civic, Toyota Corolla, Mazda3, VW Jetta
Challenge: Limited trunk depth (typically 12-15" usable)
Solution: P12-WS III's 9.25" shallow edge fits easily while 14.5" deep section extends into naturally deeper lower trunk area. 16" width fits side-to-side without blocking trunk access.
Mid-Size Sedans
Examples: Honda Accord, Toyota Camry, Nissan Altima, Ford Fusion
Challenge: Balance bass performance with cargo flexibility
Solution: Wedge profile reclaims 3-5" upper trunk space for luggage, groceries, or emergency equipment. 1.25 ft³ volume provides serious bass without overwhelming cabin size.
Coupes & Sports Cars
Examples: Mustang, Camaro, 370Z, BRZ/86, Miata
Challenge: Extremely limited trunk space, steeply angled rear seats
Solution: Wedge geometry perfectly matches aggressive seat recline angles in performance coupes. Compact footprint leaves space for track equipment or travel bags.
Luxury Sedans
Examples: BMW 3/5-Series, Mercedes C/E-Class, Audi A4/A6, Lexus IS/ES
Challenge: Maintaining premium appearance, integrating with factory audio
Solution: Gray trunk liner finish matches OEM trunk materials. Compact profile maintains luxury aesthetic without obvious aftermarket modifications.
Subwoofer Compatibility Guide
The P12-WS III accommodates virtually any 12" subwoofer with these dimensional requirements:
| Parameter | Requirement | Notes |
|---|---|---|
| Mounting Diameter | ≤11.13" (282.7mm) | Standard 12" mounting diameter |
| Mounting Depth | ≤11.0" | Accounts for internal bracing and terminal cup |
| Optimal Sealed Volume | 0.75 - 1.75 ft³ | 1.25 ft³ is middle of range, universal compatibility |
| Power Handling | Any (200W - 1500W+) | Enclosure supports all power levels |
Recommended Subwoofers for P12-WS III:
- SQ-Oriented: Image Dynamics ID12 V4, JL Audio 12W6v3, Dynaudio Esotan 12", Focal Utopia M 12WS, Hertz Mille Pro MP 300 D2
- Balanced Performance: Alpine S2-W12D4, JL Audio 12W3v3, Kicker 44L7S12, Rockford Fosgate P3D4-12
- High-Output: Audiomobile Encore 4412, Sundown SA-12, Skar Audio EVL-12, DC Audio Level 3 12"
- Budget-Friendly: Rockford Fosgate R2D4-12, Kicker 44CWCS124, Pioneer TS-W126M, Alpine Type-S SWS-12D4
Multi-Enclosure Configurations
For enthusiasts seeking maximum bass output, the P12-WS III's compact 16" width allows dual enclosure installations in many trunk applications:
Dual P12-WS III Configuration
Total Width: 32" (two enclosures side-by-side)
Total Power: 2× subwoofers = double the cone area = +6 dB output potential
Impedance Options: Wire subwoofers in series, parallel, or independent channels to match amplifier impedance requirements
Applications: Competition SPL, large sedan/full-size car applications, or enthusiasts who simply want maximum bass impact
Vehicle Compatibility: Most full-size sedans (Charger, 300, Impala, Taurus) and mid-size cars with wide trunks (Accord, Camry, Maxima) can accommodate dual 16" wide enclosures side-by-side with room for amplifier mounting.
Build Quality You Can Feel, Warranty You Can Trust
Hand-Crafted in Vacaville, California
Every P12-WS III enclosure is hand-crafted in our Vacaville, California facility—not mass-produced overseas and imported. This US manufacturing provides several tangible benefits:
- Quality Control: Every enclosure is inspected by the craftsman who built it before leaving our facility. Defects are caught and corrected immediately, not discovered by customers after overseas shipping
- Material Sourcing: Oregon MDF, Titebond adhesives, OFC speaker wire—all domestic materials selected for performance rather than lowest cost
- Lead Times: US manufacturing means 1-3 day production and shipping timelines, not 6-12 week overseas container shipping
- Environmental Standards: California's strict environmental regulations ensure responsible manufacturing practices and VOC-compliant materials
- Supporting US Jobs: Your purchase directly supports American craftspeople and US-based suppliers
Finish Options: Gray or Black
The P12-WS III is available in two premium finish options, both professionally applied during manufacturing:
Dark Gray Trunk Liner
- Material: Durable trunk liner material (same as OEM trunk surfaces)
- Texture: Slightly textured, non-slip surface
- Durability: Excellent resistance to scuffing, scratching, and wear
- Appearance: Matches factory trunk materials in most vehicles—stealth OEM look
- Maintenance: Wipes clean with damp cloth, stain-resistant
- Best For: Installations prioritizing OEM appearance, luxury vehicles, lease vehicles
Plush Black Carpet
- Material: Premium automotive-grade carpet
- Texture: Soft, plush surface with slight nap
- Durability: Good resistance to wear with proper care
- Appearance: Traditional aftermarket subwoofer enclosure aesthetic
- Acoustic Benefit: Slight additional sound damping compared to trunk liner
- Best For: Enthusiasts preferring traditional appearance, show vehicles, visible installations
Rounded Corners: Form and Function
The P12-WS III features generously rounded corners (0.5-0.75" radius) throughout the enclosure—a design detail that serves multiple purposes:
- Easier Installation: Rounded corners slide into place more easily than sharp corners, particularly important in tight trunk spaces or when navigating around wheel wells
- Reduced Snagging: Sharp 90° corners catch on carpet, clothing, and cargo. Rounded corners eliminate this frustration
- Improved Durability: Sharp corners are stress concentrators where impacts can cause chipping or delamination. Rounded corners distribute impact forces more evenly
- Professional Appearance: Rounded corners create a refined, finished look compared to harsh right angles
- Easier Finishing: Applying carpet or trunk liner around rounded corners is significantly easier than sharp corners, resulting in cleaner, more professional appearance
Pre-Installed Premium Components
The P12-WS III arrives ready to install with premium components already integrated:
12-Gauge OFC Speaker Wire
Premium oxygen-free copper speaker wire is pre-installed and routed internally, terminating at the custom terminal cup. 12 AWG is appropriate for subwoofer power levels up to ~1500W RMS, ensuring minimal voltage drop and maximum power transfer.
Custom Terminal Cup
High-power terminal cup features spring-loaded terminals that accept banana plugs, spade terminals, or bare wire. Recessed mounting prevents terminal damage during installation or cargo loading.
Stainless Steel Hardware
All mounting hardware (terminal cup screws, brace fasteners) uses stainless steel for corrosion resistance. Zinc-plated steel hardware can rust in humid trunk environments—stainless ensures long-term reliability.
Internal Bracing
Heavy bracing is strategically placed during assembly to maximize panel rigidity while minimizing internal volume displacement. Braces span the widest dimensions (width and depth) to prevent flexure under bass pressure.
Warranty & Support
Every P12-WS III enclosure is backed by Proline-X's 1-year warranty against internal leaking or joint failure. This warranty reflects our confidence in construction quality—we don't expect failures, but we stand behind our work if they occur.
Warranty Coverage Includes:
- Air leaks due to joint separation or glue failure
- Panel delamination or MDF structural failure
- Terminal cup detachment or failure
- Finish delamination or separation (not scratches/abrasion from normal use)
Warranty Exclusions:
- Cosmetic damage from installation, cargo contact, or normal wear
- Damage from improper subwoofer mounting (over-torqued screws, etc.)
- Modifications or repairs performed by anyone other than Proline-X
- Damage from excessive subwoofer power (thermal damage to speaker wire, etc.)
Third Generation Innovation, Hand-Crafted Excellence
The Proline-X Performance P12-WS III represents the evolution of sealed enclosure design—intelligent wedge geometry that reclaims precious cargo space without sacrificing acoustic performance. CNC-cut with ±0.005" precision. Hand-assembled using Titebond II Premium Wood Glue. Braced for rigidity. Finished to perfection.
This isn't just a box for your subwoofer. It's a precision acoustic instrument hand-crafted in Vacaville, California using ShopSabre industrial CNC routers, premium Oregon MDF, and proprietary dado-cut interlocking joints. Every joint is mechanically interlocked AND glued for airtight construction that will never leak bass. Every brace is strategically placed to prevent panel resonance. Every corner is precisely rounded for easier installation and professional appearance.
The 1.25 ft³ sealed volume provides universal compatibility with virtually any 12" subwoofer—from budget-friendly daily drivers to competition-grade SQ monsters. The wedge profile hugs your rear seat naturally, reclaiming 3-5 inches of upper trunk space while maintaining identical acoustic performance to our rectangular P12-S design.
Available in dark gray trunk liner or plush black carpet. Both finishes are professionally applied and durably bonded for years of service.
Experience the difference that third-generation refinement brings to space-constrained installations. Feel the impact of properly engineered sealed bass response. Enjoy the convenience of 3-5 inches of reclaimed cargo space.
New Release. Third Generation. Hand-Crafted in USA.
Lets Dive Deeper into the Build Quality
Dado & V Cut Construction for Maximum Strength
Preassembled with Titebond II Wood Glue
Rounded Corners for Easy Installation
Custom Terminal Cup with Pre-Installed Wiring
Proline X Performance Wedge P12-WS III Sealed Enclosure for 12" Subwoofers