Proline X
Proline X Micro Series 10" Sealed Enclosure - Fits Alpine RSW10
SKU: M10-S Alp
- Best For: Daily-driver installs — under-seat and behind-seat trucks, tight trunk and cargo builds
- Power: Rated for up to 600W RMS (Alpine RS-W10D4)
- Topology/Class: Sealed / Double-Layer Stack Fab / Dowel Reinforced / Front-Fire or Downfire
- Sonic Character: Warm, impactful daily-driver bass — high-Qts driver delivers strong upper-bass presence in a 5.25" compact sealed build
Financing available — choose Shop Pay Installments at checkout.
Proline X Micro Series 10" Sealed Enclosure - Fits Alpine RSW10
Built for the Alpine RS-W10D4.
0.50 cu ft. 5.25" Deep.
The Alpine RS-W10D4 is a high-Qts shallow-mount driver — 600 watts RMS, 20mm Xmax, and a Qts of 1.19 that makes it forgiving in compact sealed enclosures and naturally impactful in daily-driver applications. The Proline X Micro Series enclosure delivers 0.50 cubic feet of sealed airspace in a double-layer stack-fab build that is 5.25 inches deep — the same shell as the JL 10TW3 build, matched to the Alpine's specific cutout geometry.
High-Qts Driver, Compact Sealed Box — What That Actually Means
The Alpine RS-W10D4 has a published Qts of 1.19 — one of the highest in the Micro Series lineup. A high Qts in a sealed enclosure produces an elevated system Qtc, which means the driver's low-frequency output rises gently before rolling off rather than dropping flat at the box resonance. At 0.50 cubic feet, the RS-W10D4's system Qtc will be well above 1.0 — which produces a warm, impactful bass character with good efficiency in the upper bass range.
Alpine publishes three sealed volume targets for this driver: 0.54 cu ft for a -3dB point at 32 Hz, 0.79 cu ft for -3dB at 30 Hz, and 1.04 cu ft for -3dB at 28 Hz. At 0.50 cubic feet this enclosure falls just below the smallest published target, which shifts the effective extension point slightly upward in exchange for maximum output efficiency in the 50–80 Hz range. For a daily-driver under-seat or behind-seat install, this is the practical tradeoff — a compact box that punches hard where the listener feels it most. If deeper anechoic extension is the priority, the larger published volumes require a box this format cannot deliver.
Double-Layer 1.5" Baffle — Stack Fab, Dado Joinery, Dowel Reinforced
The front baffle is a double-layer stack-fab build — two CNC-cut Langboard Elite MDF panels bonded to 1.5 inches total thickness. At 600 watts RMS and 20mm Xmax on a 10" cone, the baffle carries a sustained mechanical load that a single 3/4" panel will resonate under over time. Two bonded layers eliminate baffle resonance at the structural level. The stack-fab assembly is further reinforced with dowels throughout, adding mechanical alignment and shear resistance at every panel joint beyond what dado joinery and adhesive alone provide.
Every panel joint uses CNC-cut interlocking dado slots — mechanical interlock before adhesive, adhesive seal after. The 5.25-inch total depth is the same shell geometry as the JL 10TW3 enclosure, with the baffle machined to the Alpine's specific cutout diameter rather than the JL's tab-ear geometry.
0.50 cu ft — Compact and Output-Efficient
At 0.50 cubic feet, the RS-W10D4's high Qts produces a warm, elevated Qtc that maximizes output efficiency in the upper bass range. Alpine's smallest published sealed target is 0.54 cu ft — this enclosure lands just below, producing a slightly elevated Qtc that suits daily-driver impact-focused installs.
5.25" Total — 3.25" Driver Clearance with Margin
The RS-W10D4 requires 3.25" of mounting depth. The enclosure provides sufficient clearance for the driver's rear motor structure at full excursion. At 5.25" total depth this enclosure fits behind and under seats where conventional 10" sealed boxes cannot.
1.5" Double-Layer — Dowel Reinforced Stack Fab
Two bonded layers of Langboard Elite 3/4" MDF at 1.5 inches total, further reinforced with dowels throughout the stack-fab assembly. At 600 watts RMS, baffle resonance at the panel level adds coloration — double-layer construction with dowel reinforcement eliminates it.
8/32 Threaded Inserts — Machine Screws Included
The baffle is fitted with 8/32 threaded inserts on the back face. Stainless machine screws are included. The RS-W10D4 mounts to steel — not MDF. Consistent clamping force, no stripping risk, and clean driver reinstallation when service is needed.
Proline X Terminal Cup — Pre-Wired with 12g OFC
The Proline X terminal cup is installed and pre-wired with 12-gauge OFC run internally to the driver location. Connect your amplifier run to the terminal and mount the driver — no internal wiring work required.
Direct-Fit Alpine Geometry — Standard Round Flange
The RS-W10D4 uses a standard round mounting flange. The baffle cutout is machined to the Alpine's specific cutout diameter — the driver seats flush, seals against the gasket, and mounts to the threaded inserts without shimming or modification.
Front-Firing or Downfiring — Feet Included
Rubber feet for downfiring installation are included. Run it front-firing in a standard orientation or flip it downward to couple bass output with the vehicle floor. Downfiring is effective in truck cabs and SUVs where floor coupling enhances the perceived bass response.
Polyfill Pre-Installed
Polyfill is packed and installed at the factory. It acoustically increases the effective internal volume, extending low-frequency output without adding external size. Factory installation ensures consistent packing density across every unit.
Dowel-Reinforced Stack Fab — Mechanical Strength at Every Joint
Dowels throughout the stack-fab assembly add mechanical alignment and shear resistance at panel joints independent of adhesive condition. Combined with dado joinery and adhesive, every joint in this enclosure is locked by three independent mechanical systems.
Ready to Mount. Ready to Wire. Ready to Downfire.
The enclosure ships fully prepped. The Proline X terminal cup is installed and pre-wired with 12-gauge OFC — connect your amplifier run and wiring is complete. The double-layer baffle uses 8/32 threaded inserts with stainless machine screws included. Rubber feet for downfiring are included. Polyfill is already factory-installed.
Impedance Options — D4 Wiring
The RS-W10D4 has dual 4-ohm voice coils. Wire the two coils in parallel for a 2-ohm load, or in series for an 8-ohm load. Most builds run parallel at 2 ohms into a 2-ohm-stable monoblock in the 400–600 watt RMS range. Confirm your amplifier's stable impedance before wiring. The RS-W10D4's high Qts means it will produce audible output even when moderately underpowered — it is a forgiving driver to match.
Where It Fits
At 21.5" × 14.5" × 5.25", this enclosure fits in the same tight installations as the JL 10TW3 version of the same shell. Common placements:
- Under-seat — extended cab and crew cab trucks
- Behind-seat — full-size truck cabs (front-firing or downfire)
- Trunk corners — compact and mid-size sedans
- Side cargo panels — SUVs and crossovers
- Hatch floor — sports cars and hatchbacks
- Spare tire well — select SUV and crossover platforms
All Proline X Micro Series enclosures carry a two-year manufacturer's warranty against defects in materials and workmanship. Built and inspected in our Tullahoma, Tennessee facility before shipment. Contact Audio Intensity directly for warranty support.
Made in Tennessee
Every Proline X Micro Series enclosure is CNC-cut and hand-assembled in Tullahoma, Tennessee on ShopSabre CNC routers. Internal volume, cutout geometry, dado joint depth, baffle layer count, dowel placement, and terminal positioning are all held to spec on every unit. Langboard Elite MDF throughout — named, mill-documented, published density and bond specifications.
| Compatible Driver | Alpine RS-W10D4 (Dual 4-Ohm) |
| Enclosure Type | Sealed |
| Internal Volume (Net) | 0.50 Cubic Feet |
| Material | Langboard Elite 3/4" MDF |
| Construction | CNC-Cut Stack Fab / Dado Joinery / Dowel Reinforced |
| Front Panel Thickness | 1.5 Inches (Double-Layer Stack Fab) |
| External Width | 21.5 Inches |
| External Height | 14.5 Inches |
| External Depth | 5.25 Inches |
| Max Mounting Depth | 3.25 Inches |
| Woofer Opening | Direct Fit — Alpine RS-W10D4 |
| Driver Mounting | 8/32 Threaded Inserts — Stainless Machine Screws Included |
| Terminal Cup | Proline X Terminal Cup — Pre-Wired |
| Internal Wiring | 12-Gauge OFC (Oxygen-Free Copper) |
| Polyfill | Pre-Installed |
| Firing Direction | Front-Firing or Downfiring |
| Downfire Feet | Included |
| Finish | Plush Black Automotive Carpet |
| Warranty | 2 Years — Proline X / Audio Intensity |
| Made In | Tullahoma, Tennessee, USA |
Built From a Spec Sheet, Not a Sales Sheet
Every Proline X Micro 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 across the 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 — 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 stack-fab layering 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 Micro 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.