Proline X
Performance Optimized Wedge Sealed 15" Enclosure | Audiomobile Encore 4415
SKU: PO 15-S W ENCORE BB
- Best For: Audiomobile Encore 4415 Trunk-Fit Builds
- Net Volume: 1.50 cu ft (1.63 cu ft Gross)
- Alignment: Qtc 0.988, fc 51.1 Hz, F3 40.4 Hz; 1.2 dB rise near 73 Hz, the Encore's own character
- Driver Match: Audiomobile Encore 4415 (dual 4 ohm)
- Construction: Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | Threaded Insert Kit included
Financing available. Choose Shop Pay Installments at checkout.
Performance Optimized Wedge Sealed 15" Enclosure | Audiomobile Encore 4415
Performance Optimized Wedge | Audiomobile Encore 4415
15" Sealed Wedge Enclosure | Rear-Firing Trunk-Load Design
The Audiomobile Encore 4415 in a Sealed Wedge
The Encore 4415 is Audiomobile's low-profile 15 inch subwoofer: 5.9 inches of mounting depth on a cast aluminum frame, a 3 inch dual 4 ohm voice coil, 1000 watts RMS and 2000 watts maximum, 19.1 mm of one-way excursion at 70 percent Bl, a composite sandwich cone with a carbon fiber dust cap. Every figure comes from Audiomobile's own Encore Series specification sheet, the Klippel data measured with the two 4 ohm coils in parallel, which reproduces its own moving mass and compliance. Dealer tables print a second, different parameter set for this driver; it is not used here.
1.50 cubic feet net sits in the middle of Audiomobile's 1.25 to 1.8 cubic feet sealed range for the Audiomobile Encore 4415. The Encore 4415 is a high-Qts driver by design: with Qts 0.625 against 2.25 cubic feet of Vas it lands at Qtc 1.05 at Audiomobile's 1.25 cubic foot minimum and 0.94 at the top of the range, and a maximally flat box would take about 8 cubic feet. In this cabinet it sits at Qtc 0.988 with system resonance at 51.1 Hz, half power at 40.4 Hz and a 1.2 dB rise centred near 73 Hz. That rise is the impact Audiomobile builds the Encore for, and this page shows that curve rather than a flat one.
Trunk-Load Wedge Design Explained
The driver mounts on the vertical trunk-lid-side face and fires rearward into the trunk cavity.
Seat-Side Face Matches Seat Lean
Angled face matches the roughly 20 degree factory seat lean.
Trunk-Lid-Side Face Fires the Woofer
Vertical baffle, cone firing rearward into the trunk cavity.
Trunk Cavity Loading
The trunk acts as an acoustic extension for a smoother presentation.
Preserves Trunk Cargo Space
The wedge tucks against the seat back and the space in front stays usable.
Engineered for the Audiomobile Encore 4415
Half power lands at 40.4 Hz anechoic, before any cabin gain. Audiomobile publishes the cone area outright, 819.40 square centimeters, and the excursion, 19.1 mm each way. The driver displacement, 0.12 cubic feet, is not on Audiomobile's sheet and is an estimate; it only affects the gross figure, the net airspace is what the cabinet was cut to.
Alignment Numbers
| Driver | System Qtc | fc | F3 |
|---|---|---|---|
| Encore 4415, dual 4 ohm coils in parallel | Qtc 0.988 | 51.1 Hz | 40.4 Hz |
Mounting Geometry
Vertical baffle CNC cut to 14.00 in (356 mm), the cutout Audiomobile prints. The rear panel rakes 20 degrees, so the cavity deepens from 6.76 in at the top to 13.31 in at the base, and the 5.9 in motor clears it with 0.75 in to spare above its top edge. The cosmetic recess is cut to Audiomobile's published 15.50 in frame. Audiomobile publishes no mounting hole locations for the Encore, so the baffle ships undrilled with a threaded insert kit and stainless machine screws: set the driver in the recess, mark its holes, drill, press the inserts and bolt it down.
What the Numbers Rest On
Langboard Elite MDF
Premium 3/4 in MDF throughout.
V-Groove and Dado Joinery
CNC cut V-grooves at every panel intersection, sides and brace seated in dados.
Double-Layer 1.5" Front Baffle
Two bonded 3/4 in MDF sheets at the driver face, the outer layer machined as a flush recess.
Audiomobile's Own Sheet
Fs 32.3 Hz, Qts 0.625, Qes 0.659, Qms 11.827, Vas 63.70 L, Sd 819.40 cm2, Mms 335.99 g, Cms 0.067 mm/N, Bl 13.5 T-m, coils in parallel. Reference efficiency 0.313 percent, about 87.0 dB at 1 W derived from it.
Wiring the Audiomobile Encore 4415 to Your Amplifier
The Encore 4415 carries two 4 ohm voice coils: wire them in parallel for a nominal 2 ohm load (1.71 ohm DC, the configuration Audiomobile measured) or in series for 8 ohms. Confirm the final load against your amplifier's minimum stable impedance before powering the system.
Power handling is 1000 watts RMS per driver. Aim for roughly 700 to 1000 watts at the impedance you wire.
Built in Tennessee, Backed by Audio Intensity
Cut and assembled in Tullahoma, Tennessee on our own CNC equipment. Finished in plush black carpet with the gloss black acrylic baffle insert, one pre-wired terminal cup, 12 gauge OFC to the driver position. Polyfill wall lining installed. Threaded insert kit and stainless machine screws in the box. 1 year limited warranty. Enclosure only, the driver is purchased separately. Call or text 931-563-5151.
Audiomobile Encore 4415: Built to 1.50 Cubic Feet
Qtc 0.988, F3 40.4 Hz, cut direct fit to the Encore 4415 and built to order in Tennessee.
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Wedge |
| Compatible Driver | Audiomobile Encore 4415, quantity 1. Direct fit |
| Configuration | Single 15 inch, single chamber sealed wedge |
| Mounting Position | Trunk or cargo area, tall face against the rear seat back |
| Firing Direction | Rearward into the trunk. Not a down fire design, no feet included |
| External Width | 26.79 in |
| External Height | 18 in at the seat face |
| External Depth | 13.31 in at the base, tapering to 6.76 in at the top |
| Internal Volume, Gross | 1.63 cu ft |
| Internal Volume, Net Acoustic | 1.50 cu ft after the brace and an estimated 0.12 cu ft driver displacement |
| Driver Mounting Depth | 5.9 in required; 0.75 in clearance above the motor against the raked rear panel |
| Audiomobile Sealed Range | 1.25 to 1.8 cubic feet; sheet minimum 1.2 cu ft (35 L) |
| Alignment | Qtc 0.988, fc 51.1 Hz, F3 40.4 Hz anechoic; 1.2 dB rise near 73 Hz |
| Butterworth Volume | About 8 cu ft, not a practical box for this driver; every volume in Audiomobile's range sits near Qtc 1.0 |
| Woofer Opening | 14.00 in (356 mm) direct fit |
| Frame Outer Diameter | 15.50 in (394 mm), Audiomobile spec |
| Bolt Circle | Not published by Audiomobile; see Driver Mounting |
| Driver Displacement | 0.12 cu ft, estimated; not on Audiomobile's sheet |
| Fs / Qts / Qes / Qms | 32.3 Hz / 0.625 / 0.659 / 11.827, coils in parallel |
| Vas / Mms / Cms / Bl | 63.70 L / 335.99 g / 0.067 mm/N / 13.5 T-m |
| Driver Sd | 819.40 cm2, published by Audiomobile |
| Xmax | 19.1 mm one way at 70 percent Bl; 46 mm peak to peak mechanical |
| DC Resistance | 1.71 ohm with the 4 ohm coils in parallel |
| Driver Sensitivity | Reference efficiency 0.313 percent, Audiomobile spec; about 87.0 dB at 1 W derived from it |
| Driver Power Handling | 1000 W RMS / 2000 W maximum |
| Wiring Options | Dual 4 ohm coils: 2 ohm in parallel, 8 ohm in series |
| Voice Coil | 3 in (76 mm) dual 4 ohm, Le 0.965 mH at 1 kHz |
| Parameter Source | Audiomobile Encore Series specification sheet (Klippel data); dealer tables print a second set that is not used |
| Material | Langboard Elite MDF |
| Construction | CNC cut, V-groove and dado joinery |
| Panel Thickness | 0.75 in |
| Front Baffle | 1.5 in double baffle, outer layer machined as a flush recess |
| Internal Bracing | Windowed brace, dadoed to the shell |
| Driver Mounting | Threaded insert kit included, NOT pre-installed: Audiomobile publish no mounting hole locations |
| Terminal Cups | One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC |
| Acrylic Insert | Gloss black acrylic baffle insert standard; None variant minus $20 |
| Damping | Light polyfill wall lining, does not alter acoustic volume |
| Carpet | Plush black |
| Shipping Weight | 48 lb |
| Warranty | 1 Year Limited |
| Built In | Tullahoma, Tennessee |
01Is it a sealed driver?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
1.50 cu ft against a 63.7 L Vas.
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 19.1 mm, and in this alignment a subsonic filter barely moves it.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 32.30 | Hz | free-air resonance |
| Qts | 0.625 | 4415, dual 4 ohm coils in parallel | |
| Vas | 63.70 | L | equivalent compliance |
| Sd | 819.4 | cm² | effective piston area |
| Xmax | 19.1 | mm | one-way at 70 percent Bl, Audiomobile's own basis |
| Pe | 1000 | W | continuous RMS |
| SPL | 87.0 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by Audiomobile Encore Series specification sheet (Klippel data). Curves computed against this enclosure’s actual net airspace.
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.
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, 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.
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.
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.
Handcrafted in USA
Hand-assembled at our facility in Tullahoma, TN. Every enclosure is inspected before it ships.
Tuned to the Build
Internal volume and port geometry are calculated to spec and CNC-cut to exact dimensions. The box performs the same way every time.
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