Proline X
AudioControl Space SPC-12 Dual Box: Sealed 12" Shallow Wedge Enclosure
SKU: PO 12D-S W SPC12 BB
- Best For: Dual AudioControl Space SPC-12 Trunk-Fit Builds
- Net Volume: 1.25 cu ft per chamber (2.69 cu ft Gross Total)
- Driver Match: Pair of AudioControl Space SPC-12 (SPC-12S2 (single 2 ohm) and SPC-12S4 (single 4 ohm)), matched
- Construction: Dual Chamber | Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | 1 Shared Terminal Cup | Insert Kit
Financing available. Choose Shop Pay Installments at checkout.
AudioControl Space SPC-12 Dual Box: Sealed 12" Shallow Wedge Enclosure
Performance Optimized Wedge | Dual AudioControl Space SPC-12
Dual 12" Sealed Wedge Enclosure | Rear-Firing Trunk-Load Design
A Pair of AudioControl Space SPC-12 in a Sealed Wedge
The SPC-12 is AudioControl's 12 inch Space low-profile: a fiber matrix injection-molded polypropylene cone, a weather-resistant build, a three-layer high-temperature coil former and a wrap-sealed rubber gasket, with a removable grille, rated 400 watts RMS with 9 mm of one-way excursion, 3.94 inches of mounting depth on a 12.37 inch frame. Every Thiele-Small figure comes from AudioControl's own Space Series user guide, one full parameter block per coil, and each block holds together on Qts, moving mass, cone area and sensitivity. AudioControl measures the 2 ohm and 4 ohm versions as separate drivers, and they differ, so each is aligned on its own figures below.
1.25 cubic feet net per chamber on AudioControl's published figures: the SPC-12S2 (single 2 ohm) reads Qtc 0.743 with resonance at 49.1 Hz and half power at 46.8 Hz, and the SPC-12S4 (single 4 ohm) reads Qtc 0.850 with resonance at 52.3 Hz and half power at 44.9 Hz. One cabinet serves both coils. That is AudioControl's own recommended sealed size for this driver, 1.25 cubic feet, between their 0.8 minimum and 1.7 maximum. That is a touch above maximally flat: a small lift near resonance and firm midbass.
Two Fully Separate Chambers
A bonded full-height 3/4 inch MDF divider splits the cabinet into two sealed chambers of 1.25 cubic feet net each, so every driver sees exactly the airspace printed on this page. Two drivers sharing one volume load each other; the divider removes that, and each chamber carries its own polyfill.
The cabinet is pinned at the 32 inch dual width cap, 16 inches tall, 10.96 inches deep at the top and 16.79 at the base, with the depth absorbing the airspace. One shared side-mounted terminal cup feeds both driver positions.
Trunk-Load Wedge Design Explained
The drivers mount on the vertical trunk-lid-side face and fire 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 Woofers
Vertical baffle, cones 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 a pair of AudioControl Space SPC-12
Anechoic half power lands at 46.8 Hz on the SPC-12S2 (single 2 ohm) and 44.9 Hz on the SPC-12S4 (single 4 ohm), before any cabin gain. AudioControl publishes the driver displacement, 0.0619 cubic feet, and it is taken out of the net figure for each driver.
Alignment Numbers (Per Chamber)
| Driver (per chamber) | System Qtc | fc | F3 |
|---|---|---|---|
| Space SPC-12 SPC-12S2 (single 2 ohm) | Qtc 0.743 | 49.1 Hz | 46.8 Hz |
| Space SPC-12 SPC-12S4 (single 4 ohm) | Qtc 0.850 | 52.3 Hz | 44.9 Hz |
Mounting Geometry
The baffle is cut to 11.100 in for AudioControl's 12.370 in frame. The rear panel rakes 20 degrees, so the cavity deepens from 10.96 in at the top to 16.79 in at the base, and the 3.94 in motor clears it with 6.53 in to spare. AudioControl prints no bolt circle for the SPC-12, so the baffle ships undrilled with a threaded insert kit and stainless machine screws: set the driver in its recess, mark its holes, drill and press the inserts.
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 divider 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.
AudioControl's Published Parameters
SPC-12S2 (single 2 ohm): Fs 27.843 Hz, Qts 0.4216, Qes 0.4703, Qms 4.0762, Vas 74.5578 L, Mms 159.609 g, Bl 10.3379 N/A, Re 1.8 ohm. SPC-12S4 (single 4 ohm): Fs 30.7061 Hz, Qts 0.4996, Qes 0.5764, Qms 3.7494, Vas 67.1494 L, Mms 145.71 g, Bl 12.4924 N/A, Re 3.2 ohm. Cone area 511 cm2. Xmax 9 mm (one-way, method not stated).
Wiring a pair of AudioControl Space SPC-12 to Your Amplifier
AudioControl sells the SPC-12 as SPC-12S2 (single 2 ohm) and SPC-12S4 (single 4 ohm); a matched pair should share a coil. A pair of single 2 ohm drivers lands on 1 ohm in parallel or 4 ohms in series. A pair of single 4 ohm drivers lands on 2 ohms in parallel or 8 ohms in series. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for, so series wiring is the safe default. Confirm the final load against your amplifier's minimum stable impedance before powering the system.
Power handling is 400 watts RMS per driver, 800 across the pair. Aim for roughly 280 to 400 watts per driver 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 shared pre-wired terminal cup, 12 gauge OFC to both driver positions. Polyfill wall lining installed. Threaded insert kit and stainless machine screws included (AudioControl publishes no bolt circle). 1 year limited warranty. Enclosure only, the drivers are purchased separately. Call or text 931-563-5151.
Dual AudioControl Space SPC-12: Cut for One Driver
1.25 cubic feet net per chamber at Qtc 0.74 to 0.85, F3 46.8 Hz on the SPC-12S2 (single 2 ohm) and 44.9 Hz on the SPC-12S4 (single 4 ohm), cut direct fit and built to order in Tennessee.
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Wedge |
| Compatible Driver | AudioControl Space SPC-12 (SPC-12S2 (single 2 ohm) and SPC-12S4 (single 4 ohm)), quantity 2. Direct fit |
| Configuration | Dual 12 inch, two separate chambers, 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 | 32.00 in |
| External Height | 16 in at the seat face |
| External Depth | 16.79 in at the base, tapering to 10.96 in at the top |
| Internal Volume, Gross | 2.69 cu ft total |
| Internal Volume, Net Acoustic | 1.25 cu ft per chamber after the divider and the driver displacement |
| Driver Mounting Depth | 3.94 in required; 6.53 in clearance above the motor against the raked rear panel |
| Alignment, SPC-12S2 (single 2 ohm) per chamber | Qtc 0.743, fc 49.1 Hz, F3 46.8 Hz anechoic |
| Alignment, SPC-12S4 (single 4 ohm) per chamber | Qtc 0.850, fc 52.3 Hz, F3 44.9 Hz anechoic |
| Woofer Opening | 11.100 in, two, cut for AudioControl's frame |
| Frame Outer Diameter | 12.370 in |
| Bolt Circle | Not published by AudioControl; threaded insert kit included |
| Driver Displacement | 0.0619 cu ft, AudioControl spec |
| SPC-12S2 (single 2 ohm) Fs / Qts / Qes / Qms / Vas | 27.843 Hz / 0.4216 / 0.4703 / 4.0762 / 74.5578 L |
| SPC-12S4 (single 4 ohm) Fs / Qts / Qes / Qms / Vas | 30.7061 Hz / 0.4996 / 0.5764 / 3.7494 / 67.1494 L |
| Driver Sd | 511 cm2, AudioControl spec |
| Xmax | 9 mm, one-way, method not stated |
| Driver Power Handling | 400 W RMS per driver |
| Wiring Options | AudioControl sells the SPC-12 as SPC-12S2 (single 2 ohm) and SPC-12S4 (single 4 ohm); a matched pair should share a coil. A pair of single 2 ohm drivers lands on 1 ohm in parallel or 4 ohms in series. A pair of single 4 ohm drivers lands on 2 ohms in parallel or 8 ohms in series. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for, so series wiring is the safe default. |
| Parameter Source | AudioControl Space Series user manual |
| 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 | Full-height 3/4 in divider |
| Driver Mounting | Threaded insert kit and stainless machine screws included; inserts set at install, no bolt circle is published |
| Terminal Cups | One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC to both driver positions |
| Acrylic Insert | Gloss black acrylic baffle insert standard; None variant minus $20 |
| Damping | Light polyfill wall lining in both chambers, does not alter acoustic volume |
| Carpet | Plush black |
| Shipping Weight | 59 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
1.25 cu ft against a 74.6 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 9.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 27.84 / 30.71 | Hz | free-air resonance |
| Qts | 0.422 / 0.500 | SPC-12S2 / SPC-12S4 | |
| Vas | 74.56 / 67.15 | L | equivalent compliance |
| Sd | 511.0 | cm² | effective piston area |
| Xmax | 9 | mm | one-way, method not stated |
| Pe | 400 | W | continuous RMS |
| SPL | 87.2 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by AudioControl user manual. 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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