Proline X
2018 Honda Civic Dual 12 Sealed
SKU: CB 12D-S CIVIC18
- Best For: 2018 Honda Civic, two Wavtech thinPRO 12s
- Net Volume: 0.61 cu ft per chamber (1.23 total)
- Driver Match: Pair of Wavtech thinPRO 12
- Construction: Custom Build | Woofers Up | Two Sealed Chambers | Double 1.5" Top, Gloss Black Acrylic Overlay | 8 Posts | Right-Side Terminal Cup | No Carpet
Financing available. Choose Shop Pay Installments at checkout.
2018 Honda Civic Dual 12 Sealed
More enclosures cut for Wavtech subwoofers: Wavtech Subwoofer Boxes
Custom Build | 2018 Honda Civic Dual 12 Sealed
Two Wavtech thinPRO 12s, Woofers Up, Two Sealed Chambers | 5.00 in Tall
Built for One Car and One Pair of Woofers
This is a Proline X custom build: a flat sealed enclosure for a 2018 Honda Civic, 34 inches wide and 28 inches deep, with the height set by the airspace rather than by a catalogue size. It carries two Wavtech thinPRO 12s firing straight up through a double-layer top, each in its own sealed chamber.
0.61 cubic feet net per chamber, the 0.6 cubic foot optimum Wavtech itself recommends for the thinPRO 12 in a sealed box, rounded up to the sixteenth of an inch of height. On Wavtech's figures (Fs 26 Hz, Qts 0.46, Vas 42 liters) that is Qtc 0.851 with system resonance at 48.1 Hz and half power at 41.3 Hz: firm and punchy, a little above maximally flat.
Two Fully Separate Chambers
A bonded 3/4 inch MDF divider runs front to back at mid-width, so each thinPRO 12 has its own 0.61 cubic feet and neither cone loads the other. Each woofer sits centred over its chamber, 8.69 and 25.31 inches from the left edge and 14 inches back.
How It Is Built
Double-Layer Mounting Surface
The top is two bonded 3/4 inch sheets, 1.5 inches through, under a gloss black acrylic overlay. The woofers surface-mount on it; there is no flush recess.
Flush Edges, No Carpet
No inset side panels: every edge is flush, with the walls seated in 1/4 inch rabbets and dados in the top and bottom. No carpet: the sides and bottom are left bare for custom trim panels.
Post Bracing
Four 3 by 3/4 inch MDF posts per chamber, eight in all, a pair ahead of and a pair behind each woofer. Each post seats in a 1/4 inch pocket in the bottom and in the inner top layer, tying the top to the bottom across the 28 inch spans without splitting the airspace.
Motor Clearance
The thinPRO 12's 3 inch mounting depth reaches 1.5 inches below the double top, leaving 1.25 inches of clearance in the 2.75 inch cavity.
Wiring and Power
One terminal cup is fitted on the right side (a 28 inch side), 7 inches back from the front edge, in the wall of chamber B. Chamber A's leads pass to it through a small sealed hole in the divider, so the two chambers stay separate. The thinPRO12-4 is rated 750 watts RMS; aim for roughly 525 to 750 watts per driver at the impedance you wire. The cutouts are 11.125 inches under the 13.06 inch frame. Wavtech publishes no bolt circle, so the woofers are mounted with a threaded insert kit and stainless machine screws, marked from the driver.
Built in Tennessee, Backed by Audio Intensity
Cut and assembled in Tullahoma, Tennessee on our own CNC equipment from Langboard Elite MDF. The top carries a gloss black acrylic overlay; the rest of the cabinet ships as bare MDF with no carpet, ready for the custom trim panels this install is getting. 1 year limited warranty. Enclosure only, the woofers are purchased separately. Questions about a custom build of your own, call or text 931-563-5151.
2018 Honda Civic Dual 12 Sealed
34 x 28 x 5.00 inches, 0.61 cubic feet net per chamber at Qtc 0.851, F3 41.3 Hz, built to order in Tennessee.
| Specification | Value |
|---|---|
| Build Type | Custom Build Series: 2018 Honda Civic |
| Compatible Driver | Wavtech thinPRO 12, quantity 2 |
| External Dimensions | 34.00" W x 28.00" D x 5.00" H |
| Mounting | Woofers up, surface mount on a double 1.5 in top, no recess |
| Internal Volume, Net | 0.61 cu ft per chamber, 1.23 total, after the posts and 0.042 cu ft driver displacement |
| Alignment per chamber | Qtc 0.851, fc 48.1 Hz, F3 41.3 Hz anechoic |
| Wavtech Recommended | 0.4 to 1.0 cu ft sealed, 0.6 optimum |
| Cutouts | 11.125 in x2 at 8.688 / 25.312 in, 14 in back |
| Motor Clearance | 1.25 in below the 3.0 in mounting depth |
| Bracing | Four 3 x 0.75 in MDF posts per chamber, 8 total |
| Sides | Flush, no inset side panels |
| Terminal Cup | One, right side (28 in side), 7 in from the front edge |
| Driver Mounting | Threaded insert kit included; Wavtech publishes no bolt circle |
| Material | Langboard Elite MDF, rabbet and dado joinery |
| Top Finish | Gloss black acrylic overlay |
| Carpet | None: bare MDF for custom trim panels |
| Shipping Weight | 64 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
0.61 cu ft against a 42.0 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 20.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 26.00 | Hz | free-air resonance |
| Qts | 0.460 | 4 ohm | |
| Vas | 42.00 | L | equivalent compliance |
| Sd | 510.7 | cm² | effective piston area |
| Xmax | 20 | mm | one-way linear travel |
| Pe | 750 | W | continuous RMS |
| SPL | 83.5 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by Wavtech published specifications. 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.
Shop By Series
