Proline X

Professional Series Ported 15" Enclosure | Skar Audio EVL-15

Q: Do I need a subsonic filter?

Yes, at 27 Hz, 24 dB per octave. Below tuning a vented box stops loading the cone and excursion runs away toward DC. With the filter in place this cabinet puts the Skar Audio EVL-15 at 43 percent of its usable travel at 1500 W.

Q: Would a sealed box be better for me?

Below about 23 Hz, yes. The maker's recommended sealed box is louder down there by up to 3.2 dB, because a sealed box rolls off gently into the subsonic region where a vented one falls away steeply once it is under tuning. Above that this alignment is the louder of the two for the same power. The Performance Graphs tab plots this cabinet, 2.30 cubic feet vented at 34.5 Hz, against Skar Audio's recommended range (low end) sealed box, 3.00 cu ft, so you can see exactly where they cross.

Q: How does the front port work?

It is a vertical slot beside the woofer, the full height of the cavity, 3.00 inches wide and 49.5 square inches. It runs 7.75 inches to the back wall and turns once along it for 23.21 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 17.3 metres per second at 1500 W, 32 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 12.2 metres per second against the 17 metres per second threshold where a slot starts to chuff.

Q: What does the price cover, and how does it ship?

68 lb, 36.00" W x 18.00" H x 14.50" D external. Every Professional cabinet is priced the same way, by its size: this one is 5.44 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 68 lb parcel and checkout adds nothing. The Performance Optimized 15 inch ported wedge is $499.99. The $67 difference is the larger box and the port this driver needs to run at its rating. Do not add polyfill; it ships dry on purpose.

Q: Is the EVL-15 included?

No. This is an enclosure only, cut for the Skar Audio EVL-15 specifically: the 14.000 inch cutout, the 8.540 inch mounting depth allowance and the 2.30 cubic foot alignment all come from Skar Audio's published parameters. It fits both coil versions (D2 and D4), and the cabinet was checked against both. Bring your own driver.

SKU: Pro 15-P EVL15

QUICK SPECS

Alignment: 2.30 cu ft net vented at 34.5 Hz. F3 30.7 Hz anechoic, 2.43 dB passband ripple
Driver: Skar Audio EVL-15 D2/D4, 1250 W RMS, 23.5 mm Xmax, 35.00 Hz Fs
Build: Front-firing standard box, 2.25" three-layer baffle with the woofer flush-mounted in the outer layer, Skar Audio logo acrylic, dado joinery, 49.5 sq in front slot port beside the woofer with one bend along the back wall, port and excursion gated at 1500 W
Cabinet: 36.00" W x 18.00" H x 14.50" D, 68 lb, threaded insert kit included

Shipping Included No freight charges at checkout on US orders. International orders are quoted live carrier rates at checkout.

Built in Tennessee CNC cut from 3/4" Langboard Elite MDF. V-groove and dado joinery.

Advanced Terminal Cup Built in-house. ABS/Carbon Fiber. Stainless steel hardware. Copper ring terminals.

$ 566.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Complete Your System

Wavtech Wavtech link1000.1mini 1000w monoblock amplifier $ 399.99

Professional Series Ported 15" Enclosure | Skar Audio EVL-15

$ 566.99

Enclosure Type Ported

External Dimensions 36.00" W x 18.00" H x 14.50" D

Gross Volume 3.79 cu ft

Net Volume 2.30 cu ft

Tuning Frequency 34.5 Hz

Port Area 49.5 Square Inches

Shipping Weight 76 lbs

INSTALLER'S TAKE

I built this box for one EVL-15 on the full Professional chassis: three layers of baffle with the frame flush in the outer one, and a slot port that runs along the back wall to put 34.5 Hz in a 14.5 inch deep box.

One cabinet serves both coils. It was solved so the EVL-15 D2 and the EVL-15 D4 each pass every velocity, excursion and ripple gate in the same box.

Skar publishes no bolt circle, so the box ships with a threaded insert kit rather than pressed inserts.

1250 watts RMS by Skar's rating. The D2 wires to 4 ohms in series or 1 ohm in parallel; the D4 to 8 ohms series or 2 ohms parallel. Skar Audio publishes no mounting hole locations for the EVL-15, so the inserts are not in the baffle when the box arrives. The insert kit is in the box: set the inserts where the woofer's own holes fall, with the drill bit and the 2.5 inch allen-head screws in the kit, and lay the gasket tape before the woofer goes down.

It ships dry. Do not add polyfill to a ported box. Set your subsonic filter at 27 Hz.

Product Details

Proline X Professional 15" Ported

One EVL-15 in a front-firing box, vented at 34.5 Hz on a three-layer flush-mount baffle

2.30 cu ft net Tuned 34.5 Hz F3 30.7 Hz 2.25" three-layer baffle Cut for the EVL-15 Built in Tennessee

2.30cu ft net

34.5Hz tuning

30.7Hz F3 anechoic

49.5sq in port area

Why this driver is vented at 34.5 Hz

The EVL-15 is Skar's 15 inch at 35.0 Hz, a Qts of 0.63, 46.0 litres of Vas and 1250 W RMS. This cabinet gives it 2.30 cubic feet net behind a 2.25 inch three-layer baffle, vented at 34.5 Hz through a 49.5 square inch slot beside the woofer, for an anechoic F3 of 30.7 Hz in a 36 by 18 by 14.5 inch front-firing box.

Threaded insert kit ships with this box. Skar Audio does not publish the mounting hole locations for the EVL-15, so we cannot install the threaded inserts before it ships. The threaded insert kit comes in the box instead: inserts sized to the woofer, the correct drill bit, 2.5 inch allen-head screws, an allen key and woofer gasket tape. You set the inserts when you mount the woofer, and this box ships with one kit.

Sealed, the EVL-15 needs 6.26 cubic feet net to reach a Qtc of 0.707. Vented, it trades that for deeper extension. The slot is gated at 1500 W, 1.2 times Skar's rating: the channel runs 17.3 m/s and the mouth 12.2, and the cone peaks at 10.1 of its 23.5 mm with the subsonic filter in place. Skar's own ported recommendation is 3.50 to 3.75 cubic feet at 31 Hz, before driver and port displacement.

What makes it Professional

Three-layer baffle, flush mount

Three layers of 3/4 inch Langboard Elite make a 2.25 inch front. The outer layer is routed to the flange, so the woofer sits flush with the face; the two layers behind it carry the mounting hardware and the load.

Skar Audio logo acrylic

A glossy black acrylic insert with the Skar Audio mark sits in the outer layer beside the woofer. It is standard on every Professional cabinet.

Threaded insert kit ships with this box

Threaded insert kit included, inserts NOT pre-installed: the manufacturer publishes no mounting hole locations, so the kit ships with the box for installation when the woofer goes in: 8 to 12 inserts sized to the woofer, the correct drill bit, 2.5 inch allen-head screws, allen key and gasket tape.

Port gated at 1500 W

The 49.5 square inch slot beside the woofer is sized so the channel runs 17.3 metres per second and the mouth 12.2 metres per second at 1.2 times the driver's rating, under the 17 metres per second where a slot starts to chuff. The channel runs 7.75 inches along its wall and turns once along the back wall for another 23.21 inches, which is why a 34.5 Hz tuning fits a 14.50 inch deep box.

Why this is a Professional build

The EVL-15 also builds in the Performance Optimized ported wedge, the smaller and cheaper box. The Professional cabinet is the step up for it: a 2.25 inch three-layer baffle with the woofer flush in the outer layer, and a slot port gated at 1500 W.

What the price covers

Every Professional cabinet is priced the same way, by its size: this one is 5.44 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 68 lb parcel and checkout adds nothing. The Performance Optimized 15 inch ported wedge is $499.99. The $67 difference is the larger box and the port this driver needs to run at its rating.

The cabinet

36.00" W x 18.00" H x 14.50" D external. Two windowed braces run front to back either side of the woofer, clearing the cutout by two and a half inches. The box ships dry: polyfill detunes a ported alignment. Inside the 36 by 18 Professional envelope for a single 15, 14.5 inches deep. 15.50 inch frame, flush in the outer baffle layer, 14.00 inch cutout, 8.54 inches of mounting depth. It ships as a parcel.

Skar publishes a full Thiele-Small table for the EVL-15 on its product page, including a one-way Xmax of 23.5 mm. Some of it is softer than it looks. Skar gives no driver displacement anywhere, so 0.204 cubic feet is our estimate from comparable 15 inch woofers; it moves the tuning by a fraction of a hertz. Skar does not say how the Xmax was measured, so we size port and power against it rather than past it. Also: Skar publishes no outside frame diameter for its 15s; 15.50 inches is our estimate from the 14.00 inch cutout, and the baffle is sized with margin for it. Tuning includes a 1.5 Hz fold loss that is an estimate, not a bench measurement. Skar Audio does not publish the mounting hole locations for the EVL-15, so we cannot install the threaded inserts before it ships. The threaded insert kit comes in the box instead: inserts sized to the woofer, the correct drill bit, 2.5 inch allen-head screws, an allen key and woofer gasket tape. You set the inserts when you mount the woofer, and this box ships with one kit.

The numbers to respect

Set a 27 Hz subsonic filter, 24 dB per octave. Below tuning the vent stops loading the cone; with the filter in place the cone reaches 10.1 mm of its 23.5 mm at 1500 W.

Enclosure Specifications

Series	Proline X Professional
Driver-Specific Fitment	Skar Audio EVL-15 D2/D4 (Dual 2 Ohm or Dual 4 Ohm)
Enclosure Type	Ported \| Front-Firing Standard Box
External Width	36.00 Inches
External Height	18.00 Inches
External Depth	14.50 Inches
Internal Volume (Gross)	3.79 Cubic Feet
Internal Volume (Net After Displacement)	2.30 Cubic Feet
Port Type	Vertical Slot Beside The Woofer \| Front Exit \| One 90 Degree Bend Along The Back Wall
Port Geometry	3.00 x 16.50 Inches, 49.5 Square Inches, 37.71 Inches Of Path
Port Area	49.5 Square Inches
Port Tuning (Fb)	34.5 Hz
Port Mouth	1/2 In Roundover On All Four Edges, 70.0 Square Inches At The Face
Port Air Velocity	17.3 m/s In The Channel, 12.2 m/s At The Mouth, At 1500 W (17.0 m/s Chuff Threshold)
Design Power Basis	1500 W RMS (1.2 x The Driver Rating) For Port Velocity And Excursion
Predicted F3	30.7 Hz (Anechoic)
Passband Ripple	2.43 dB (Anechoic)
Subsonic Filter	27 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs	35.00 Hz
Driver Qts	0.630
Driver Qes / Qms	0.730 / 4.600
Driver Vas	46.000 Liters / 1.624 Cubic Feet
Driver Sd	779.3 Square Centimeters
Driver Mms	386.60 g
Driver BL	21.00
Driver Xmax	24mm (One-Way)
Driver Displacement	0.20 Cubic Feet (Published by Skar Audio)
Driver Sensitivity	86.2 dB
Driver Power Handling	1250 Watts RMS
Driver Overall Diameter	15.500 Inches (Skar Audio Spec)
Mounting Depth Required	8.540 Inches (Skar Audio Spec)
Cutout Diameter	14.000 Inches (Skar Audio Spec)
Flush Mount Recess	16.500 Inches In The Outer Layer
Material	Langboard Elite 3/4" MDF
Construction	ShopSabre CNC / Two Windowed Braces Front To Back Either Side Of The Woofer
Joinery	Dado Joinery (CNC-Cut), Flat Panels
Front Baffle Construction	Three 3/4" MDF layers, 2.25" total \| Woofer Flush-Mounted In The Outer Layer
Baffle Layers	3
Acrylic	Glossy Black Skar Audio Logo Insert, Outer Layer, Standard
Mounting Hardware	Threaded Insert Kit Included: 8-12 Inserts, Drill Bit, 2.5 In Allen-Head Screws, Allen Key, Gasket Tape
Voice Coil Configuration	Dual 2 Ohm
Terminal Cup	Proline X ABS/Carbon Fiber Composite \| Back Panel, Terminal-Cup Side \| 12g OFC Pre-Wired
Damping	None - Ships Dry. Polyfill Detunes A Ported Enclosure
Recommended Power	875-1250 Watts RMS (Skar Audio Rated: 1250W RMS)
Carpet Finish	Plush Black
Shipping Weight	76 lb
Shipping	UPS Ground Parcel, Included In The 48 States
Bundle Options	Enclosure Only (Bring Your Own Skar Audio EVL-15)
Warranty	2-Year Limited (Enclosure)
Manufactured	Tullahoma, Tennessee, USA

Performance Graphs

Net airspace

2.30

cu ft

Tuning

34.5

Hz · Fb

Half power

30.7

Hz · F3, anechoic

Xmax at

8063

W RMS · 27 Hz subsonic

With NO filter

1637

W RMS · unfiltered

Port

12.2

m/s at the mouth · 1500 W

01Is this driver right for a ported box?

Efficiency bandwidth product places the motor before anything else is decided.

EBP = Fs ÷ Qes = 47.9

Skar Audio EVL-15 D2 · EBP 47.9

Under 50 the raw number leans sealed. The Skar Audio EVL-15 D2 reads 47.9, so this is a ported build against the grain of its own EBP: it works because the alignment is tuned for in-car response rather than for an anechoic curve, and because the cabinet holds port area and volume the driver can actually use.

02What the box does to it

2.30 cu ft net against a 46.0 L Vas, vented at 34.5 Hz.

Fb = 34.5 Hz · F3 = 30.7 Hz · passband ripple 2.43 dB

Skar Audio EVL-15 D2 · Fb 34.5 Hz, F3 30.7 Hz

Anechoic, before any cabin gain, with the 27 Hz subsonic filter already applied. The vent takes over below 34 Hz and the cone stops doing the work there, which is what holds travel down at the bottom of the passband.

03Perceived Ported vs Sealed

This cabinet, 2.30 cu ft net vented at 34.5 Hz, against Skar Audio's recommended range (low end) sealed box, 3.00 cu ft.

Ported Fb 34.5 Hz · the 3.00 cu ft sealed box runs Qtc 0.78, Fc 43 Hz

Ported · this cabinet, 2.30 cu ft, Fb 34.5 HzSkar Audio's recommended sealed, 3.00 cu ft net, Qtc 0.78

Shaded blue is where the ported alignment is louder for the same power, orange where the sealed one is. The sealed curve is Skar Audio's recommended range (low end) sealed box, 3.00 cu ft, not this cabinet with the port blocked: two different boxes, because that is the choice a buyer actually has. Across 25 to 60 Hz the vent is worth 4.3 dB at its widest and 3.5 dB on average. This is the anechoic picture, which is not what you hear in a car.

04Real World Ported vs Sealed

The same two boxes with cabin gain applied, 45 Hz corner, 18 dB ceiling.

Flatness across 25–60 Hz: ported 2.2 dB spread, the 3.00 cu ft sealed box 2.4 dB

Ported, in-car · 2.2 dB spreadSkar Audio's recommended sealed, 3.00 cu ft net, in-car · 2.4 dB spread

Cabin gain lifts both boxes by the same amount, so the gap between them does not change: what changes is the shape each one ends up with. A car pressurises below roughly 45 Hz, which fills in the sealed box's shallower rolloff and over-drives it where the ported box is already flat. Across 25 to 60 Hz, the band kick and bass fundamentals occupy, this alignment holds 2.2 dB of spread against 2.4 dB for Skar Audio's recommended range (low end) sealed box, 3.00 cu ft. Flatter is the whole point of tuning this high. Note where the curves cross. Below about 23 Hz the sealed alignment becomes the louder of the two and stays louder all the way down, by up to 3.2 dB: a sealed box rolls off gently into the subsonic region where a vented one falls away steeply once it is below tuning and the vent stops contributing. If the content you are chasing lives below 23 Hz, a sealed alignment reaches further down than this one does. Cabin gain here is a house assumption, not a measurement of your vehicle.

05The 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 Skar's published 23.5 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.

P_Xmax = 8063 W with a 27 Hz subsonic · 1637 W with none → the filter is worth 4.9×

8063 W · subsonic at 27 Hz, 24 dB/oct1637 W · no subsonic filterXmax 23.5 mm one-way, published

Each trace touches the limit and no further, because each is drawn at the exact power that puts the cone on 23.5 mm. With a 27 Hz subsonic that takes 8063 W, reached first at 26 Hz. Take the filter away and the same cabinet reaches 23.5 mm on 1637 W — the filter is worth 4.9× the safe power. A vent unloads the cone below tuning, so there is nothing holding it once the box stops loading: on a sealed build a subsonic filter is an improvement, here it is required equipment. The unfiltered trace is still rising where this chart stops at 20 Hz, so treat 1637 W as a bound rather than a floor. Every wattage on this page is a MECHANICAL limit, not an electrical one. It is the power at which the cone runs out of linear travel in this cabinet, and nothing more. What the voice coil can dissipate as heat is a separate ceiling set by the driver, not by the box — Skar rate this one at 1250 W RMS, and that is the number that binds first here: heat stops you before travel does, so treat 1250 W as the ceiling and the travel figures above as headroom. Final wired impedance, amplifier output and how long you hold the level are all electrical questions this graph does not answer.

Woofer Details

The EVL-15 is the 15 inch in Skar Audio's EVL line: a competition grade pressed paper cone on a stitched high roll foam surround, a 3.00 in voice coil wound in four layers of Skar's black coated copper (CCAW), and a double slug magnet 7.10 in diameter, rated 1250 W RMS by Skar. Skar publishes a full Thiele-Small table for it on its product page, and no displacement, bolt circle or warranty term for the driver on that page. This enclosure is cut for 8.54 in of mounting depth and a 14.00 in cutout, taken from Skar Audio's published figures rather than measured off a sample. Where a rating below carries no reference condition, that is because the maker does not state one, and it is left as they print it.

Driver	Skar Audio EVL-15
Coil Options	Dual 2 Ohm or Dual 4 Ohm
Voice Coil Diameter	3.00 in
Coil Wire	Black Coated Copper (CCAW), 4 layer
Cone	Competition Grade Pressed Paper Cone
Surround	Stitched High Roll Foam Surround
Motor	Double slug magnet, 7.10 in diameter
Power, RMS	1250 W
Power, Peak	2500 W
Sensitivity	86.2 dB, reference condition not stated by Skar Audio
Mounting Depth	8.54 in
Cutout Diameter	14.00 in

Materials

Material

Built From a Spec Sheet, Not a Sales Sheet

Every Proline X Professional 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.

Specifications

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

Internal Bond

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.

Stiffness

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.

Screw Holding

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 Professional Series enclosure is not going anywhere.

Sourcing

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.