Proline X

Professional Series Ported 12" Enclosure | One Audio RSq3

Q: Do I need a subsonic filter?

Yes, at 28 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 One Audio RSq3 at 38 percent of its usable travel at 1800 W.

Q: Would a sealed box be better for me?

Below about 26 Hz, yes. The sealed wedge we build for it is louder down there by up to 5.5 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, 1.88 cubic feet vented at 36.0 Hz, against the 1.20 cu ft sealed wedge we build for this driver (PO 12-S W RSQ3), 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, 2.75 inches wide and 39.9 square inches. It runs 8.50 inches to the back wall and turns once along it for 19.36 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 24.6 metres per second at 1800 W, 46 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 16.8 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?

59 lb, 32.00" W x 16.00" H x 15.00" D external. It ships as a UPS parcel; the price includes shipping in the 48 states. Every Professional cabinet is priced the same way, by its size: this one is 4.44 cubic feet outside. Do not add polyfill; it ships dry on purpose.

Q: Is the RSq3 included?

No. This is an enclosure only, cut for the One Audio RSq3 specifically: the 1.88 cubic foot alignment comes from One Audio's published parameters, the 11.125 inch cutout from their dealer's figures, and the cabinet clears the RSq3's 9.00 inch mounting depth. It fits both coil versions; the alignment published here is the D2. Bring your own driver.

SKU: Pro 12-P RSQ3

QUICK SPECS

Alignment: 1.88 cu ft net vented at 36.0 Hz. F3 29.5 Hz anechoic, 5.43 dB passband ripple
Driver: One Audio RSq3 D2, 1500 W RMS, 32.0 mm Xmax, 25.80 Hz Fs
Build: Front-firing standard box, 2.25" three-layer baffle with the woofer flush-mounted in the outer layer, One Audio logo acrylic, dado joinery, 39.9 sq in front slot port beside the woofer with one bend along the back wall, port and excursion gated at 1800 W
Cabinet: 32.00" W x 16.00" H x 15.00" D, 59 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.

$ 502.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Complete Your System

Wavtech Link1500.1plus Amplifier - Compact 1500W Monoblock - Wavtech Amplifier for car audio systems

Wavtech Wavtech Link1500.1plus Amplifier - Compact 1500W Monoblock $ 699.99

Professional Series Ported 12" Enclosure | One Audio RSq3

$ 502.99

Enclosure Type Ported

External Dimensions 32.00" W x 16.00" H x 15.00" D

Net Volume 1.88 cu ft

Tuning Frequency 36.0 Hz

Port Area 39.9 Square Inches

Shipping Weight 59 lbs

INSTALLER'S TAKE

I built this box for one RSq3 on the full Professional chassis: three layers of baffle with the frame flush in the outer one, and a 2.75 inch slot beside the woofer that turns once along the back wall.

The RSq3 is a 1500 watt driver with 32 millimetres of travel and more than 320 grams moving, and the port is what limits it, not the cone. At 1800 watts, 1.2 times its rating, it uses 12.1 of its 32 millimetres and the slot mouth runs 16.8 metres per second, just under the 17 where a slot starts to chuff.

The D2 wires to 4 ohms in series or 1 in parallel. The D1 wires to 2 ohms or 0.5, and 0.5 needs an amplifier rated for it; most are not.

One Audio publishes no mounting hole locations for the RSq3, 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.

The Performance Optimized wedge is the smaller and cheaper box, and I try it first for every driver. I could not make its port keep up with the RSq3: the calmest port that fits that envelope goes noisy at about 834 watts, under what this coil is rated to take, so I did not sell you that box.

It ships dry. Do not add polyfill to a ported box. Set your subsonic filter at 28 Hz.

Product Details

Proline X Professional 12" Ported

One RSq3 in a full-size front-firing box, vented at 36 Hz on a three-layer baffle

1.88 cu ft net Tuned 36.0 Hz F3 29.5 Hz 2.25" three-layer baffle Cut for the RSq3 Built in Tennessee

1.88cu ft net

36.0Hz tuning

29.5Hz F3 anechoic

39.9sq in port area

Why this driver is vented at 36.0 Hz

The One Audio RSq3 carries 32 millimetres of travel, a 1500 watt rating and a 3 inch four-layer coil behind a 12.625 inch frame, and it takes 0.23 cubic feet out of any box it sits in. This cabinet gives it 1.88 cubic feet net, vented at 36 Hz through a 39.9 square inch slot beside the woofer, in a box 32 inches wide, 16 tall and 15 deep with the frame flush in a 2.25 inch baffle.

Threaded insert kit ships with this box. One Audio does not publish the mounting hole locations for the RSq3, 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.

One Audio publish a Qts of 0.45 for the RSq3 D2 and 0.47 for the D1, and both hold up: each column's Qes and Qms reproduce its own Qts, the two coils agree on Vas to within a percent, and Fs, Vas and Sd give back the moving mass they print. At 36 Hz, F3 is 29.5 Hz with 5.43 dB of passband ripple. The box is voiced for output: with cabin gain the low end rises well above the midbass, so expect deep, heavy bass rather than a flat in-car curve. At 1800 watts the cone uses 12.1 of its 32 millimetres and the port mouth runs 16.8 metres per second, under the 17 where a slot starts to chuff.

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.

One Audio logo acrylic

A glossy black acrylic insert with the One 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 1800 W

The 39.9 square inch slot beside the woofer is sized so the channel runs 24.6 metres per second and the mouth 16.8 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 8.50 inches along its wall and turns once along the back wall for another 19.36 inches, which is why a 36.0 Hz tuning fits a 15.00 inch deep box.

Why this is a Professional build

Every driver is run through the Performance Optimized wedge and down-fire before this chassis; the Professional box is where a driver lands when that smaller envelope, 30 inches wide and 18 inches deep with a triangular side port, cannot give it what it needs at its rated power. The RSq3 did not clear the port gate there. The calmest wedge port that fits that envelope is 24.7 square inches at 29.5 by 12.25 by 17.89 inches, and its mouth runs 22.8 metres per second at 1500 W against the 17 metres per second line where a port starts to chuff. That port would stay clean to about 834 W. The slot on this box reaches 39.9 square inches and holds the mouth at 16.8 metres per second at 1800 W.

What the price covers

Every Professional cabinet is priced the same way, by its size: this one is 4.44 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 59 lb parcel and checkout adds nothing.

The cabinet

32.00" W x 16.00" H x 15.00" 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 32 by 16 Professional envelope for a single 12, 15 inches deep. It ships as a parcel.

One Audio publish no fitment figures of their own. This cabinet is cut to an 11.125 inch cutout, a 12.625 inch frame and 0.23 cubic feet of driver displacement from One Audio's dealer figures, and it clears a 9.00 inch mounting depth with room to spare behind the motor. Set the subsonic filter at 28 Hz: below tuning the vent stops loading the cone. One Audio does not publish the mounting hole locations for the RSq3, 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 28 Hz subsonic filter, 24 dB per octave. Below tuning the vent stops loading the cone; with the filter in place the cone reaches 12.1 mm of its 32.0 mm at 1800 W.

Enclosure Specifications

Series	Proline X Professional
Driver-Specific Fitment	One Audio RSq3 D2 (the D1 also fits)
Enclosure Type	Ported \| Front-Firing Standard Box
External Width	32.00 Inches
External Height	16.00 Inches
External Depth	15.00 Inches
Internal Volume (Gross)	3.07 Cubic Feet
Internal Volume (Net After Displacement)	1.88 Cubic Feet
Port Type	Vertical Slot Beside The Woofer \| Front Exit \| One 90 Degree Bend Along The Back Wall
Port Geometry	2.75 x 14.50 Inches, 39.9 Square Inches, 34.36 Inches Of Path
Port Area	39.9 Square Inches
Port Tuning (Fb)	36.0 Hz
Port Mouth	1/2 In Roundover On All Four Edges, 58.1 Square Inches At The Face
Port Air Velocity	24.6 m/s In The Channel, 16.8 m/s At The Mouth, At 1800 W (17.0 m/s Chuff Threshold)
Design Power Basis	1800 W RMS (1.2 x The Driver Rating) For Port Velocity And Excursion
Predicted F3	29.5 Hz (Anechoic)
Passband Ripple	5.43 dB (Anechoic)
Subsonic Filter	28 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs	25.80 Hz
Driver Qts	0.450
Driver Qes / Qms	0.510 / 4.170
Driver Vas	36.780 Liters / 1.299 Cubic Feet
Driver Sd	480.0 Square Centimeters
Driver Mms	339.60 g
Driver BL	20.57
Driver Re	3.7 Ohm
Driver Xmax	32mm (One-Way)
Driver Displacement	0.23 Cubic Feet (Published by One Audio)
Driver Sensitivity	83.0 dB
Driver Power Handling	1500 Watts RMS
Driver Overall Diameter	12.625 Inches (One Audio Spec)
Mounting Depth Required	9.000 Inches (One Audio Spec)
Cutout Diameter	11.125 Inches (One Audio Spec)
Flush Mount Recess	13.625 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 One 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	D2
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	1050-1500 Watts RMS (One Audio Rated: 1500W RMS)
Carpet Finish	Plush Black
Shipping Weight	66 lb
Shipping	UPS Ground Parcel, Included In The 48 States
Bundle Options	Enclosure Only (Bring Your Own One Audio RSq3)
Warranty	2-Year Limited (Enclosure)
Manufactured	Tullahoma, Tennessee, USA

Performance Graphs

Net airspace

1.88

cu ft

Tuning

36.0

Hz · Fb

Half power

29.5

Hz · F3, anechoic

Xmax at

12506

W RMS · 28 Hz subsonic

With NO filter

2281

W RMS · unfiltered

Port

16.8

m/s at the mouth · 1800 W

01Is this driver right for a ported box?

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

EBP = Fs ÷ Qes = 50.6

One Audio RSq3 D2 · EBP 50.6

Between 50 and 100 a driver takes either load, and the choice becomes one of priorities rather than of physics. The One Audio RSq3 D2 reads 50.6. Ported buys output and low-end reach around tuning; sealed buys a shallower rolloff below it. This cabinet takes the first trade.

02What the box does to it

1.88 cu ft net against a 36.8 L Vas, vented at 36.0 Hz.

Fb = 36.0 Hz · F3 = 29.5 Hz · passband ripple 5.43 dB

One Audio RSq3 D2 · Fb 36.0 Hz, F3 29.5 Hz

Anechoic, before any cabin gain, with the 28 Hz subsonic filter already applied. The vent takes over below 36 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, 1.88 cu ft net vented at 36.0 Hz, against the 1.20 cu ft sealed wedge we build for this driver (PO 12-S W RSQ3).

Ported Fb 36.0 Hz · the 1.20 cu ft sealed box runs Qtc 0.65, Fc 37 Hz

Ported · this cabinet, 1.88 cu ft, Fb 36.0 HzSealed wedge we build, 1.20 cu ft, Qtc 0.65

Shaded blue is where the ported alignment is louder for the same power, orange where the sealed one is. The sealed curve is the 1.20 cu ft sealed wedge we build for this driver (PO 12-S W RSQ3), 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 8.5 dB at its widest and 4.9 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 6.9 dB spread, the 1.20 cu ft sealed box 4.2 dB

Ported, in-car · 6.9 dB spreadSealed wedge we build, 1.20 cu ft, in-car · 4.2 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 6.9 dB of spread against 4.2 dB for the 1.20 cu ft sealed wedge we build for this driver (PO 12-S W RSQ3). The sealed curve is flatter on paper; the ported one trades that for output. Note where the curves cross. Below about 26 Hz the sealed alignment becomes the louder of the two and stays louder all the way down, by up to 5.5 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 26 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 One's published 32.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.

P_Xmax = 12506 W with a 28 Hz subsonic · 2281 W with none → the filter is worth 5.5×

12506 W · subsonic at 28 Hz, 24 dB/oct2281 W · no subsonic filterXmax 32.0 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 32.0 mm. With a 28 Hz subsonic that takes 12506 W, reached first at 27 Hz. Take the filter away and the same cabinet reaches 32.0 mm on 2281 W — the filter is worth 5.5× 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 2281 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 — One rate this one at 1500 W RMS, and that is the number that binds first here: heat stops you before travel does, so treat 1500 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

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.