Pro 10-P U10 placeholder
Pro 10-P U10 placeholder

Proline X

Professional Series Ported 10" Enclosure | Sundown Audio U-Series v.1 10

SKU: Pro 10-P U10

QUICK SPECS
  • Alignment: 1.98 cu ft net vented at 33.5 Hz. F3 28.9 Hz anechoic, 3.77 dB passband ripple
  • Driver: Sundown Audio U-Series v.1 10 D4, 1500 W RMS, 30.0 mm Xmax, 41.10 Hz Fs
  • Build: Front-firing standard box, 2.25" three-layer baffle with the woofer flush-mounted in the outer layer, Sundown Audio logo acrylic, dado joinery, 37.5 sq in front slot port beside the woofer with one bend along the back wall, port and excursion gated at 1500 W
  • Cabinet: 30.00" W x 14.00" H x 18.00" D, 70 lb, threaded insert kit included
Shipping Icon
Shipping Included No freight charges at checkout on US orders. International orders are quoted live carrier rates at checkout.
USA Flag Rounded
Built in Tennessee CNC cut from 3/4" Langboard Elite MDF. V-groove and dado joinery.
Gear icon
Advanced Terminal Cup Built in-house. ABS/Carbon Fiber. Stainless steel hardware. Copper ring terminals.
$ 502.99
In Stock and Ready to Ship
Shop Pay Financing available. Choose Shop Pay Installments at checkout.
Pro 10-P U10 placeholder

Professional Series Ported 10" Enclosure | Sundown Audio U-Series v.1 10

Regular price $ 502.99
Sale price $ 502.99 Regular price
Unit price
Enclosure Type Ported
External Dimensions 30.00" W x 14.00" H x 18.00" D
Gross Volume 3.09 cu ft
Net Volume 1.98 cu ft
Tuning Frequency 33.5 Hz
Port Area 37.5 Square Inches
Weight 70 lbs
INSTALLER'S TAKE

I built this box on Sundown's own published numbers for the U-10, and the D4 and D2 versions of this driver share the same basket, so one cabinet and one listing covers both.

The port here is modeled clean past the coil's own 1500 watt rating, out to 1573 watts, but the margin is thin: the mouth runs at 16.6 meters per second on the D4 coil and 16.0 on the D2, both within a meter per second of where a slot starts to chuff.

Wire the D4 coil in series for 8 ohms or parallel for 2 ohms; wire the D2 coil in series for 4 ohms or parallel for 1 ohm. A parallel load under 1 ohm needs an amplifier rated for it.

Sundown Audio publishes no mounting hole locations for the U-Series v.1 10, 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 U-Series v.1 10: the calmest port that fits that envelope goes noisy at about 661 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 29 Hz.

Product Details
Enclosure Specifications
Woofer Details
Materials
Related Video
Product Details

Proline X Professional 10" Ported

A ported ten-inch box built to Sundown's own numbers for the U-Series v.1 10

1.98 cu ft net Tuned 33.5 Hz F3 28.9 Hz 2.25" three-layer baffle Cut for the U-Series v.1 10 Built in Tennessee
1.98cu ft net
33.5Hz tuning
28.9Hz F3 anechoic
37.5sq in port area

Why this driver is vented at 33.5 Hz

The Sundown Audio U-Series v.1 10 D4 carries a 10.94 inch frame and a 7.007 inch mounting depth, and this cabinet gives it 1.977 cubic feet net, vented at 33.5 Hz through a 37.5 square inch port beside the woofer on the front face. F3 lands at 28.9 Hz with 3.77 dB of passband ripple. The 30.0 by 14.0 by 18.0 inch enclosure carries a single 90 degree bend in the port, and the D2 version of this driver shares the same cabinet.

Threaded insert kit ships with this box. Sundown Audio does not publish the mounting hole locations for the U-Series v.1 10, so we cannot install the threaded inserts before it ships. The threaded insert kit comes in the box instead: 8 to 12 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; one kit serves one woofer.

The gate here is measured at the coil's rated power, 1500 W, and the port stays clean past that rating, modeled to 1573 W before mouth velocity becomes the limiting factor. That margin is thin: this port's mouth runs at 16.6 m/s on the D4 coil and 16.0 m/s on the D2, both within 1 m/s of the 17 m/s point where a slot starts to chuff. Ripple across the passband holds at 3.77 dB.

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.

Sundown Audio logo acrylic

A glossy black acrylic insert with the Sundown 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 37.5 square inch slot beside the woofer is sized so the channel runs 23.9 metres per second and the mouth 16.6 metres per second at the driver's rated power, under the 17 metres per second where a slot starts to chuff. The channel runs 11.25 inches along its wall and turns once along the back wall for another 17.53 inches, which is why a 33.5 Hz tuning fits a 18.00 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 U-Series v.1 10 did not clear the port gate there. The calmest wedge port that fits that envelope is 18.4 square inches at 25.5 by 10.75 by 15.66 inches, and its mouth runs 25.6 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 661 W. The slot on this box reaches 37.5 square inches and holds the mouth at 16.6 metres per second at 1500 W.

What the price covers

Every Professional cabinet is priced the same way, by its size: this one is 4.38 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 70 lb parcel and checkout adds nothing. The Performance Optimized 10 inch ported wedge is $369.99. The $133 difference is the larger box and the port this driver needs to run at its rating.

What Sundown Audio recommend

Sundown Audio publish a vented box for the U-Series v.1 10 at 1.00 cubic feet on a basis they do not state, tuned to 35.0 Hz. This cabinet holds 1.98 cubic feet net and tunes to 33.5 Hz. They call for a port area of 16 sq in. The extra air and the lower tuning move the low corner down, which costs a little output right at their tuning and gains it below.

The cabinet

30.00" W x 14.00" H x 18.00" 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. This is our single-ten ported envelope built around the U-10's own frame and motor depth. It ships as a parcel.

This cabinet's port mouth runs close to the chuff line on both coils it fits, 16.6 m/s on the D4 and 16.0 m/s on the D2, against a 17 m/s threshold. It is not over the line on either coil, but there is not much room before it would be at the power this build treats as clean. Push past the modeled 1573 W and the port itself, not the coil, is the first thing to be heard. Sundown Audio does not publish the mounting hole locations for the U-Series v.1 10, so we cannot install the threaded inserts before it ships. The threaded insert kit comes in the box instead: 8 to 12 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; one kit serves one woofer.

The numbers to respect

Set a 26 Hz subsonic filter, 24 dB per octave. Below tuning the vent stops loading the cone; with the filter in place the cone reaches 12.4 mm of its 30.0 mm at 1500 W.

Enclosure Specifications
SeriesProline X Professional
Driver-Specific FitmentSundown Audio U-Series v.1 10 D4 (D4)
Enclosure TypePorted | Front-Firing Standard Box
External Width30.00 Inches
External Height14.00 Inches
External Depth18.00 Inches
Internal Volume (Gross)3.09 Cubic Feet
Internal Volume (Net After Displacement)1.98 Cubic Feet
Port TypeVertical Slot Beside The Woofer | Front Exit | One 90 Degree Bend Along The Back Wall
Port Geometry3.00 x 12.50 Inches, 37.5 Square Inches, 35.53 Inches Of Path
Port Area37.5 Square Inches
Port Tuning (Fb)33.5 Hz
Port Mouth1/2 In Roundover On All Four Edges, 54.0 Square Inches At The Face
Port Air Velocity23.9 m/s In The Channel, 16.6 m/s At The Mouth, At 1500 W (17.0 m/s Chuff Threshold)
Design Power Basis1500 W RMS (1.2 x The Driver Rating) For Port Velocity And Excursion
Predicted F328.9 Hz (Anechoic)
Passband Ripple3.77 dB (Anechoic)
Subsonic Filter26 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs41.10 Hz
Driver Qts0.350
Driver Qes / Qms0.390 / 3.210
Driver Vas11.500 Liters / 0.406 Cubic Feet
Driver Sd340.1 Square Centimeters
Driver Mms219.70 g
Driver BL29.70
Driver Re6.1 Ohm
Driver Xmax30mm (One-Way)
Driver Displacement0.18 Cubic Feet (Published by Sundown Audio)
Driver Sensitivity84.9 dB
Driver Power Handling1500 Watts RMS
Driver Overall Diameter10.940 Inches (Sundown Audio Spec)
Mounting Depth Required7.007 Inches (Sundown Audio Spec)
Cutout Diameter9.170 Inches (Sundown Audio Spec)
Flush Mount Recess11.875 Inches In The Outer Layer
MaterialLangboard Elite 3/4" MDF
ConstructionShopSabre CNC / Two Windowed Braces Front To Back Either Side Of The Woofer
JoineryDado Joinery (CNC-Cut), Flat Panels
Front Baffle ConstructionThree 3/4" MDF layers, 2.25" total | Woofer Flush-Mounted In The Outer Layer
Baffle Layers3
AcrylicGlossy Black Sundown Audio Logo Insert, Outer Layer, Standard
Mounting HardwareThreaded Insert Kit Included: 8-12 Inserts, Drill Bit, 2.5 In Allen-Head Screws, Allen Key, Gasket Tape
Voice Coil ConfigurationD4
Terminal CupProline X ABS/Carbon Fiber Composite | Back Panel, Terminal-Cup Side | 12g OFC Pre-Wired
DampingNone - Ships Dry. Polyfill Detunes A Ported Enclosure
Recommended Power1050-1500 Watts RMS (Sundown Audio Rated: 1500W RMS)
Carpet FinishPlush Black
Weight70 lb
ShippingUPS Ground Parcel, Included In The 48 States
Bundle OptionsEnclosure Only (Bring Your Own Sundown Audio U-Series v.1 10)
Warranty2-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA
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.

Related Video

Featured Video

No video available

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

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

Handcrafted in USA

Hand-assembled at our facility in Tullahoma, TN. Every enclosure is inspected before it ships.

Tuned to the Build

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.

Frequently Asked Questions

Why is this enclosure tuned to 33.5 Hz?

Why is this a Professional build and not a Performance Optimized box?

Threaded inserts or a kit?

Do I need a subsonic filter?

Would a sealed box be better for me?

How does the front port work?

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

Is the U-Series v.1 10 included?

Related Articles

Subwoofer Port Area Calculator: A Complete Guide to Accurate Tuning - Audio Intensity

Subwoofer Port Area Calculator: A Complete Guide to Accur...

A free, on-page calculator that turns your net box volume and tuning frequency into exact port a...

Read Article →
How to Use a Subwoofer Box Calculator for Perfect Enclosure Design - Audio Intensity

What Size Box Does My Subwoofer Need? Using a Box Volume ...

A free dual-mode box calculator. Enter external dimensions and panel thickness for gross and net...

Read Article →
Ford Maverick Sub: The Ultimate Audio Upgrade - Audio Intensity

Ford Maverick Sub: The Ultimate Audio Upgrade

Upgrading your Ford Maverick subwoofer can significantly enhance your car audio experience. Diffe...

Read Article →
12 Inch Speaker Box for Car: Sizing and Box Design Guide

12 Inch Speaker Box for Car: Sizing and Box Design Guide

Sealed or ported, how much airspace a 12 actually needs, and what goes wrong when the volume is ...

Read Article →