Professional Series · Datasheet

Professional Series Ported 10" Enclosure Sundown Audio U-Series v.1 10 · Single 10" Ported enclosure

Net volume
1.98 Cubic Feet
Tuning
33.5 Hz
Max mounting depth
7.007 Inches (Sundown Audio Spec)
Cutout
9.170 Inches (Sundown Audio Spec)
External dimensions
30.00 Inches W × 14.00 Inches H × 18.00 Inches D
Front baffle
Three 3/4" MDF layers, 2.25" total | Woofer Flush-Mounted In The Outer Layer
Buy at Audio IntensityFactory-direct, ships from Tullahoma
  • 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, 57 lb, threaded insert kit included

Spec of record

Technical 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
Weight57 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

Modelled response

Performance in this enclosure

Net airspace
1.98
cu ft
Tuning
33.5
Hz · Fb
Half power
28.9
Hz · F3, anechoic
Xmax at
8756
W RMS · 26 Hz subsonic
With NO filter
3036
W RMS · unfiltered
Port
16.6
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 = 105.4
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 EBP 105.4
Sundown Audio U-Series v.1 10 D4 · EBP 105.4
Above 100 the motor is asking for a vent. The Sundown Audio U-Series v.1 10 D4 reads 105.4, so a ported load is the alignment it was designed around, not a compromise applied to it.

02What the box does to it

1.98 cu ft net against a 11.5 L Vas, vented at 33.5 Hz.

Fb = 33.5 Hz  ·  F3 = 28.9 Hz  ·  passband ripple 3.77 dB
20 30 50 70 100 150 200 +16 +12 +8 +4 0 −4 −8 −12 −16 −20 −24 −28 FREQUENCY · Hz LEVEL · dB −3 dB Fb 33.5
Sundown Audio U-Series v.1 10 D4 · Fb 33.5 Hz, F3 28.9 Hz
Anechoic, before any cabin gain, with the 26 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, 1.98 cu ft net vented at 33.5 Hz, against Sundown Audio's recommended sealed box, 0.50 cu ft.

Ported Fb 33.5 Hz  ·  the 0.50 cu ft sealed box runs Qtc 0.47, Fc 55 Hz
20 30 50 70 100 150 200 +16 +12 +8 +4 0 −4 −8 −12 −16 −20 −24 −28 FREQUENCY · Hz LEVEL · dB +13.2 dB at 34 Hz
Ported · this cabinet, 1.98 cu ft, Fb 33.5 HzSundown Audio's recommended sealed, 0.50 cu ft net, Qtc 0.47
Shaded blue is where the ported alignment is louder for the same power, orange where the sealed one is. The sealed curve is Sundown Audio's recommended sealed box, 0.50 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 13.2 dB at its widest and 7.5 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 9.8 dB spread, the 0.50 cu ft sealed box 2.9 dB
20 30 50 70 100 150 200 +16 +12 +8 +4 0 −4 −8 −12 −16 −20 −24 −28 FREQUENCY · Hz LEVEL · dB +13.2 dB at 34 Hz
Ported, in-car · 9.8 dB spreadSundown Audio's recommended sealed, 0.50 cu ft net, in-car · 2.9 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 9.8 dB of spread against 2.9 dB for Sundown Audio's recommended sealed box, 0.50 cu ft. The sealed curve is flatter on paper; the ported one trades that for output. Note where the curves cross. Below about 22 Hz the sealed alignment becomes the louder of the two and stays louder all the way down, by up to 2.9 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 22 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 Sundown's published 30.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.

PXmax = 8756 W with a 26 Hz subsonic  ·  3036 W with none  →  the filter is worth 2.9×
20 30 50 70 100 150 200 0 8 16 24 32 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 30.0 mm 8756 W reaches Xmax here
8756 W · subsonic at 26 Hz, 24 dB/oct3036 W · no subsonic filterXmax 30.0 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 30.0 mm. With a 26 Hz subsonic that takes 8756 W, reached first at 27 Hz. Take the filter away and the same cabinet reaches 30.0 mm on 3036 W — the filter is worth 2.9× 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 3036 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 — Sundown 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.

From the shop floor

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.

Before you order

Questions

Why is this enclosure tuned to 33.5 Hz?

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. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz, and this tuning is where that sum comes out flattest across 25 to 60 Hz.

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

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. An under-ported box does not fail quietly. Air speed at the mouth rises with power; past the chuff line the flow turns turbulent and the port is audible on every note. The turbulence also chokes the port, so the box behaves as if it were tuned higher than it is, loses output near tuning, and lets the cone travel further below tuning than the design allows. This chassis is a full-size front-firing box on a 2.25 inch baffle built from three 3/4 inch layers with the woofer flush-mounted in the outer layer, a Sundown Audio logo acrylic, and a port and excursion budget checked at 1500 W. It carries a 2 year warranty against 1.

Threaded inserts or a kit?

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. A dual cabinet ships two kits.

Do I need a subsonic filter?

Yes, at 26 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 Sundown Audio U-Series v.1 10 at 41 percent of its usable travel at 1500 W.

Would a sealed box be better for me?

Below about 22 Hz, yes. The maker's recommended sealed box is louder down there by up to 2.9 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, 1.98 cubic feet vented at 33.5 Hz, against Sundown Audio's recommended sealed box, 0.50 cu ft, so you can see exactly where they cross.

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 37.5 square inches. It runs 11.25 inches to the back wall and turns once along it for 17.53 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 23.9 metres per second at 1500 W, 50 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 16.6 metres per second against the 17 metres per second threshold where a slot starts to chuff.

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

57 lb, 30.00" W x 14.00" H x 18.00" 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 4.38 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 57 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.

Is the U-Series v.1 10 included?

No. This is an enclosure only, cut for the Sundown Audio U-Series v.1 10 specifically: the 9.170 inch cutout, the 7.007 inch mounting depth allowance and the 1.98 cubic foot alignment all come from Sundown Audio's published parameters. It fits both coil versions; the alignment published here is the D4. Bring your own driver.

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