Professional Series · Datasheet

Professional Series Ported 12" Enclosure DD Audio 9512L ESP · Single 12" Ported enclosure

Net volume
3.73 Cubic Feet
Tuning
35.5 Hz
Max mounting depth
9.750 Inches (DD Audio Spec)
Cutout
12.188 Inches (DD Audio Spec)
External dimensions
32.00 Inches W × 16.00 Inches H × 26.50 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: 3.73 cu ft net vented at 35.5 Hz. F3 28.6 Hz anechoic, 5.39 dB passband ripple
  • Driver: DD Audio 9512L ESP D1 or D2, 2500 W RMS, 32.0 mm Xmax, 37.68 Hz Fs
  • Build: Front-firing standard box, 2.25" three-layer baffle with the woofer flush-mounted in the outer layer, DD Audio logo acrylic, dado joinery, 87.0 sq in front slot port beside the woofer with one bend along the back wall, port and excursion gated at 3000 W
  • Cabinet: 32.00" W x 16.00" H x 26.50" D, 76 lb, threaded insert kit included

Spec of record

Technical specifications

SeriesProline X Professional
Driver-Specific FitmentDD Audio 9512L ESP D1 or D2
Enclosure TypePorted | Front-Firing Standard Box
External Width32.00 Inches
External Height16.00 Inches
External Depth26.50 Inches
Internal Volume (Gross)6.01 Cubic Feet
Internal Volume (Net After Displacement)3.73 Cubic Feet
Port TypeVertical Slot Beside The Woofer | Front Exit | One 90 Degree Bend Along The Back Wall
Port Geometry6.00 x 14.50 Inches, 87.0 Square Inches, 36.65 Inches Of Path
Port Area87.0 Square Inches
Port Tuning (Fb)35.5 Hz
Port Mouth1/2 In Roundover On All Four Edges, 108.5 Square Inches At The Face
Port Air Velocity21.1 m/s In The Channel, 16.9 m/s At The Mouth, At 3000 W (17.0 m/s Chuff Threshold)
Design Power Basis3000 W RMS (1.2 x The Driver Rating) For Port Velocity And Excursion
Predicted F328.6 Hz (Anechoic)
Passband Ripple5.39 dB (Anechoic)
Subsonic Filter28 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs37.68 Hz
Driver Qts0.662
Driver Qes / Qms0.732 / 6.901
Driver Vas26.310 Liters / 0.929 Cubic Feet
Driver Sd613.1 Square Centimeters
Driver Xmax32mm (One-Way)
Driver Displacement0.29 Cubic Feet (Published by DD Audio)
Driver Power Handling2500 Watts RMS
Driver Overall Diameter13.375 Inches (DD Audio Spec)
Mounting Depth Required9.750 Inches (DD Audio Spec)
Cutout Diameter12.188 Inches (DD Audio Spec)
Flush Mount Recess14.375 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 DD 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
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 Power1750-2500 Watts RMS (DD Audio Rated: 2500W RMS)
Carpet FinishPlush Black
Weight76 lb
ShippingUPS Ground Parcel, Included In The 48 States
Bundle OptionsEnclosure Only (Bring Your Own DD Audio 9512L ESP)
Warranty2-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA

Modelled response

Performance in this enclosure

Net airspace
3.73
cu ft
Tuning
35.5
Hz · Fb
Half power
28.6
Hz · F3, anechoic
Xmax at
10690
W RMS · 28 Hz subsonic
With NO filter
3623
W RMS · unfiltered
Port
16.9
m/s at the mouth · 3000 W

01Is this driver right for a ported box?

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

EBP = Fs ÷ Qes = 51.5
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 EBP 51.5
DD Audio 9512L ESP · EBP 51.5
Between 50 and 100 a driver takes either load, and the choice becomes one of priorities rather than of physics. The DD Audio 9512L ESP reads 51.5. 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

3.73 cu ft net against a 26.3 L Vas, vented at 35.5 Hz.

Fb = 35.5 Hz  ·  F3 = 28.6 Hz  ·  passband ripple 5.39 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 35.5
DD Audio 9512L ESP · Fb 35.5 Hz, F3 28.6 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.

03Ported vs Sealed

No sealed comparison is shown for this driver.

A ported-versus-sealed chart is only worth reading against a sealed box someone would actually build: the one we make for the driver, or the one its maker recommends. Neither exists for the DD Audio 9512L ESP — we do not build a sealed enclosure for it and DD publish no sealed volume for it — so rather than compare this cabinet against itself stuffed and sealed, a box no one would build, the comparison is left out.

04The 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 DD's published 32.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.

PXmax = 10690 W with a 28 Hz subsonic  ·  3623 W with none  →  the filter is worth 3.0×
20 30 50 70 100 150 200 0 8 16 24 32 40 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 32.0 mm 10690 W reaches Xmax here
10690 W · subsonic at 28 Hz, 24 dB/oct3623 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 10690 W, reached first at 29 Hz. Take the filter away and the same cabinet reaches 32.0 mm on 3623 W — the filter is worth 3.0× 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 3623 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 — DD rate this one at 2500 W RMS, and that is the number that binds first here: heat stops you before travel does, so treat 2500 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 the 9512L ESP's own Fs, Qts, Qes, Qms and Vas; the Qts identity checks out cleanly, and there is no factory vented recommendation to compare against because DD doesn't publish one for this driver.

The port mouth runs 16.9 meters a second at the 1.2 times power gate, 3000 watts against the coil's own 2500 watt rating, and that is close enough to the chuff point that I would call this a marginal build. Run it at the rated power and it stays clean; push well past that and the port will let you know before the motor does.

DD does not publish a Bl or an Sd for the 9512L ESP. The piston area behind this box is derived from DD's own published piston diameter, and there is no motor force factor on their spec sheet to check the excursion math against.

DD Audio publishes no mounting hole locations for the 9512L ESP, so I cannot press the threaded inserts into the baffle before it ships. The insert kit ships in the box instead: set the inserts where the 9512L ESP's own bolt holes fall when you mount the driver.

Wire to the amplifier's rated impedance.

DD sells this one in D1 and D2, and publishes a single set of parameters for both, so the box does not change with the coil. Wire the D1 2 ohms in series or 0.5 ohm in parallel. Wire the D2 4 ohms in series or 1 ohm in parallel. There is no published DC resistance, so trust the label on the coil in front of you.

DD sells this one in D1 and D2, and publishes a single set of parameters for both, so the box does not change with the coil. Wire the D1 2 ohms in series or 0.5 ohm in parallel. Wire the D2 4 ohms in series or 1 ohm in parallel. There is no published DC resistance, so trust the label on the coil in front of you.

DD Audio publishes no mounting hole locations for the 9512L ESP, 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 9512L ESP: the calmest port that fits that envelope goes noisy at about 794 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 30 Hz.

Before you order

Questions

Why is this enclosure tuned to 35.5 Hz?

DD publishes a Qts of 0.662 for the 9512L ESP, and computing it from their own Qes of 0.732 and Qms of 6.901 reproduces that figure, so the driver's own numbers agree with each other. DD publish no vented recommendation for the 9512L ESP, so the 3.726 cubic foot net airspace and 35.5 Hz tuning come from our own solver working Fs, Qts and Vas against the coil's 2500 W rating. At 3000 W, 1.2 times that rating, the port mouth runs 16.9 m/s, close to the point where a slot starts to chuff, leaving almost no headroom in that number. 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 9512L ESP did not clear the port gate there. The calmest wedge port that fits that envelope is 19.9 square inches at 22.5 by 12.25 by 17.89 inches, and its mouth runs 30.2 metres per second at 2500 W against the 17 metres per second line where a port starts to chuff. That port would stay clean to about 794 W. The slot on this box reaches 87.0 square inches and holds the mouth at 16.9 metres per second at 3000 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 DD Audio logo acrylic, and a port and excursion budget checked at 3000 W. It carries a 2 year warranty against 1.

Threaded inserts or a kit?

DD Audio does not publish the mounting hole locations for the 9512L ESP, 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 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 DD Audio 9512L ESP at 53 percent of its usable travel at 3000 W.

Would a sealed box be better for me?

Not one we can show you. We do not build a sealed enclosure for the DD Audio 9512L ESP and DD Audio publish no sealed volume for it, so the Performance Graphs tab carries no ported-versus-sealed chart: the only sealed box left to plot would be this cabinet stuffed and sealed, which nobody would build, and a comparison against it would tell you nothing you could buy. What a vented box gives up is the region below tuning, where the cone unloads and the 28 Hz subsonic filter takes over; around 35.5 Hz the vent carries the load and cone travel drops to its minimum, which no sealed alignment can do.

How does the front port work?

It is a vertical slot beside the woofer, the full height of the cavity, 6.00 inches wide and 87.0 square inches. It runs 16.75 inches to the back wall and turns once along it for 10.15 inches; the fold costs about 1.5 Hz and the port is cut for it. The channel runs at 21.1 metres per second at 3000 W, 26 percent of its turbulence limit, and the mouth edges carry a 1/2 inch roundover so the air leaves the face at 16.9 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?

76 lb, 32.00" W x 16.00" H x 26.50" 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 7.85 cubic feet outside. Delivery to the 48 states is inside the price; it ships as a 76 lb parcel and checkout adds nothing. Do not add polyfill; it ships dry on purpose.

Is the 9512L ESP included?

No. This is an enclosure only, cut for the DD Audio 9512L ESP specifically: the 12.188 inch cutout, the 9.750 inch mounting depth allowance and the 3.73 cubic foot alignment all come from DD Audio's published parameters. It fits both coil versions; the alignment published here is the D1 or D2. Bring your own driver.

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