Performance Optimized · Datasheet

Performance Optimized Wedge Ported 12" Enclosure DD Audio SL712 · Single 12" Ported enclosure

Net volume
1.56 Cubic Feet
Tuning
36.5 Hz
Max mounting depth
5.500 Inches (DD Audio Spec)
Cutout
11.375 Inches (DD Audio Spec)
External dimensions
30.00 Inches W × 15.50 Inches H × 9.50 Inches / 15.14 Inches D
Front baffle
Vertical Baffle - Driver Fires Rearward Into The Trunk
Buy at Audio IntensityFactory-direct, ships from Tullahoma
  • Alignment: 1.56 cu ft net vented at 36.5 Hz. F3 31.2 Hz anechoic, 3.90 dB passband ripple
  • Driver: DD Audio SL712 D2 or D4, 1000 W RMS, 19.0 mm Xmax, 29.00 Hz Fs
  • Build: Rear-firing wedge, 20 degree rear rake, V-groove and dado joinery, triangular side-exit slot port with a 1/2" rounded mouth, double 1.5" baffle, side-mounted terminal cup
  • Cabinet: 30.00" W x 15.50" H x 15.14" D at base tapering to 9.50" D at top, 24.7 sq in port, ships dry

Spec of record

Technical specifications

SeriesProline X Performance Optimized Wedge
Driver-Specific FitmentDD Audio SL712 D2 or D4
Enclosure TypePorted | Rear-Firing Trunk Wedge
Baffle ConfigurationVertical Baffle - Driver Fires Rearward Into The Trunk
Wedge Angle20 Degrees On The Rear (Seat-Side) Panel
External Width30.00 Inches
External Height15.50 Inches
Top Depth9.50 Inches
Base Depth15.14 Inches
Internal Volume (Gross)2.08 Cubic Feet
Internal Volume (Net After Displacement)1.56 Cubic Feet
Port TypeTriangular Slot | Bottom-Rear Corner | Straight, No Bend | Side Exit
Port GeometryIsosceles, 7.25 Inch Legs, 24.7 Square Inches, 24.63 Inches Long, Side Mouth
Port Tuning (Fb)36.5 Hz
Port MouthTriangle Through Side A, 1/2 In Roundover On All Three Edges, 37.4 Square Inches At The Face
Port ThroatOpen Far End, 3.62 In Gap To Side B, 3/8 In Roundover On The Panel End
Port Air Velocity24.4 m/s In The Channel, 16.1 m/s At The Flared Mouth (17.0 m/s Chuff Threshold)
Predicted F331.2 Hz (Anechoic)
Passband Ripple3.90 dB (Anechoic)
Subsonic Filter29 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure
Driver Fs29.00 Hz
Driver Qts0.540
Driver Qes / Qms0.620 / 5.400
Driver Vas39.200 Liters / 1.384 Cubic Feet
Driver Sd532.4 Square Centimeters
Driver Xmax19mm (One-Way)
Driver Displacement0.07 Cubic Feet (Published by DD Audio)
Driver Power Handling1000 Watts RMS
Driver Overall Diameter12.375 Inches (DD Audio Spec)
Mounting Depth Required5.500 Inches (DD Audio Spec)
Cutout Diameter11.375 Inches (DD Audio Spec)
MaterialLangboard Elite 3/4" MDF
ConstructionShopSabre CNC / Two Windowed C Braces At The Third Points, Seated On The Port Panel
JoineryV-Groove and Dado (CNC-Cut)
Front Baffle ConstructionDouble-Layer 1.5" MDF | Cosmetic Front Layer Routed For The Acrylic Insert
Mounting HardwareThreaded Inserts At Every Mounting Location | Stainless Steel Machine Screws Included
Terminal CupProline X ABS/Carbon Fiber Composite | Side Mounted, Opposite The Port | 12g OFC Pre-Wired
DampingNone - Ships Dry. Polyfill Detunes A Ported Enclosure
Recommended Power700-1000 Watts RMS (DD Audio Rated: 1000W RMS)
Carpet FinishPlush Black
Weight52 lb
Bundle OptionsEnclosure Only (Bring Your Own DD Audio SL712)
Warranty1-Year Limited (Enclosure)
ManufacturedTullahoma, Tennessee, USA

Modelled response

Performance in this enclosure

Net airspace
1.56
cu ft
Tuning
36.5
Hz · Fb
Half power
31.2
Hz · F3, anechoic
Xmax at
5262
W RMS · 29 Hz subsonic
With NO filter
721
W RMS · unfiltered
Port
16.1
m/s at the mouth

01Is this driver right for a ported box?

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

EBP = Fs ÷ Qes = 46.8
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 EBP 46.8
DD Audio SL712 · EBP 46.8
Under 50 the raw number leans sealed. The DD Audio SL712 reads 46.8, 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

1.56 cu ft net against a 39.2 L Vas, vented at 36.5 Hz.

Fb = 36.5 Hz  ·  F3 = 31.2 Hz  ·  passband ripple 3.90 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 36.5
DD Audio SL712 · Fb 36.5 Hz, F3 31.2 Hz
Anechoic, before any cabin gain, with the 29 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 SL712 — 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 19.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.

PXmax = 5262 W with a 29 Hz subsonic  ·  721 W with none  →  the filter is worth 7.3×
20 30 50 70 100 150 200 0 4 8 12 16 20 24 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 19.0 mm 5262 W reaches Xmax here
5262 W · subsonic at 29 Hz, 24 dB/oct721 W · no subsonic filterXmax 19.0 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 19.0 mm. With a 29 Hz subsonic that takes 5262 W, reached first at 27 Hz. Take the filter away and the same cabinet reaches 19.0 mm on 721 W — the filter is worth 7.3× 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 721 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 1000 W RMS, and that is the number that binds first here: heat stops you before travel does, so treat 1000 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

The SL712 carries 39.20 litres of Vas on a 29.00 Hz motor, a 0.54 Qts with a 0.62 Qes and a 5.40 Qms behind it, a vented profile. I get it 1.555 cubic feet net at 36.5 Hz, and the model gives back a 31.2 Hz F3. DD does not publish a vented number of its own for this driver, so there is nothing to compare the curve against. The Sd behind this solve, 532.4 square centimetres, is not something DD publishes directly. I derive it from their own published piston diameter, pi times the radius squared, because DD does not print Sd, Mms, Cms, Re, or an Xmax basis for the SL712. Frame, cutout, mounting depth, and displacement are DD's own numbers and needed no derivation. This cabinet is a trunk-shaped wedge: the rear panel carries the 20 degree rake, the baffle the driver mounts to stays vertical, and the port is a triangular chamber cut into the side behind a 1.5 inch double baffle. DD publishes no bolt hole locations for this driver, so I am not pressing the threaded inserts before it ships. The insert kit rides loose in the box; set them at install once the driver is in hand. DD sells this one in D2 and D4, and publishes a single set of parameters for both, so the box does not change with the coil. Wire the D2 4 ohms in series or 1 ohm in parallel. Wire the D4 8 ohms in series or 2 ohms in parallel. There is no published DC resistance, so trust the label on the coil in front of you.

It ships dry. Do not add polyfill to a ported box. Set your subsonic filter at 31 Hz.

Before you order

Questions

Why is this enclosure tuned to 36.5 Hz?

A 0.54 Qts on 39.20 litres of Vas, backed by a Qes of 0.62 and a Qms of 5.40, is a motor built for a vented box, and 36.5 Hz brings the reach down to a 31.2 Hz F3. DD publishes no vented alignment of its own for the SL712, so this build is not weighed against a factory number. The 532.4 square centimetre Sd behind the solve is not a DD figure: DD publishes no Sd for this driver, so it comes from DD's own published piston diameter through Sd = pi times the radius squared. The rear panel carries the wedge's 20 degree rake for the trunk-shaped cabinet; the baffle stays vertical, the port is a triangular chamber run through the side, and the baffle itself is a 1.5 inch double layer. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz. In this cabinet that lands at 4.6 dB of in-car spread across 25 to 60 Hz.

Why the 20 degree wedge, and why rear-firing?

The raked face is the seat side. A factory rear seat back leans about 20 degrees off vertical, so the cabinet sits flat against it and uses floor a square box wastes. The baffle stays vertical and fires rearward into the trunk, which acts as the acoustic extension into the cabin. This one is 15.14 inches deep at the base and 9.50 at the top, 30.00 wide and 16 tall.

Do I need a subsonic filter?

Yes, at 29 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 SL712 at 44 percent of its usable travel at full rated power; without it there is no meaningful number to quote.

How much power can I run, and at what impedance?

DD Audio rate the SL712 at 1000 W RMS and that is the thermal ceiling. The Performance Graphs tab shows the mechanical limit, the power at which the cone reaches the end of its travel in this cabinet: here the cone sits at 44 percent of usable travel at the rating, so heat is what stops you, not travel. A D2 coil is 4 ohms in series or 1 ohm in parallel; run series unless the amplifier is rated for 1 ohm. A D4 is 8 series or 2 parallel.

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 SL712 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 29 Hz subsonic filter takes over; around 36.5 Hz the vent carries the load and cone travel drops to its minimum, which no sealed alignment can do.

How does the side port work?

It is a triangular slot in the bottom-rear corner: the floor and the raked back wall are two sides, one bevelled panel is the third. It runs across the cabinet, opens into the box through a 3.62 inch gap at the far end and exits through the side panel as the same triangle. Straight, no bend: 24.63 inches of path and 24.7 square inches of channel running at 24.4 metres per second, 54 percent of its turbulence limit. The three mouth edges are rounded over at 1/2 inch, so the opening at the face is 37.4 square inches and the air leaves it at 16.1 metres per second against the 17.0 threshold where a slot port starts to chuff; the panel's throat end is rounded at 3/8 inch for the same reason. The terminal cup is on the other side.

Does this enclosure ship with polyfill?

No, and do not add any. Every sealed Proline X enclosure ships with polyfill; a ported one must not, because damping changes the effective volume the port is tuned against. The port here is cut to 24.63 inches for 36.5 Hz. Stuff it and you move the tuning without shortening the port.

Is the SL712 included?

No. This is an enclosure only, cut for the DD Audio SL712 specifically: the 11.375 inch cutout, the 5.500 inch mounting depth allowance and the 1.56 cubic foot alignment all come from DD Audio's published parameters. It fits both coil versions; the alignment published here is the D2 or D4. Bring your own driver.

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