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Proline X PO 12-S W SL712 sealed wedge, front baffle with gloss black insert and pre-wired leads, 23.2 by 15 inches.
Proline X PO 12-S W SL712 sealed wedge, side profile with recessed terminal cup, 12.4 inch base, 15 inches tall.

Performance Optimized · Datasheet

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

Net volume
1.00 cu ft
Max mounting depth
6.25 in available, 5.500 in required
Cutout
11.375 in
External dimensions
23.24 in W × 15 in at the seat face H × 12.40 in at the base D
Front baffle
1.5 in, double baffle
Buy at Audio IntensityFactory-direct, ships from Tullahoma
DD Audio SL712Buy at Audio Intensity
  • Best For: DD Audio SL712 Trunk-Fit Builds
  • Net Volume: 1.00 cu ft (1.08 cu ft Gross)
  • Alignment: Qtc 0.834, fc 44.8 Hz, F3 39.0 Hz
  • Driver Match: DD Audio SL712 (D2 or D4)
  • Construction: Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | Threaded Insert Kit included

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge
Compatible DriverDD Audio SL712, D2 or D4, quantity 1. Direct fit
ConfigurationSingle 12 inch, single chamber sealed wedge
Mounting PositionTrunk or cargo area, tall face against the rear seat back
Firing DirectionRearward into the trunk. Not a down fire design, no feet included
External Width23.24 in
External Height15 in at the seat face
External Depth12.40 in at the base, tapering to 6.94 in at the top
Internal Volume, Gross1.08 cu ft
Internal Volume, Net Acoustic1.00 cu ft
AlignmentQtc 0.834, fc 44.8 Hz, F3 39.0 Hz anechoic
Driver Cutout11.375 in
Driver Mounting Depth6.25 in available, 5.500 in required
Frame Outer Diameter12.375 in, as published by DD Audio
Driver Displacement0.070 cu ft each, as published by DD Audio
Cone Area (derived)532.4 cm2, from DD's published piston diameter; DD publish no Sd
Power Handling1000 watts RMS per driver
ImpedanceD2: 4 ohms in series or 1 ohm in parallel; D4: 8 ohms in series or 2 ohms in parallel
Xmax19 mm one way
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery
Panel Thickness0.75 in
Front Baffle1.5 in, double baffle
Internal BracingInternal brace
Driver MountingThreaded insert kit included, NOT pre-installed: DD publish no mounting hole locations
Terminal CupsOne Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC
DampingLight polyfill wall lining, does not alter acoustic volume
CarpetPlush black
Weight31.6 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.00
cu ft
System Qtc
0.83
sealed
Half power
39.0
Hz · F3
Xmax at
1103
W RMS · no filter
With 25 Hz subsonic
1311
W RMS · +19%
Amplifier
1000
W RMS recommended
This enclosure holds 1.00 cu ft net . In it the DD Audio SL712 runs a system Qtc of 0.83 with half power at 39.0 Hz, and the cone reaches its 19.0 mm travel limit at 1103 W, above the driver’s 1000 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 1311 W — +208 W, or 19 percent more power for the same 19.0 mm of travel.

01Is it a sealed driver?

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 SL712, D2 or D4 (DD publish one shared table) 46.8
SL712, D2 or D4 (DD publish one shared table) · EBP 46.8
EBP under 50 means a motor that wants a sealed load. The SL712 sits at 46.8, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

1.00 cu ft against a 39.2 L Vas.

α = Vas ÷ Vb = 1.38  ·  Fc = Fs√(α+1) = 45 Hz  ·  Qtc = 0.83
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
SL712, D2 or D4 (DD publish one shared table) · Qtc 0.83, Fc 45 Hz, F3 39.0 Hz
The box lifts resonance from 29.0 Hz free-air to 45 Hz and half power lands at 39.0 Hz, anechoic, before any cabin gain. Figures are DD Audio’s own published table for the SL712, which covers the D2 and D4 alike. DD publish no cone area; the 532.4 square centimetre figure is derived from their published piston diameter. DD’s sealed range for this driver is 0.70 to 1.50 cubic feet, Qtc 0.93 to 0.75; this cabinet is 1.00 cubic feet, inside that range. At Qtc 0.83 it is punchy, with a mild rise near resonance.

03The 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 19.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 1103 W unfiltered  →  1311 W with a 25 Hz subsonic
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 1103 W reaches Xmax here
SL712, D2 or D4 (DD publish one shared table) · 1103 W, no filterSL712, D2 or D4 (DD publish one shared table) · 1311 W with subsonic at 25 Hz, 24 dB/octXmax 19.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 19.0 mm. Unfiltered that is 1103 W, reached first at 24 Hz. It sits above the 1000 W the driver can take thermally, so the voice coil gives up before the suspension does. The dashed traces are the same driver behind a subsonic filter at 25 Hz, 24 dB/oct: stopping the cone wasting travel below the passband lets it take 1311 W before hitting the same 19.0 mm. That is 19 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs29.00Hzfree-air resonance
Qts0.540SL712, D2 or D4 (DD publish one shared table)
Vas39.20Lequivalent compliance
Sd532.4cm²effective piston area
Xmax19mmone-way, as DD publish it, with no stated measurement basis
Pe1000Wcontinuous RMS
SPL83.7dB1 W / 1 m, derived from T/S

Driver parameters as published by DD Audio published SL712 specifications (one table for D2 and D4). Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

1.00 cubic feet net. DD's own sealed range for the SL712 is 0.7 to 1.5 cubic feet, Qtc 0.93 to 0.75, and a maximally flat box would take 1.94 cubic feet. This cabinet sits inside that range, toward its smaller end, where the SL712 plays with more punch and stays inside Xmax at its full rated power. In 1.00 cubic feet the SL712 lands at Qtc 0.834, punchy, with a mild rise near resonance and extra midbass, with system resonance at 44.8 Hz. Half power lands at 39.0 Hz anechoic, before any cabin gain.

DD publishes no Sd for any of its drivers. The 532.4 square centimetre figure behind this alignment is derived from DD's own published piston diameter, which they define as measured halfway across the surround, the convention Sd itself is defined from. DD publishes no Mms, Cms or DC resistance either.

DD publishes no mounting hole locations, so the inserts are not in the baffle when the box arrives. The insert kit is in the box: set them where the woofer's own holes fall, with the drill bit and screws in the kit, and lay the gasket tape before the woofer goes down.

DD sells the SL712 in D2 and D4. The D2 is two 2 ohm coils, 4 ohms in series or 1 ohm in parallel; the D4 is two 4 ohm coils, 8 ohms in series or 2 ohms in parallel. DD publishes one set of Thiele-Small parameters for the model rather than a set per coil, so this cabinet is the same either way. A parallel load at or under 1 ohm needs an amplifier rated for it.

Measure the base depth. This cabinet is 12.40 inches deep at the trunk floor, 6.94 at the top, and 23.24 wide.

Before you order

Questions

Will this enclosure fit both coil versions of the SL712?

Yes. DD sells the SL712 in D2 and D4 and publishes one set of Thiele-Small parameters for the model rather than a set per coil, so the cabinet is the same either way. The cutout is 11.375 in and the mounting depth allowance is 6.25 in.

Why 1.00 cubic feet net?

1.00 cubic feet net. DD's own sealed range for the SL712 is 0.7 to 1.5 cubic feet, Qtc 0.93 to 0.75, and a maximally flat box would take 1.94 cubic feet. This cabinet sits inside that range, toward its smaller end, where the SL712 plays with more punch and stays inside Xmax at its full rated power. In 1.00 cubic feet the SL712 lands at Qtc 0.834, punchy, with a mild rise near resonance and extra midbass, with system resonance at 44.8 Hz. The box is 1.08 cu ft gross before the driver's displacement of 0.070 cu ft, which is DD's own figure.

What amplifier power should I run, and what impedance?

DD rate the SL712 at 1000 watts RMS. DD sells the SL712 in D2 and D4. The D2 is two 2 ohm coils, 4 ohms in series or 1 ohm in parallel; the D4 is two 4 ohm coils, 8 ohms in series or 2 ohms in parallel. DD publishes one set of Thiele-Small parameters for the model rather than a set per coil, so this cabinet is the same either way. A parallel load at or under 1 ohm needs an amplifier rated for it. Aim for roughly 700 to 1000 watts at the impedance you wire.

How does a wedge enclosure improve the sound in a trunk installation?

The angled seat-side face matches the roughly 20 degree lean of a factory rear seat, so the cabinet sits flat against it instead of leaving a wasted triangle. The vertical trunk-lid-side face carries the driver, firing rearward into the trunk cavity.

Where does the cone area figure come from?

DD publishes no Sd for any of its drivers. The 532.4 square centimetre figure behind this alignment is derived from DD's own published piston diameter, which they define as measured halfway across the surround, the convention Sd itself is defined from. DD publishes no Mms, Cms or DC resistance either.

What is the expected low-frequency extension?

Half power lands at 39.0 Hz anechoic, before any cabin gain. Qtc is 0.834. These figures exclude cabin gain, which in most vehicles adds real output below 40 Hz. DD publish the SL712's free-air resonance at 29.00 Hz.

Do I need to add polyfill or damping?

No. Polyfill is already installed as a light wall lining and the quantity is chosen so it does not change the acoustic volume. Do not add more.

Is the driver included, and are the threaded inserts installed?

No driver: this is an enclosure only. You receive the cabinet finished in plush black carpet, one side-mounted pre-wired terminal cup and the polyfill lining installed. DD Audio publishes no mounting hole locations for this driver, so the threaded inserts are not pressed before it ships. The threaded insert kit comes in the box instead: inserts sized to the woofer, the correct drill bit, allen-head screws, an allen key and woofer gasket tape. You set them when the woofer goes in.

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