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Proline X PO 8-S W 2508GESP sealed wedge, front baffle with gloss black insert and pre-wired leads, 11.45 by 11.75 inches.
Proline X PO 8-S W 2508GESP sealed wedge, side profile with recessed terminal cup, 13.06 inch base, 11.75 inches tall.

Performance Optimized · Datasheet

DD Audio 2508g ESP Box: Sealed 8" Wedge Enclosure Single 8" Sealed enclosure

Net volume
0.33 cu ft
Max mounting depth
7.190 in available, 6.690 in required
Cutout
8.000 in
External dimensions
11.45 in W × 11.75 in at the seat face H × 13.06 in at the base D
Front baffle
1.5 in, double baffle
Buy at Audio IntensityFactory-direct, ships from Tullahoma
DD Audio 2508g ESPBuy at Audio Intensity
  • Best For: DD Audio 2508g ESP Trunk-Fit Builds
  • Net Volume: 0.33 cu ft (0.42 cu ft Gross)
  • Alignment: Qtc 0.685, fc 51.4 Hz, F3 53.1 Hz
  • Driver Match: DD Audio 2508g ESP (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 2508g ESP, D2 or D4, quantity 1. Direct fit
ConfigurationSingle 8 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 Width11.45 in
External Height11.75 in at the seat face
External Depth13.06 in at the base, tapering to 8.78 in at the top
Internal Volume, Gross0.42 cu ft
Internal Volume, Net Acoustic0.33 cu ft
AlignmentQtc 0.685, fc 51.4 Hz, F3 53.1 Hz anechoic
Driver Cutout8.000 in
Driver Mounting Depth7.190 in available, 6.690 in required
Frame Outer Diameter8.950 in, as published by DD Audio
Driver Displacement0.080 cu ft, as published by DD Audio
Cone Area (derived)266.3 cm2, from DD's published piston diameter; DD publish no Sd
Power Handling1200 watts RMS
ImpedanceD2: 4 ohms in series or 1 ohm in parallel; D4: 8 ohms in series or 2 ohms in parallel
Xmax20 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
Shipping Weight20 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
0.33
cu ft
System Qtc
0.69
sealed
Half power
53.1
Hz · F3
Xmax at
1669
W RMS · no filter
With 25 Hz subsonic
2169
W RMS · +30%
Amplifier
1200
W RMS recommended
This enclosure holds 0.33 cu ft net . In it the DD Audio 2508g ESP runs a system Qtc of 0.69 with half power at 53.1 Hz, and the cone reaches its 20.0 mm travel limit at 1669 W, above the driver’s 1200 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 2169 W — +500 W, or 30 percent more power for the same 20.0 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 67.7
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 2508g ESP, D2 or D4 (DD publish one shared table) 67.7
2508g ESP, D2 or D4 (DD publish one shared table) · EBP 67.7
At 67.7 the 2508g ESP sits in the transition band, not the sealed band. That is not a mismatch: a transition motor works in either alignment, and sealed buys a smaller box and a gentler roll-off at the cost of some low-end output. Stage 02 shows what this airspace actually does with it.

02What the box does to it

0.33 cu ft against a 4.6 L Vas.

α = Vas ÷ Vb = 0.50  ·  Fc = Fs√(α+1) = 51 Hz  ·  Qtc = 0.69
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
2508g ESP, D2 or D4 (DD publish one shared table) · Qtc 0.69, Fc 51 Hz, F3 53.1 Hz
The box lifts resonance from 42.0 Hz free-air to 51 Hz and half power lands at 53.1 Hz, anechoic, before any cabin gain. Figures are DD Audio’s own published table for the 2508g ESP, which covers the D2 and D4 alike. DD publish no cone area; the 266.3 square centimetre figure is derived from their published piston diameter. At 0.33 cubic feet net the 2508g ESP sits at Qtc 0.69: just under maximally flat, slightly dry.

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

PXmax = 1669 W unfiltered  →  2169 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 8 16 24 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 20.0 mm 1669 W reaches Xmax here
2508g ESP, D2 or D4 (DD publish one shared table) · 1669 W, no filter2508g ESP, D2 or D4 (DD publish one shared table) · 2169 W with subsonic at 25 Hz, 24 dB/octXmax 20.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 20.0 mm. Unfiltered that is 1669 W, reached first at 20 Hz. It sits above the 1200 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 2169 W before hitting the same 20.0 mm. That is 30 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs42.00Hzfree-air resonance
Qts0.5602508g ESP, D2 or D4 (DD publish one shared table)
Vas4.64Lequivalent compliance
Sd266.3cm²effective piston area
Xmax20mmone-way, as DD publish it, with no stated measurement basis
Pe1200Wcontinuous RMS
SPL79.3dB1 W / 1 m, derived from T/S

Driver parameters as published by DD Audio published 2508g ESP specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

0.33 cubic feet net, solved from DD's published Fs, Qts and Vas. A maximally flat box at Qtc 0.707 would be 0.28 cubic feet, but the baffle has to carry DD's 8.950 inch frame and the cabinet has to clear the 6.690 inch motor, and the smallest wedge that does both holds 0.33. In it the 2508g ESP lands at Qtc 0.685, maximally flat, the reference musical alignment, with system resonance at 51.4 Hz. Half power lands at 53.1 Hz anechoic, before any cabin gain.

DD publishes no Sd for any of its drivers. The 266.3 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 2508g ESP 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 13.06 inches deep at the trunk floor, 8.78 at the top, and 11.45 wide. It is deeper at the base than it is tall, because the 2508g ESP carries a 6.690 in motor and the cabinet has to clear it.

Before you order

Questions

Will this enclosure fit both coil versions of the 2508g ESP?

Yes. DD sells the 2508g ESP 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 8.000 in and the mounting depth allowance is 7.190 in.

Why 0.33 cubic feet net?

0.33 cubic feet net, solved from DD's published Fs, Qts and Vas. A maximally flat box at Qtc 0.707 would be 0.28 cubic feet, but the baffle has to carry DD's 8.950 inch frame and the cabinet has to clear the 6.690 inch motor, and the smallest wedge that does both holds 0.33. In it the 2508g ESP lands at Qtc 0.685, maximally flat, the reference musical alignment, with system resonance at 51.4 Hz. The box is 0.42 cu ft gross before the driver's displacement of 0.080 cu ft, which is DD's own figure.

What amplifier power should I run, and what impedance?

DD rate the 2508g ESP at 1200 watts RMS. DD sells the 2508g ESP 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 840 to 1200 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 266.3 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 53.1 Hz anechoic, before any cabin gain. Qtc is 0.685. These figures exclude cabin gain, which in most vehicles adds real output below 40 Hz. DD publish the 2508g ESP's free-air resonance at 42.00 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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