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Performance Optimized · Datasheet

Performance Optimized Wedge Sealed Dual 8" Enclosure JL Audio 8W7AE · Dual 8" Sealed enclosure

Net volume
0.875 cu ft per chamber after the divider and JL's published 1.7 L displacement per driver
Max mounting depth
6.83 in required; 4.50 in clearance above the motor against the raked rear panel
External dimensions
32.00 in W × 11 in at the seat face H × 16.83 in at the base D
Front baffle
1.5 in double baffle, outer layer machined as a flush recess
Buy at Audio IntensityFactory-direct, ships from Tullahoma
  • Best For: Dual JL Audio 8W7AE-3 Trunk-Fit Builds
  • Net Volume: 0.875 cu ft per chamber (1.92 cu ft Gross Total)
  • Driver Match: Pair of JL Audio 8W7AE-3 (single 3 ohm), matched
  • Construction: Dual Chamber | Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | 1 Shared Terminal Cup | Threaded Inserts

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge
Compatible DriverJL Audio 8W7AE-3, quantity 2. Direct fit
ConfigurationDual 8 inch, two separate chambers, 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 Width32.00 in, the dual width cap
External Height11 in at the seat face
External Depth16.83 in at the base, tapering to 12.83 in at the top
Internal Volume, Gross1.92 cu ft total
Internal Volume, Net Acoustic0.875 cu ft per chamber after the divider and JL's published 1.7 L displacement per driver
Driver Mounting Depth6.83 in required; 4.50 in clearance above the motor against the raked rear panel
Alignment per chamberQtc 0.798, fc 45.9 Hz, F3 41.3 Hz anechoic
JL Recommended Enclosure0.875 cu ft sealed (Qtc 0.798, F3 41.3 Hz), 1.0 cu ft ported
Woofer Opening6.94 in (176 mm), two, JL's published mounting hole
Frame Outer Diameter8.5 in (216 mm)
Bolt Circle7.39 in (188 mm), JL spec; threaded inserts pressed
Driver Displacement1.7 L / 0.06 cu ft, JL spec
Fs / Qts / Qes / Qms35.2 Hz / 0.612 / 0.654 / 9.5
Vas / Mms / Cms / Bl17.4 L / 100 g / 0.204 mm/N / 9.7 N/A
Driver Sd245 cm2
Xmax19 mm one way, JL spec (voice coil overhang method)
Driver Sensitivity82.7 dB at 1 W / 1 m, JL spec
Driver Power Handling500 W RMS per driver
Wiring OptionsSingle 3 ohm coil; the pair wires to 1.5 ohm parallel or 6 ohm series
Parameter SourceJL Audio 8W7AE-3 published specifications
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Internal BracingFull-height 3/4 in divider
Driver MountingThreaded inserts pressed on JL's bolt circle, stainless machine screws included
Terminal CupsOne Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC to both driver positions
Acrylic InsertGloss black acrylic baffle insert standard
DampingLight polyfill wall lining in both chambers, does not alter acoustic volume
CarpetPlush black
Shipping Weight51 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
0.87
cu ft per chamber
System Qtc
0.80
sealed
Half power
41.3
Hz · F3
Xmax at
356
W RMS · no filter
With 25 Hz subsonic
431
W RMS · +21%
Amplifier
500
W RMS recommended
This enclosure holds 0.87 cu ft net per chamber. In it the JL Audio 8W7AE-3 runs a system Qtc of 0.80 with half power at 41.3 Hz, and the cone reaches its 19.0 mm travel limit at 356 W, below the driver’s 500 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 431 W — +75 W, or 21 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 = 53.8
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 single 3 ohm 53.8
single 3 ohm · EBP 53.8
At 53.8 the 8W7AE-3 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

0.87 cu ft against a 17.4 L Vas.

α = Vas ÷ Vb = 0.70  ·  Fc = Fs√(α+1) = 46 Hz  ·  Qtc = 0.80
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
single 3 ohm · Qtc 0.80, Fc 46 Hz, F3 41.3 Hz
The box lifts resonance from 35.2 Hz free-air to 46 Hz and half power lands at 41.3 Hz, anechoic, before any cabin gain. Figures are JL Audio’s published 8W7AE-3 parameters, and they hold together: Qes and Qms reproduce the printed Qts, and the moving mass and compliance reproduce the 35.2 Hz resonance and 17.4 liter Vas. Each chamber of this dual holds 0.875 cubic feet, JL’s own recommended sealed volume, so per driver it is the single wedge twice over.

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 = 356 W unfiltered  →  431 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 356 W reaches Xmax here
single 3 ohm · 356 W, no filtersingle 3 ohm · 431 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 356 W, reached first at 21 Hz. It sits under the 500 W the driver can take thermally, so the enclosure sets the ceiling, not the voice coil. 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 431 W before hitting the same 19.0 mm. That is 21 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs35.20Hzfree-air resonance
Qts0.612single 3 ohm
Vas17.40Lequivalent compliance
Sd245.0cm²effective piston area
Xmax19mmone-way linear travel
Pe500Wcontinuous RMS
SPL82.5dB1 W / 1 m, derived from T/S

Driver parameters as published by JL Audio 8W7AE-3 published specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Built to JL's own sealed box, 0.875 cubic feet per chamber, Qtc 0.798. Butterworth on these numbers wants 1.84, a 29 inch box for one 8; JL's figure is the practical one and it is punchy, not boomy.

Two chambers at 0.875 each, pinned at the 32 inch cap and 11 tall, so it runs 16.83 deep at the base: deeper than it is tall. Measure the trunk floor first. Single 3 ohm coils: the pair is 1.5 ohms parallel or 6 series.

Cut is 6.94 (176 mm), JL's own mounting hole, and the inserts are pressed on JL's 7.39 bolt circle. It is sealed, so leave the polyfill as it is and run it at 500 watts or under per driver.

Before you order

Questions

Does this fit the JL Audio 8W7AE-3, and will any other 8 inch fit?

The 8W7AE-3, yes. The baffle is cut to 6.94 in (176 mm), JL's published mounting hole, under the 8.5 in (216 mm) frame. The 6.83 inch motor clears the raked rear panel with 4.50 inch to spare, and JL sells the 8W7AE in one version, a single 3 ohm coil, so there is no variant to choose. Run two so the chambers match.

Any other 8, no. The airspace is built around the 8W7AE's 0.612 Qts and 17.4 liters of Vas, and most 8 inch drivers are far shallower than its 6.83 inch motor; a different woofer that happened to drop into the hole would not see the alignment printed on this page.

Why 0.875 cubic feet per chamber, and what alignment does it target?

It is JL's own recommended sealed volume for the 8W7AE. On JL's published Fs 35.2 Hz, Qts 0.612 and Vas 17.4 liters it gives Qtc 0.798, system resonance 45.9 Hz and half power 41.3 Hz, exactly the figures JL prints for that box.

Qtc 0.80 is a little above maximally flat: a small lift near resonance and a firm, punchy midbass. The flat box on the same figures would be 1.84 cubic feet, more than double, which is not a practical cabinet for one 8 inch driver.

What amplifier power should I run, and how should I wire it?

JL rates the 8W7AE-3 at 500 watts RMS per driver, so target 350 to 500 watts RMS per driver at the final load.

Each 8W7AE-3 has a single 3 ohm voice coil. Two in parallel present 1.5 ohms; two in series present 6 ohms. Use 1.5 ohms only if your amplifier is rated stable there; otherwise wire the pair in series for 6 ohms. Confirm your amplifier's minimum stable impedance first.

Why the wedge angle, and why rear-firing into the trunk?

The seat-side face carries a 20 degree rake that matches the lean of a factory rear seat back, so the cabinet sits flush against it and the cargo space in front stays usable. The baffle is the vertical trunk-lid-side face, so the drivers fire rearward into the trunk cavity.

The trunk acts as an acoustic extension for the sealed box, and the cabin adds real output below 50 Hz, so in-vehicle response runs deeper than the anechoic 41.3 Hz on this page.

Why two separate chambers instead of one shared volume?

Two drivers sharing one sealed volume load each other: each driver's compression stroke becomes the pressure the other works against, which blurs the alignment either would have alone. A bonded full-height 3/4 inch divider gives each driver its own 0.875 cubic feet and its own polyfill.

It also means a failure in one driver does not unload the other, and the alignment on this page is the alignment in each chamber, not an average across a shared box.

What is the expected low-frequency extension?

Anechoic F3 is 41.3 Hz per chamber with system resonance at 45.9 Hz. Above Qtc 0.707 F3 sits below fc, so the response carries a small lift near resonance before it rolls off.

Those figures exclude cabin gain. In a car the cabin's transfer function adds real output below 50 Hz, so in-vehicle response runs deeper than the numbers above.

Do I need to add polyfill or damping?

No. Polyfill is already installed in both chambers as a light wall lining to control internal reflections, and the quantity is chosen so it does not change the acoustic volume.

Do not add more. Packing a sealed box with fill makes it behave as though it were larger, which walks the alignment away from the 0.875 cubic feet per chamber this cabinet was built to.

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 with the gloss black acrylic baffle insert, one side-mounted pre-wired terminal cup to both positions, the polyfill lining already in place, and stainless machine screws.

The threaded inserts are already pressed: JL publishes a 7.39 inch bolt circle for the 8W7AE, so we drill to it at the shop. The pair of JL Audio 8W7AE-3 is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 8 inch box.

Same series, same size

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