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Proline X PO 8TW-S W W1V3 sealed wedge enclosure, product photos pending. Placeholder graphic reading Photos Coming Soon.

Performance Optimized · Datasheet

Performance Optimized Wedge Wide Sealed Triple 8" Enclosure JL Audio 8W1v3 · Triple 8" Sealed enclosure

Net volume
0.386 cu ft per driver, 1.16 cu ft total, after both dividers and JL Audio's published 0.018 cu ft displacement per driver
Max mounting depth
3.86 in required; 0.75 in clearance above the motor against the raked rear panel
External dimensions
40 in W × 13 in at the seat face H × 10.43 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
JL Audio 8W1v3Buy at Audio Intensity
  • Best For: Triple JL Audio 8W1v3 SUV Cargo-Floor Builds
  • Net Volume: 0.386 cu ft per Driver (1.16 cu ft Net Total)
  • Driver Match: Three JL Audio 8W1v3 (Dual 4 Ohm), matched
  • Construction: 3 Chambers | 40" Wide Wedge | V-Groove/Dado | Double 1.5" Baffle | 3 Terminal Cups

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge Wide
Compatible DriverJL Audio 8W1v3, quantity 3, matched. Direct fit
ConfigurationTriple 8 inch sealed wedge, 3 chambers, 1 driver per chamber
Mounting PositionSUV cargo floor, raked face against the rear seat back
Firing DirectionRearward toward the liftgate. Not a down fire design
External Width40 in
External Height13 in at the seat face
External Depth10.43 in at the base, tapering to 5.70 in at the top
Internal Volume, Gross1.26 cu ft total
Internal Volume, Net Acoustic0.386 cu ft per driver, 1.16 cu ft total, after both dividers and JL Audio's published 0.018 cu ft displacement per driver
Driver Mounting Depth3.86 in required; 0.75 in clearance above the motor against the raked rear panel
Alignment Per Driver8W1v3-4 Qtc 0.698, fc 58.9 Hz, F3 59.6 Hz anechoic
Woofer Openings3 at 7.087 in
Woofer LayoutOne row across the face
Frame Outer Diameter8.504 in
Fs / Qts / Qes / Qms35.4 Hz / 0.420 / 0.450 / 5.790
Vas / Sd / Xmax19.3 L / 211 cm2 / 8 mm
Driver Power Handling150 W RMS per driver, 450 W RMS for the set of 3 (thermal rating)
Recommended Amplifier60-90 W RMS per driver, 180-270 W RMS for the full set, at 2.67 ohms
Parameter SourceJL Audio 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 BracingTwo full-height 3/4 in dividers
Driver MountingThreaded inserts, stainless machine screws included
Terminal CupsThree Proline X ABS and carbon fiber composite, on the rear panel, one per chamber, pre wired 12 gauge OFC
Acrylic InsertGloss black acrylic baffle insert standard
DampingLight polyfill wall lining in every chamber, does not alter acoustic volume
CarpetPlush black
Shipping Weight53 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
0.386
cu ft per driver
System Qtc
0.70
sealed
Half power
59.6
Hz · F3
Xmax at
82
W RMS per driver · no filter
With 25 Hz subsonic
98
W RMS per driver · +20%
Amplifier, per driver
60–90
W RMS recommended
This enclosure holds 0.386 cu ft net per driver. In it the JL Audio 8W1v3-4 runs a system Qtc of 0.70 with half power at 59.6 Hz, and the cone reaches its 8.0 mm travel limit at 82 W per driver, below the driver’s 150 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 98 W per driver — +16 W, or 20 percent more power for the same 8.0 mm of travel.

00Sizing the amplifier

Every wattage on this panel is per driver. This cabinet holds three, so the amplifier feeds all three at once.

Per driver 60–90 W RMS  ×  3 drivers  =  full set 180–270 W RMS at 2.67 ohms
Look for a mono amplifier rated 180–270 W RMS at 2.67 ohms, the load the set wires to most easily. Travel sets the top here, not heat: past 98 W per driver the cone runs beyond Xmax even with the subsonic set, under the driver’s 150 W thermal rating. The top of the range needs the 25 Hz subsonic filter set; without it, keep each driver under 82 W, where the cone reaches Xmax unfiltered. Below the bottom of the range it will play, just with less headroom; above the top you are buying power the drivers cannot use.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 78.7
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 Dual 4 Ohm 78.7
Dual 4 Ohm · EBP 78.7
At 78.7 the 8W1v3-4 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

0.386 cu ft against a 19.3 L Vas.

α = Vas ÷ Vb = 1.76  ·  Fc = Fs√(α+1) = 59 Hz  ·  Qtc = 0.70
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
Dual 4 Ohm · Qtc 0.70, Fc 59 Hz, F3 59.6 Hz
The box lifts resonance from 35.4 Hz free-air to 59 Hz and half power lands at 59.6 Hz, anechoic, before any cabin gain. Figures are JL Audio’s published parameters; Qes and Qms reproduce the printed Qts. This cabinet holds three drivers in three separate sealed chambers of 0.386 cubic feet each, the volume plotted here.

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

PXmax = 82 W per driver unfiltered  →  98 W per driver with a 25 Hz subsonic
20 30 50 70 100 150 200 0 4 8 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 8.0 mm 82 W reaches Xmax here
Dual 4 Ohm · 82 W, no filterDual 4 Ohm · 98 W with subsonic at 25 Hz, 24 dB/octXmax 8.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 8.0 mm. Unfiltered that is 82 W per driver, reached first at 20 Hz. It sits under the 150 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 98 W per driver before hitting the same 8.0 mm. That is 20 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs35.40Hzfree-air resonance
Qts0.420Dual 4 Ohm
Vas19.30Lequivalent compliance
Sd211.0cm²effective piston area
Xmax8mmone-way linear travel
Pe150Wcontinuous RMS
SPL84.6dB1 W / 1 m, derived from T/S

Driver parameters as published by JL Audio 8W1v3-4 published specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Start with the size. The maker's recommended sealed size is 0.35 per driver, but the 3.86 in deep motor sets the top of the wedge at 5.70 in, and the smallest box that clears it holds 0.386 per driver. 0.386 cubic feet per driver puts the 8W1v3 at Qtc 0.698, resonance 58.9 Hz, half power 59.6 Hz anechoic: no peak, flat to the rolloff.

Measure the base depth, not the top. This cabinet is 10.43 in deep where it meets the floor, 5.70 at the top, 40 wide and 13 tall. In an SUV the 40 has to clear between the rear wheel wells at floor height, the base depth is measured from the seat back with the seat upright and latched, and the 13 has to clear the cargo cover.

All three terminal cups are on the rear panel, and the rear panel is the face that goes against the seat back. Wire all three before the box goes in, with enough slack to slide it into place; once the raked face is against the seat you cannot reach them.

Impedance. 8W1v3-4: wire for 2.67 ohms (coils in series, the three cups in parallel), the load most monoblocks are built to deliver full power into; 6 ohms is the other clean option (coils in parallel, the three in series). Work the load out before you buy the amplifier, not after.

Power. Size the amplifier for the set, not one driver: 60 to 90 W RMS per driver is 180 to 270 W RMS across all 3 at 2.67 ohms. On this driver travel sets the top, not heat: Xmax arrives at 98 W per driver with a 25 Hz subsonic, under the 150 W rating. Set the 25 Hz subsonic to use the top of that range; without it keep each driver under 82 W.

JL Audio's Qes and Qms reproduce the printed Qts within 3 percent, so the alignment rests on a self-consistent set.

Polyfill is in as a wall lining in every chamber. Do not add more: it makes the box act larger and walks Qtc off 0.70.

Before you order

Questions

Does this fit the JL Audio 8W1v3, and its coil versions?

Yes. Each opening is cut to 7.087 in for the 8.504 in frame, and the 3.86 in deep motor clears the raked rear panel with 0.75 in to spare. Coil versions of the JL Audio 8W1v3 share the frame, cutout and mounting depth, so any of them drops in. The alignment on this page is computed on the 8W1v3-4 parameters.

Run three matched drivers, same model and same coil, so every chamber sees the alignment on this page.

Why 0.386 cubic feet per driver, and what alignment does it target?

On JL Audio's published Fs 35.4 Hz, Qts 0.420 and Vas 19.3 liters, 0.386 cubic feet per driver gives Qtc 0.698, system resonance 58.9 Hz and half power 59.6 Hz.

The maker's recommended sealed size is 0.35 cubic feet per driver, but the 3.86 in deep motor sets the shallowest the wedge can be, so it comes down only to 0.386: no peak, flat to the rolloff.

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

JL Audio rates the 8W1v3 at 150 watts RMS per driver. Recommended amplifier: 60 to 90 W RMS per driver, 180 to 270 W RMS for the full set of 3. Travel, not heat, sets the top: the cone reaches Xmax at 98 W per driver with a 25 Hz subsonic set, under the 150 W rating. The top of that range needs the 25 Hz subsonic; without it keep each driver under 82 W.

Each 8W1v3-4 has two 4 ohm voice coils, 8 ohms in series or 2 ohms in parallel. With each driver's coils in series and the three cups in parallel, the three present 2.67 ohms to a mono amplifier. With each driver's coils in parallel and the three in series, they present 6 ohms. Three drivers do not reach the round loads a pair does, so check the result against your amplifier's minimum stable impedance before powering up.

Will it fit my SUV?

It is 40 inches wide, 13 tall and 10.43 deep at the base, tapering to 5.70 at the top. Measure between the rear wheel wells, the floor depth with the seat upright, and the height under your cargo cover.

The raked face goes against the seat back and the woofers fire toward the liftgate.

Why are all three terminal cups on the back?

Each driver has its own sealed chamber, and the center chamber has no side wall to take a cup. Putting all three on the rear panel gives a matching set, one cup per chamber.

Wire them at the amplifier end; there is no cross-chamber wiring inside the cabinet.

What is the expected low-frequency extension?

Anechoic F3 is 59.6 Hz per driver with system resonance at 58.9 Hz.

Those figures exclude cabin gain. An SUV cabin adds real output below about 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 as a light wall lining in every chamber, and the quantity is chosen so it does not change the acoustic volume.

Do not add more. Packing a sealed box makes it behave as though it were larger, which moves the alignment away from 0.386 cubic feet per driver.

Are the drivers included?

No. This is an enclosure only. You receive the cabinet finished in plush black carpet with the gloss black acrylic baffle insert, three pre-wired terminal cups on the rear panel, the polyfill lining in place, threaded inserts and stainless machine screws.

Bring three matched JL Audio 8W1v3 drivers. The cabinet is cut direct fit to them, not a general purpose 8 inch box.

Same series, same size

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