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Proline X PO 8Q-S W S84 sealed wedge enclosure, product photos pending. Placeholder graphic reading Photos Coming Soon.

Performance Optimized · Datasheet

Performance Optimized Wedge Wide Sealed Quad 8" Enclosure PowerBass S-84 · Quad 8" Sealed enclosure

Net volume
0.394 cu ft per driver, 1.58 cu ft total, after the divider and PowerBass's published 0.045 cu ft displacement per driver
Max mounting depth
3.50 in required; 2.51 in clearance above the motor against the raked rear panel
External dimensions
44 in W × 13 in at the seat face H × 11.84 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
PowerBass S-84Buy at Audio Intensity
  • Best For: Quad PowerBass S-84 SUV Cargo-Floor Builds
  • Net Volume: 0.394 cu ft per Driver (1.58 cu ft Net Total)
  • Driver Match: Four PowerBass S-84 (SVC), matched
  • Construction: 2 Chambers | 44" Wide Wedge | V-Groove/Dado | Double 1.5" Baffle | 2 Terminal Cups

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge Wide
Compatible DriverPowerBass S-84, quantity 4, matched. Direct fit
ConfigurationQuad 8 inch sealed wedge, 2 chambers, 2 drivers per chamber
Mounting PositionSUV cargo floor, raked face against the rear seat back
Firing DirectionRearward toward the liftgate. Not a down fire design
External Width44 in
External Height13 in at the seat face
External Depth11.84 in at the base, tapering to 7.10 in at the top
Internal Volume, Gross1.79 cu ft total
Internal Volume, Net Acoustic0.394 cu ft per driver, 1.58 cu ft total, after the divider and PowerBass's published 0.045 cu ft displacement per driver
Driver Mounting Depth3.50 in required; 2.51 in clearance above the motor against the raked rear panel
Alignment Per DriverS-84 Qtc 0.707, fc 67.4 Hz, F3 67.4 Hz anechoic
Woofer Openings4 at 7.000 in
Woofer LayoutOne row across the face
Frame Outer Diameter8.38 in
Fs / Qts / Qes / Qms41.0 Hz / 0.430 / 0.467 / 4.850
Vas / Sd / Xmax19.0 L / 206 cm2 / 7 mm
Driver Power Handling125 W RMS per driver, 500 W RMS for the set of 4 (thermal rating)
Recommended Amplifier50-70 W RMS per driver, 200-280 W RMS for the full set
Parameter SourcePowerBass 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 BracingOne full-height 3/4 in divider
Driver MountingThreaded inserts, stainless machine screws included
Terminal CupsTwo Proline X ABS and carbon fiber composite, side mounted, 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 Weight58 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
0.394
cu ft per driver
System Qtc
0.71
sealed
Half power
67.4
Hz · F3
Xmax at
69
W RMS per driver · no filter
With 25 Hz subsonic
78
W RMS per driver · +13%
Amplifier, per driver
50–70
W RMS recommended
This enclosure holds 0.394 cu ft net per driver. In it the PowerBass S-84 runs a system Qtc of 0.71 with half power at 67.4 Hz, and the cone reaches its 7.0 mm travel limit at 69 W per driver, below the driver’s 125 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 78 W per driver — +9 W, or 13 percent more power for the same 7.0 mm of travel.

00Sizing the amplifier

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

Per driver 50–70 W RMS  ×  4 drivers  =  full set 200–280 W RMS
Look for a mono amplifier rated 200–280 W RMS at the load your coil version wires to. Travel sets the top here, not heat: past 78 W per driver the cone runs beyond Xmax even with the subsonic set, under the driver’s 125 W thermal rating. 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 = 87.8
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 SVC 87.8
SVC · EBP 87.8
At 87.8 the S-84 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

0.394 cu ft against a 19.0 L Vas.

α = Vas ÷ Vb = 1.70  ·  Fc = Fs√(α+1) = 67 Hz  ·  Qtc = 0.71
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
SVC · Qtc 0.71, Fc 67 Hz, F3 67.4 Hz
The box lifts resonance from 41.0 Hz free-air to 67 Hz and half power lands at 67.4 Hz, anechoic, before any cabin gain. Figures are PowerBass’s published parameters; Qes and Qms reproduce the printed Qts. This cabinet holds four drivers in two sealed chambers of 0.788 cubic feet, two drivers to a chamber, so each driver works into 0.394 cubic feet and that is 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 7.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 69 W per driver unfiltered  →  78 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 7.0 mm 69 W reaches Xmax here
SVC · 69 W, no filterSVC · 78 W with subsonic at 25 Hz, 24 dB/octXmax 7.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 7.0 mm. Unfiltered that is 69 W per driver, reached first at 20 Hz. It sits under the 125 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 78 W per driver before hitting the same 7.0 mm. That is 13 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs41.00Hzfree-air resonance
Qts0.430SVC
Vas19.00Lequivalent compliance
Sd206.1cm²effective piston area
Xmax7mmone-way linear travel
Pe125Wcontinuous RMS
SPL86.3dB1 W / 1 m, derived from T/S

Driver parameters as published by PowerBass S-84 published specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Start with the size. 0.394 cubic feet per driver puts the S-84 at Qtc 0.707, resonance 67.4 Hz, half power 67.4 Hz anechoic: maximally flat, no peak, the lowest F3 a sealed box reaches without a lift. The maker's recommended sealed size is 0.46 per driver, larger than this, so the flat box stands.

Measure the base depth, not the top. This cabinet is 11.84 in deep where it meets the floor, 7.10 at the top, 44 wide and 13 tall. In an SUV the 44 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.

The two terminal cups are on the side panels, one per chamber, so they sit close to the wheel wells. Land the speaker wire on both before the box slides into its final spot, with slack to pull it forward again.

Two drivers share each chamber, so they have to match: same model, same coil, wired in phase. One driver reversed in a shared chamber pushes against its partner and the pair cancels instead of adding. Check polarity at each cup with a battery tap before the box goes in.

The load depends on which coil version you run, so settle the coil before you buy the amplifier; the wiring section lists the clean loads for each version.

Power. Size the amplifier for the set, not one driver: 50 to 70 W RMS per driver is 200 to 280 W RMS across all 4. On this driver travel sets the top, not heat: Xmax arrives at 78 W per driver with a 25 Hz subsonic, under the 125 W rating.

PowerBass'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 0.71.

Before you order

Questions

Does this fit the PowerBass S-84, and its coil versions?

Yes. Each opening is cut to 7.000 in for the 8.38 in frame, and the 3.50 in deep motor clears the raked rear panel with 2.51 in to spare. Coil versions of the PowerBass S-84 share the frame, cutout and mounting depth, so any of them drops in. The alignment on this page is computed on the S-84 parameters.

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

Why 0.394 cubic feet per driver, and what alignment does it target?

On PowerBass's published Fs 41.0 Hz, Qts 0.430 and Vas 19.0 liters, 0.394 cubic feet per driver gives Qtc 0.707, system resonance 67.4 Hz and half power 67.4 Hz.

Qtc 0.707 is maximally flat: the deepest response a sealed box gives without a lift near resonance.

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

PowerBass rates the S-84 at 125 watts RMS per driver. Recommended amplifier: 50 to 70 W RMS per driver, 200 to 280 W RMS for the full set of 4. Travel, not heat, sets the top: the cone reaches Xmax at 78 W per driver with a 25 Hz subsonic set, under the 125 W rating.

Loads depend on the coil version you run. Dual 4 ohm drivers, coils in series: 2 ohms with each chamber's pair in parallel, 8 ohms with each pair in series. Dual 2 ohm, coils in series: 1 ohm or 4 ohms the same two ways. Single 4 ohm: 1 ohm or 4 ohms. Use the lower load only on an amplifier rated stable there.

Will it fit my SUV?

It is 44 inches wide, 13 tall and 11.84 deep at the base, tapering to 7.10 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 two drivers per chamber instead of four chambers?

Four chambers would need three dividers, and on a 44 inch face that space is needed for the woofers. Two matched drivers in one sealed chamber move together and see the same pressure, so each behaves as if it had half the chamber to itself: 0.394 cubic feet per driver here.

It also gives two terminal cups, one per pair, which keeps the wiring to the amplifier simple.

What is the expected low-frequency extension?

Anechoic F3 is 67.4 Hz per driver with system resonance at 67.4 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 0.394 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, two side-mounted pre-wired terminal cups, the polyfill lining in place, threaded inserts and stainless machine screws.

Bring four matched PowerBass S-84 drivers. The cabinet is cut direct fit to them, not a general purpose 8 inch box.

Same series, same size

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