Shop
Proline X PO 12T-S W TW1 sealed wedge enclosure, product photos pending. Placeholder graphic reading Photos Coming Soon.

Performance Optimized · Datasheet

Performance Optimized Wedge Wide Sealed Triple 12" Enclosure JL Audio 12TW1 · Triple 12" Sealed enclosure

Net volume
0.650 cu ft per driver, 1.95 cu ft total, after both dividers and JL Audio's published 0.072 cu ft displacement per driver
Max mounting depth
4.61 in required; 1.03 in clearance above the motor against the raked rear panel
External dimensions
44 in W × 17 in at the seat face H × 12.13 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 12TW1Buy at Audio Intensity
  • Best For: Triple JL Audio 12TW1 SUV Cargo-Floor Builds
  • Net Volume: 0.650 cu ft per Driver (1.95 cu ft Net Total)
  • Driver Match: Three JL Audio 12TW1 (Dual 4 Ohm), matched
  • Construction: 3 Chambers | 44" 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 12TW1, quantity 3, matched. Direct fit
ConfigurationTriple 12 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 Width44 in
External Height17 in at the seat face
External Depth12.13 in at the base, tapering to 5.94 in at the top
Internal Volume, Gross2.25 cu ft total
Internal Volume, Net Acoustic0.650 cu ft per driver, 1.95 cu ft total, after both dividers and JL Audio's published 0.072 cu ft displacement per driver
Driver Mounting Depth4.61 in required; 1.03 in clearance above the motor against the raked rear panel
Alignment Per Driver12TW1-4 Qtc 0.892, fc 54.5 Hz, F3 45.5 Hz anechoic
Woofer Openings3 at 11.063 in
Woofer LayoutOne row across the face
Frame Outer Diameter12.362 in
Fs / Qts / Qes / Qms32.4 Hz / 0.530 / 0.560 / 11.070
Vas / Sd / Xmax33.7 L / 436 cm2 / 10 mm
Driver Power Handling300 W RMS per driver, 900 W RMS for the set of 3 (thermal rating)
Recommended Amplifier210-300 W RMS per driver, 630-900 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 Weight67 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
0.650
cu ft per driver
System Qtc
0.89
sealed
Half power
45.5
Hz · F3
Xmax at
317
W RMS per driver · no filter
With 25 Hz subsonic
334
W RMS per driver · +5%
Amplifier, per driver
210–300
W RMS recommended
This enclosure holds 0.650 cu ft net per driver. In it the JL Audio 12TW1-4 runs a system Qtc of 0.89 with half power at 45.5 Hz, and the cone reaches its 10.0 mm travel limit at 317 W per driver, above the driver’s 300 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 334 W per driver — +16 W, or 5 percent more power for the same 10.0 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 210–300 W RMS  ×  3 drivers  =  full set 630–900 W RMS at 2.67 ohms
Look for a mono amplifier rated 630–900 W RMS at 2.67 ohms, the load the set wires to most easily. The top is the driver’s 300 W thermal rating; with the 25 Hz subsonic set the cone still has travel to spare there, reaching Xmax only at 334 W. 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 = 57.9
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 Dual 4 Ohm 57.9
Dual 4 Ohm · EBP 57.9
At 57.9 the 12TW1-4 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

0.650 cu ft against a 33.7 L Vas.

α = Vas ÷ Vb = 1.83  ·  Fc = Fs√(α+1) = 55 Hz  ·  Qtc = 0.89
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
Dual 4 Ohm · Qtc 0.89, Fc 55 Hz, F3 45.5 Hz
The box lifts resonance from 32.4 Hz free-air to 55 Hz and half power lands at 45.5 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 0.650 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 10.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 317 W per driver unfiltered  →  334 W per driver with a 25 Hz subsonic
20 30 50 70 100 150 200 0 4 8 12 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 10.0 mm 317 W reaches Xmax here
Dual 4 Ohm · 317 W, no filterDual 4 Ohm · 334 W with subsonic at 25 Hz, 24 dB/octXmax 10.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 10.0 mm. Unfiltered that is 317 W per driver, reached first at 33 Hz. It sits above the 300 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 334 W per driver before hitting the same 10.0 mm. That is 5 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs32.40Hzfree-air resonance
Qts0.530Dual 4 Ohm
Vas33.70Lequivalent compliance
Sd436.0cm²effective piston area
Xmax10mmone-way linear travel
Pe300Wcontinuous RMS
SPL85.0dB1 W / 1 m, derived from T/S

Driver parameters as published by JL Audio 12TW1-4 published specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Start with the size. 0.650 cubic feet per driver puts the 12TW1 at Qtc 0.892, resonance 54.5 Hz, half power 45.5 Hz anechoic. That is JL Audio's number, not ours: the cabinet is built to the maker's recommended sealed size. Butterworth on these figures wants 1.53, which on this platform means 19.5 in deep at the base. It is a small lift near resonance, 0.6 dB above flat.

Measure the base depth, not the top. This cabinet is 12.13 in deep where it meets the floor, 5.94 at the top, 44 wide and 17 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 17 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. 12TW1-4: 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: 210 to 300 W RMS per driver is 630 to 900 W RMS across all 3 at 2.67 ohms.

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 0.89.

Before you order

Questions

Does this fit the JL Audio 12TW1, and its coil versions?

Yes. Each opening is cut to 11.063 in for the 12.362 in frame, and the 4.61 in deep motor clears the raked rear panel with 1.03 in to spare. Coil versions of the JL Audio 12TW1 share the frame, cutout and mounting depth, so any of them drops in. The alignment on this page is computed on the 12TW1-4 parameters.

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

Why 0.650 cubic feet per driver, and what alignment does it target?

On JL Audio's published Fs 32.4 Hz, Qts 0.530 and Vas 33.7 liters, 0.650 cubic feet per driver gives Qtc 0.892, system resonance 54.5 Hz and half power 45.5 Hz.

The cabinet is sized to the maker's recommended sealed size, 0.65 cubic feet per driver, to keep it realistic for a cargo floor. Maximally flat would need 1.53 cubic feet per driver; this size trades a little low end for a compact box and a small lift near resonance, 0.6 dB above flat.

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

JL Audio rates the 12TW1 at 300 watts RMS per driver. Recommended amplifier: 210 to 300 W RMS per driver, 630 to 900 W RMS for the full set of 3.

Each 12TW1-4 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 44 inches wide, 17 tall and 12.13 deep at the base, tapering to 5.94 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 45.5 Hz per driver with system resonance at 54.5 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 0.650 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 12TW1 drivers. The cabinet is cut direct fit to them, not a general purpose 12 inch box.

Same series, same size

Other Performance Optimized models