Proline X PO 13-S DF TW5 single sealed down fire enclosure, product photos pending. Placeholder graphic reading Photos Coming Soon.

Performance Optimized · Datasheet

Performance Optimized Down Fire Sealed 13" Enclosure | JL Audio 13TW5v2 Single 13" Sealed enclosure

Net volume
0.80 cu ft after 0.052 displacement
Max mounting depth
2.638 in required
External dimensions
30 in W × 6.25 in in the down fire position H × 15 in D
Front baffle
1.5 in double baffle, also the mounting substrate
Buy at Audio Intensity
  • Alignment: 0.80 cu ft net. Qtc 1.014 (13TW5v2-4) / 0.939 (13TW5v2-2), F3 41.2 to 41.3 Hz
  • Driver: JL Audio 13TW5v2, 600 W RMS, 11 mm Xmax, 2.638 in mounting depth, the shallowest in the program
  • Mounting: WOOD SCREWS into the 1.5 in baffle. No threaded inserts, the flange is only 0.236 in per side
  • Standoffs: Included, 1.75 in, shipped uninstalled. Installed height near 8.00 in
  • Cabinet: 30"W x 15"D x 6.25"H in down fire position, excludes standoffs, square corners

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Down Fire
Compatible DriverJL Audio 13TW5v2, quantity 1. Direct fit, either coil
ConfigurationSingle 13 inch, sealed down fire
Mounting PositionTrunk or cargo floor, baffle facing down on standoffs
Firing DirectionDownward. Feet ship uninstalled, so front or up firing is also possible
External Width30 in
External Depth15 in
External Height6.25 in in the down fire position, excludes standoffs
Installed Height8.00 in including the 1.75 in standoff
Internal Volume, Gross0.8603 cu ft
Internal Volume, Net Acoustic0.80 cu ft after 0.052 displacement
JL Published Target0.80 cu ft, stated as both minimum and maximum. Ported not recommended
Alignment, 13TW5v2-4Qtc 1.014, fc 52.8 Hz, F3 41.3 Hz anechoic
Alignment, 13TW5v2-2Qtc 0.939, fc 50.9 Hz, F3 41.2 Hz anechoic
Woofer Opening12.52 in (318 mm) direct fit
Driver Mounting Depth2.638 in required
Driver MountingWood screws direct into the 1.5 in baffle. No threaded inserts: the 12.992 in frame against a 12.52 in cutout leaves only 0.236 in of flange per side
Driver Power Handling600 W RMS
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery, square corners
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, also the mounting substrate
Internal BracingWindowed U-brace, dadoed to front, top and back
Terminal CupsOne Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC
StandoffsIncluded, 1.75 in, shipped uninstalled
DampingLight polyfill wall lining, does not alter acoustic volume
CarpetPlush black
Weight32 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Performance in this enclosure

Net airspace
0.80
cu ft per chamber
System Qtc
0.94–1.01
sealed
Half power
41.2–41.3
Hz · F3
Xmax at
538
W RMS · no filter
With 25 Hz subsonic
558
W RMS · +4%
Amplifier
600
W RMS recommended
This enclosure holds 0.80 cu ft net per chamber. In it the JL Audio 13TW5v2 runs a system Qtc of 0.94–1.01 with half power at 41.2–41.3 Hz, and the cone reaches its 11.0 mm travel limit at 538 W, below the driver’s 600 W thermal rating, so travel is what stops you here, not heat. A 25 Hz subsonic filter adds little here: 558 W against 538 W, 4 percent. The box already resonates at 51–53 Hz, so its own rolloff has removed most of what the filter would have stopped.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 50.2–51.0
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 13TW5v2-2 51.0 13TW5v2-4 50.2
13TW5v2-2 · EBP 51.013TW5v2-4 · EBP 50.2
At 50.2–51.0 the 13TW5v2 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

0.80 cu ft against a 64.0 L Vas.

α = Vas ÷ Vb = 2.83  ·  Fc = Fs√(α+1) = 51–53 Hz  ·  Qtc = 0.94–1.01
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
13TW5v2-2 · Qtc 0.94, Fc 51 Hz, F3 41.2 Hz13TW5v2-4 · Qtc 1.01, Fc 53 Hz, F3 41.3 Hz
The box lifts resonance from 26.0–27.6 Hz free-air to 51–53 Hz and half power lands at 41.2–41.3 Hz, anechoic, before any cabin gain. This enclosure ships without a driver, so both coil variants the maker offers are plotted. They do not load the same box the same way.

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 11.0 mm, and in this alignment a subsonic filter barely moves it.

PXmax = 538–542 W unfiltered  →  558–567 W 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 11.0 mm 538 W reaches Xmax here
13TW5v2-2 · 538 W, no filter13TW5v2-4 · 542 W, no filter13TW5v2-2 · 567 W with subsonic at 25 Hz, 24 dB/oct13TW5v2-4 · 558 W with subsonic at 25 Hz, 24 dB/octXmax 11.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 11.0 mm. Unfiltered that is 538 W, reached first at 34 Hz. It sits under the 600 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, and they sit almost on top of the solid ones: 558 W against 538 W. At 51–53 Hz the filter sits well below resonance, where the sealed alignment has already rolled the cone off at 12 dB/oct, so there is little wasted travel left for it to recover. Set it anyway to keep road rumble out of the cone, but do not size the amplifier around it.
ParamValueUnitNote
Fs26.00 / 27.60Hzfree-air resonance
Qts0.480 / 0.53013TW5v2-2 / 13TW5v2-4
Vas64.00 / 60.30Lequivalent compliance
Sd634.0cm²effective piston area
Xmax11mmone-way linear travel
Pe600Wcontinuous RMS
SPL85.3dB1 W / 1 m, derived from T/S

Driver parameters as published by loudspeakerdatabase.com. Curves computed against this enclosure’s actual net airspace.

Installer's take

Read the mounting line before you quote this one. It does NOT have threaded inserts. The TW5v2's flange is 0.236 inches wide per side and there is nowhere to put one, so it takes wood screws straight into the 1.5 inch baffle. Pilot them, do not gun them in, and tell the customer not to pull the driver more than they have to.

Measure the installed height. The cabinet is 6.25 tall and the standoffs add 1.75, so you are planning around 8.00 inches.

JL fixed the volume at 0.80 with no range and no ported option, so both coils land high: Qtc 1.014 on the 13TW5v2-4 and 0.939 on the 13TW5v2-2. That is the driver's specified alignment, not a choice we made, and there is no bigger box to move to.

Mounting depth is 2.638 inches, the shallowest driver in the program. The cabinet height is set by airspace, not by motor clearance, so there is generous room over the motor.

Polyfill is already in as a wall lining. Adding more makes the box act larger and walks the alignment off JL's number.

Questions

Does this enclosure use threaded inserts?

No, and that is a deliberate departure from the rest of the Performance Optimized range. The TW5v2's frame measures 12.992 inches across against a 12.52 inch cutout, which leaves 0.236 inches of flange per side. There is not enough material there to land an insert.

The driver mounts with wood screws direct into the 1.5 inch double baffle instead. Pilot the holes, do not overdrive them, and treat repeated removal with more care than you would an insert, because wood screws do not tolerate being cycled the way machine screws into metal do.

Why 0.80 cubic feet, and can I go bigger?

JL publishes 0.80 cubic feet for the TW5v2 as both the minimum and the maximum sealed volume. It is a single figure rather than a range, and they do not recommend a ported enclosure for this driver at all.

So no, there is no larger box on offer. A bigger sealed cabinet would lower system Qtc but would put the driver outside what it is specified for. This cabinet is built to the number JL gives.

What amplifier power should I run?

The TW5v2 is rated 600 watts RMS, so target 600 watts RMS at the final impedance.

The 13TW5v2-4 is a single 4 ohm coil and the 13TW5v2-2 a single 2 ohm. Wire to whichever your amplifier is happiest driving.

How tall is this once the standoffs are on?

The cabinet is 6.25 inches tall measured in the down fire position, excluding standoffs. The standoffs hold 1.75 inches under the baffle, so plan around a finished stack of roughly 8.00 inches.

The footprint is the standard Performance Optimized down fire platform, 30 inches wide by 15 deep.

Why is the front baffle double-layered?

The baffle is two bonded 3/4 inch sheets, 1.5 inches through. On most Performance Optimized cabinets that is about stiffness. On this one it is also structural to the mounting, because the driver screws into it directly rather than into inserts.

A wood screw into a single 3/4 inch panel is a weak joint under a subwoofer's reaction load. Into 1.5 inches of bonded MDF it has real thread engagement, which is what makes screw mounting acceptable here.

What is the expected low-frequency extension?

Anechoic F3 lands at 41.2 to 41.3 Hz depending on coil, with system Qtc between 0.94 and 1.01. Those are high Q figures, which follows from JL fixing the sealed volume at 0.80 rather than from anything about the cabinet.

Those figures are anechoic and exclude cabin gain. In a car the transfer function of the cabin adds real output below 50 Hz, so in-vehicle response runs deeper than the number above.

Do I need to add polyfill or damping?

No. Polyfill is already installed 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 would move the alignment off the 0.80 cubic feet JL specifies.

Is the JL Audio 13TW5v2 included?

No. This is an enclosure only. You receive the cabinet finished in plush black carpet, with a side-mounted pre-wired terminal cup, the standoffs, mounting screws and the polyfill lining already in place.

The TW5v2 is purchased separately. The cabinet is cut direct fit to that driver, so it is not a general purpose 13 inch box.

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