Proline X PO 10-S DF CLUB sealed down fire enclosure for the JBL Club 102SL, front panel on 1.75 inch feet, 30 by 5.3 inches.

Proline X PO 10-S DF CLUB sealed down fire enclosure, end panel with recessed terminal cup, 15 by 5.3 inches.

Proline X

Performance Optimized Down Fire Sealed 10" Enclosure | JBL Club 102SL

Q: Does this fit the JBL Club 102SL at either impedance setting, and will any other 10 inch fit?

The Club 102SL, yes, at either switch position: the SSI switch changes only the electrical load, not the frame. The baffle is cut to JBL's 9.00 in (228.6 mm) cutout, and the 10.52 in (267.3 mm) frame covers it with margin. The 3.25 inch motor clears the cabinet with 1.26 inch to spare.Any other 10, no. The airspace is chosen around the Club 102SL's 1.097 Qts and 24.4 liters of Vas at 4 ohms, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

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

JBL rates the Club 102SL at 350 watts RMS and 1050 watts peak, so target 244 to 350 watts RMS at the final load.The Club 102SL has one voice coil and JBL's Selectable Smart Impedance (SSI) switch, which sets it to 2 or 4 ohms without rewiring. The 4 ohm setting is the tighter alignment in this box; 2 ohms draws more power from a 2 ohm stable mono amplifier. Turn the amplifier off before switching. Confirm your amplifier's minimum stable impedance first.

Q: How tall is this once the standoffs are on?

The cabinet is 5.26 inches tall measured in the down fire position, and that figure excludes the standoffs. The standoffs hold 1.75 inches under the baffle, so plan your space around a finished stack of roughly 7.01 inches.The footprint is the standard Performance Optimized down fire platform, 30.00 inches wide by 15.00 deep. Height is the only dimension solved to the driver.

Q: Why is the front baffle double-layered?

The baffle is two bonded 3/4 inch sheets, 1.5 inches through. A single 3/4 inch panel flexes under the pressure a sealed box builds at 350 watts, which smears output and works the driver loose over time.The outer layer is machined as a flush recess to JBL's 10.52 inch frame, so the driver bolts to the inner layer.

Q: What is the expected low-frequency extension?

Anechoic F3 is 37.4 Hz at the 4 ohm setting, with system resonance at 54.6 Hz. Above Qtc 0.707 a sealed box peaks before it rolls off: this one rises about 5 dB near 60 Hz and is back at its reference level around 42 Hz, so the F3 sits below the resonance rather than at it.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.

Q: 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 walks the alignment away from the 0.60 cubic feet this cabinet was built to.

Q: 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, one side-mounted pre-wired terminal cup, the polyfill lining already in place, the standoffs, and a threaded insert kit with stainless machine screws.The inserts ship loose on purpose: JBL prints no bolt circle for the Club 102SL, so you set the driver in the recess, mark its holes, drill and press the inserts. We sell the JBL Club 102SL separately.

SKU: PO 10-S DF CLUB

QUICK SPECS

Alignment: 0.60 cu ft net, Qtc 1.71 at 4 ohm, F3 37.4 Hz, +5 dB peak near 60 Hz
Driver: JBL Club 102SL, 350 W RMS, 3.25 in mounting depth
Standoffs: Included, 1.75 in, shipped uninstalled. Installed height near 7.01 in
Cabinet: 30.00"W x 15.00"D x 5.26"H in down fire position, excludes standoffs, square corners

Shipping Included No freight charges at checkout. What you see is what you pay.

Built in Tennessee CNC cut from 3/4" Langboard Elite MDF. V-groove and dado joinery.

Advanced Terminal Cup Built in-house. ABS/Carbon Fiber. Stainless steel hardware. Copper ring terminals.

$ 249.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Performance Optimized Down Fire Sealed 10" Enclosure | JBL Club 102SL

$ 249.99

Enclosure Type Sealed

External Dimensions 30.00" W x 15.00" D x 5.26" H (measured in down fire position, excludes standoffs)

Gross Volume 0.65 cu ft

Net Volume 0.60 cu ft

Shipping Weight 36 lbs

Front Panel Thickness 1.5"

INSTALLER'S TAKE

Know what you are buying: the Club 102SL is a high-Q shallow 10, and no sealed box flattens it. At 0.60 cubic feet it reads Qtc 1.71 on the 4 ohm setting, a punchy bump near 60 Hz. That suits rock, rap and anything that lives in the upper bass; it is not a deep, flat SQ box.

Use the 4 ohm switch position unless you need the 2 ohm load; it is the tighter of the two in this box (Qtc 1.71 against 1.88).

Measure the installed height, not the cabinet height. The box is 5.26 tall on its own and the standoffs add 1.75, so plan around 7.01 inches of stack on the 30 by 15 footprint.

Floor slot is 0.92 times the cone area at the 1.75 standoff, under the 1.0 target, but a 6 mm Xmax woofer does not move enough air for that to matter much. Taller feet if your floor allows.

Inserts ship in the kit, not pressed: JBL prints no bolt circle. Mark from the driver, drill, press.

Product Details

Proline X Performance Optimized Down Fire 10" Sealed

Cut and tuned for the JBL Club 102SL

V-Groove and DadoLangboard Elite MDF0.60 cu ft NetStandoffs Included

0.60cu ft net

1.71system Qtc, 4 ohm

37.4 HzF3 rolloff, anechoic

5.26 incabinet height, excludes standoffs

Performance, Performance Optimized, and Micro

Proline X builds three tiers of Down Fire enclosure. The difference is not finish or materials, it is whether the cabinet was designed for a category or for a driver, and how much of the fitting work is already done for you.

	Performance	Performance Optimized	Micro Series
Fitment	Universal. Accepts any subwoofer that clears the published cutout and mounting depth.	Woofer specific. Cut for one named subwoofer, with cutout, mounting depth, magnet clearance and displacement drawn in CAD from that driver.	Woofer specific. Cut for one named subwoofer.
Footprint	Sized to the driver diameter.	A shared 30 by 15 inch platform, with cabinet height as the variable. This build sits on that platform at 5.26 inches tall, the height that holds 0.60 cubic feet.	Compact per driver footprint.
Front baffle	Single, 3/4 inch.	Double, 1.5 inch, outer layer machined as a flush recess.	Double, 1.5 inch.
Driver mounting	Solid flange. You drill your own mounting holes.	Threaded insert kit and stainless machine screws included; JBL prints no bolt circle, so you mark and drill from the driver.	Threaded inserts, stainless machine screws included.
Joinery	V-groove and dado, CNC cut.	V-groove and dado, CNC cut, perimeter cross brace.	Stack fab, dowel reinforced.
Published alignment	Modeled Qtc profiles across a range of drivers. No single response curve.	A real predicted Qtc and F3 for that exact driver, calculated from its own Thiele-Small parameters.	Target alignment described in the listing.
Carpet	Gray standard, black optional.	Plush black.	Plush black.
Warranty	1 year limited.	1 year limited.	2 years.

Feet ship with every tier, uninstalled on purpose. Mount them where your floor wants them for a down fire install, or leave them off and run the cabinet front firing or up firing. The orientation is yours to choose.

This page is a Performance Optimized enclosure. The airspace, the cutout and the cabinet height all come from the driver's own numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.

Built Around the JBL Club 102SL

Nothing about this cabinet is generic. The baffle is cut to JBL's 9.00 in (228.6 mm) cutout, and the 10.52 in (267.3 mm) frame covers it with margin. The airspace lands on 0.60 cubic feet net.

The Club 102SL is JBL's shallow-mount 10 inch: an aluminum cone on a rubber surround, a 2 inch voice coil, 350 watts RMS and 1050 watts peak, and just 3.25 inches of mounting depth on a 10.52 inch frame. On a down fire, where the motor rises into the cabinet, that shallow depth leaves plenty of room. See the JBL Club 102SL for the driver itself. Every figure comes from JBL's own Club 102SL owner's manual, which prints a separate parameter set for each position of the impedance switch. This cabinet is designed on the 4 ohm set; at 2 ohms the same box reads Qtc 1.88.

Net Volume, Not Gross

We build this cabinet at 0.60 cubic feet net, out of 0.65 gross after the brace. JBL publishes no driver displacement; an estimated 0.04 cubic feet is taken out of the net figure.

The Club 102SL is a high-Q woofer, Qts 1.10 at 4 ohms, and a sealed box can only raise system Q, never lower it below the driver's own. No sealed box of any size reaches the 0.707 of a flat alignment, so 0.60 cubic feet is chosen for the space: a little above JBL's own 0.53 cubic foot recommendation (Qtc 1.78) and inside its 0.42 to 0.69 range. At Qtc 1.71 the response rises about 5 dB to a peak near 60 Hz, returns to its reference level around 42 Hz and is 3 dB down at 37.4 Hz. Expect full, punchy upper bass rather than flat, deep extension.

True net, not marketing net. Internal volume is calculated from the machined cavity dimensions and the driver's displacement, not estimated from external dimensions minus wall thickness.

SSI Setting	System Qtc	fc	F3	Peak
4 ohm (design basis)	Qtc 1.712	54.6 Hz	37.4 Hz	+5.1 dB
2 ohm	Qtc 1.880	55.9 Hz	37.9 Hz	+5.8 dB

Down Fire Construction

Cut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3/4 inch MDF. Every panel joint is a machined interlocking groove that mechanically locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. Corners are square on Down Fire cabinets.

The cabinet measures 30.00 inches wide by 15.00 inches deep by 5.26 inches tall, measured in the down fire position and excluding standoffs. Plan the space around the installed height rather than the cabinet height: the standoffs hold 1.75 inches under the baffle, so the finished stack sits near 7.01 inches.

Double Baffle, Flush Recess

The front baffle is 1.5 inches, two bonded 3/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3/4 inch of internal clearance.

Side-Mounted Terminal Cup

Proline X ABS and carbon fiber composite cup with stainless hardware and copper ring terminals, pre-wired in 12 gauge OFC. Side mounted so it stays accessible with the baffle facing the floor.

Standoffs Included

JBL publishes no front clearance figure for the Club 102SL, so this cabinet uses the Proline X standard 1.75 inch standoff, shipped with every enclosure and left uninstalled so you can place them to suit your floor. At that height the floor slot is 0.92 times the cone area, under the 1.0 we aim for. With only 6 mm of excursion the cone moves about 208 cubic centimeters, so the smaller opening costs little, and taller feet or a front-firing install remove it.

Motor Clearance and Orientation

The motor rises off the baffle into the cavity, so on a down fire cabinet the clearance that matters runs to the top panel. The 3.25 inch mounting depth puts the motor 1.75 inches into a 3.01 inch cavity, leaving 1.26 inches above the motor against a 0.75 inch minimum. Height was set by the airspace, above the minimum the clearance alone would have required.

JBL does not publish a position on down firing this driver, and this cabinet makes no claim on their behalf. The feet ship uninstalled, so if you would rather run it front firing or up firing, that is a decision you can make at install time without changing anything about the enclosure.

Power, Mounting and Warranty

JBL rates the Club 102SL at 350 watts RMS and 1050 watts peak. The Club 102SL has one voice coil and JBL's Selectable Smart Impedance (SSI) switch, which sets it to 2 or 4 ohms without rewiring. The 4 ohm setting is the tighter alignment in this box; 2 ohms draws more power from a 2 ohm stable mono amplifier. Turn the amplifier off before switching. Confirm the load against your amplifier's minimum stable impedance before powering the system.

JBL prints no bolt circle for the Club 102SL, so the baffle ships undrilled with a threaded insert kit and stainless machine screws: set the driver in the recess, mark its holes, drill, press the inserts and bolt it down. The enclosure carries a 1 year limited warranty. Bring your own Club 102SL; the driver is sold separately.

Cut for the Driver, Not the Catalog

Built one at a time in Tullahoma, Tennessee, with standoffs and a 1 year limited warranty. Questions on fitment or amplifier matching, call 931-563-5151.

Specifications

Specification	Value
Series	Proline X Performance Optimized Down Fire
Compatible Driver	JBL Club 102SL, quantity 1. Direct fit
Configuration	Single 10 inch, sealed down fire
Mounting Position	Trunk or cargo floor, baffle facing down on standoffs
Firing Direction	Downward. Feet ship uninstalled, so front or up firing is also possible
External Width	30.00 in
External Depth	15.00 in
External Height	5.26 in in the down fire position, excludes standoffs
Installed Height	7.01 in including the 1.75 in standoff
Internal Volume, Gross	0.65 cu ft
Internal Volume, Net Acoustic	0.60 cu ft after the brace and an estimated 0.04 cu ft driver displacement
Height Set By	Airspace; clearance alone would allow a lower cabinet
Driver Mounting Depth	3.25 in required, 1.26 in clearance above the motor
Floor Slot	0.92 times the cone area at the 1.75 in standoff
Alignment, SSI 4 ohm	Qtc 1.712, fc 54.6 Hz, F3 37.4 Hz anechoic, peak +5.1 dB near 60 Hz
Alignment, SSI 2 ohm	Qtc 1.880, fc 55.9 Hz, F3 37.9 Hz anechoic, peak +5.8 dB
Volume Basis	0.60 cu ft per driver, inside JBL's 0.42 to 0.69 sealed range (JBL recommends 0.53). No sealed volume reaches Qtc 0.707 with this driver
Woofer Opening	9.00 in (228.6 mm), JBL spec
Frame Outer Diameter	10.52 in (267.3 mm), JBL spec
Bolt Circle	Not printed by JBL; threaded insert kit included
Driver Displacement	Not published by JBL; 0.04 cu ft estimated
Fs / Qts / Qes / Qms (4 ohm)	35 Hz / 1.097 / 1.329 / 6.263
Fs / Qts / Qes / Qms (2 ohm)	36.2 Hz / 1.218 / 1.401 / 9.325
Vas / Mms / Bl (4 ohm)	24.4 L / 144 g / 10.37 T-m
Driver Sd	346 cm2, JBL spec
Xmax	6 mm, JBL spec
Driver Sensitivity	81 dB at 1 W / 1 m, JBL manual
Driver Power Handling	350 W RMS / 1050 W peak
Impedance	Single voice coil, SSI switch-selectable 2 or 4 ohm
Parameter Source	JBL Club 102SL / 122SL owner's manual
Material	Langboard Elite MDF
Construction	CNC cut, V-groove and dado joinery, square corners
Panel Thickness	0.75 in
Front Baffle	1.5 in double baffle, outer layer machined as a flush recess
Internal Bracing	Windowed brace, dadoed to the shell
Driver Mounting	Threaded insert kit included, NOT pre-installed: JBL prints no bolt circle
Terminal Cups	One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC
Standoffs	Included, 1.75 in, shipped uninstalled
Damping	Light polyfill wall lining, does not alter acoustic volume
Carpet	Plush black
Shipping Weight	36 lb
Warranty	1 Year Limited, enclosure
Built In	Tullahoma, Tennessee

Performance Graphs

Net airspace

0.60

cu ft

System Qtc

1.71–1.88

sealed

Half power

37.4–37.9

Hz · F3

Xmax at

W RMS · no filter

With 25 Hz subsonic

W RMS · +0%

Amplifier

350

W RMS recommended

This enclosure holds 0.60 cu ft net . In it the JBL Club 102SL runs a system Qtc of 1.71–1.88 with half power at 37.4–37.9 Hz, and the cone reaches its 6.0 mm travel limit at 62 W, below the driver’s 350 W thermal rating, so travel is what stops you here, not heat. A 25 Hz subsonic filter adds little here: 63 W against 62 W, 0 percent. The box already resonates at 55–56 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 = 25.8–26.3

SSI switch at 4 ohm · EBP 26.3SSI switch at 2 ohm · EBP 25.8

EBP under 50 means a motor that wants a sealed load. The Club 102SL sits at 25.8–26.3, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

0.60 cu ft against a 24.4 L Vas.

α = Vas ÷ Vb = 1.44 · Fc = Fs√(α+1) = 55–56 Hz · Qtc = 1.71–1.88

SSI switch at 4 ohm · Qtc 1.71, Fc 55 Hz, F3 37.4 HzSSI switch at 2 ohm · Qtc 1.88, Fc 56 Hz, F3 37.9 Hz

The box lifts resonance from 35.0–36.2 Hz free-air to 55–56 Hz and half power lands at 37.4–37.9 Hz, anechoic, before any cabin gain. Figures are JBL’s own Club 102SL owner’s manual, which prints a separate parameter set for each position of the impedance switch. With a Qts of 1.10 at 4 ohms and 1.22 at 2 ohms this is a high-Q woofer: no sealed box of any size brings it down to Qtc 0.707, so 0.60 cubic feet is a volume chosen for the space, and the response carries a peak of about 5 dB near 60 Hz rather than a flat rolloff. The 4 ohm setting is the tighter of the two. The same 0.60 cubic feet as the wedge versions, on the 30 by 15 inch down fire platform.

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

P_Xmax = 62–68 W unfiltered → 63–69 W with a 25 Hz subsonic

SSI switch at 4 ohm · 68 W, no filterSSI switch at 2 ohm · 62 W, no filterSSI switch at 4 ohm · 69 W with subsonic at 25 Hz, 24 dB/octSSI switch at 2 ohm · 63 W with subsonic at 25 Hz, 24 dB/octXmax 6.0 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 6.0 mm. Unfiltered that is 62 W, reached first at 52 Hz. It sits under the 350 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: 63 W against 62 W. At 55–56 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.

Param	Value	Unit	Note
Fs	35.00 / 36.20	Hz	free-air resonance
Qts	1.097 / 1.218		SSI switch at 4 ohm / SSI switch at 2 ohm
Vas	24.38 / 23.49	L	equivalent compliance
Sd	346.4	cm²	effective piston area
Xmax	6	mm	one-way linear travel
Pe	350	W	continuous RMS
SPL	80.8	dB	1 W / 1 m, derived from T/S

Driver parameters as published by JBL Club 102SL owner's manual. Curves computed against this enclosure’s actual net airspace.

Materials

Material

Built From a Spec Sheet, Not a Sales Sheet

Every Proline X Performance Series enclosure is CNC-cut from Langboard Elite MDF, 3/4" (18mm) panels produced to published mill specifications. Most enclosure manufacturers source generic MDF without published data. We can tell you the internal bond rating, the modulus of elasticity, the modulus of rupture, and the face and edge screw holding strength for every panel in this enclosure, because we chose the material based on those numbers, not on price or availability.

Langboard Elite is produced in the United States. The specifications below are pulled directly from Langboard's published mill data and are verifiable. This is the same panel stock used in our full Proline X lineup.

Specifications

Langboard Elite MDF: Published Mill Data

Property	Value	Why It Matters
Panel Stock	Langboard Elite MDF	Named, verifiable panel source, not generic "high-density MDF"
Thickness	3/4" (18mm)	Industry standard for subwoofer enclosures; panels below this flex under pressure
Density	48.5 lbs/ft³	Higher density = less porosity, better screw retention, reduced resonance
Internal Bond	200 psi	Measures resistance to delamination under sustained internal pressure. The most enclosure-relevant spec on this sheet
Modulus of Rupture (MOR)	4,200 psi	Bending strength before the panel breaks, relevant for larger unsupported baffle spans
Modulus of Elasticity (MOE)	410,000 psi	Stiffness under load; higher MOE means less panel flex under bass pressure, less resonance
Face Screw Holding	325 lbs	How firmly the panel surface holds a screw; critical for baffle joint integrity over time
Edge Screw Holding	250 lbs	Panel edge retention, relevant for every joint that isn't face-to-face

Internal Bond

200 psi: The Number That Actually Matters for Enclosures

The internal bond rating measures how well the MDF panel resists delamination under sustained pressure applied perpendicular to the face. In a subwoofer enclosure, every bass transient generates a pressure pulse that pushes outward on every panel simultaneously. A panel that begins to delaminate internally loses stiffness gradually. The symptoms are slow: a box that starts to sound softer, less defined, less punchy over months of use. 200 psi internal bond is the spec that determines how long this enclosure holds its acoustic integrity under daily use at real power levels.

Stiffness

410,000 psi MOE: Less Flex, Less Resonance

The modulus of elasticity measures panel stiffness, its resistance to bending under load. A stiffer panel flexes less under the pressure generated by a high-excursion driver at volume. Panel flex is a source of acoustic coloration: the panel itself begins to radiate sound at its own resonant frequency, adding distortion to the output. 410,000 psi stiffness combined with V-groove and dado joinery means the panels stay rigid and the bracing controls resonance at the structure level, not the panel level. The bass you hear comes from the driver, not the box.

Screw Holding

325 lb Face / 250 lb Edge: Joints That Stay Locked

Screw holding strength determines how firmly the panel grips a fastener at the face and at the edge. This matters most at the baffle joint, where the front panel meets the side panels and where the driver is mounted. A panel with low screw holding strength allows fasteners to loosen over time under vibration, leading to air gaps at the joint and loss of acoustic seal. 325 lb face screw holding strength means the baffle hardware stays put. Combined with dado joinery and adhesive, the front panel on a Proline X Performance Series enclosure is not going anywhere.

Sourcing

Named Panel Stock: Not "Premium MDF"

The phrase "premium MDF" or "high-density MDF" appears on marketing copy for enclosures across every price point, from $40 to $400. It is not a specification. It is a description with no defined standard. Langboard Elite is a named, sourced, mill-documented product with published data. We name it in our copy because naming it holds us accountable to the spec. You can look up Langboard Elite independently, verify the numbers on this page, and confirm you are getting what we say you are getting. That is the point.

Why Proline X?

Most enclosures are built to a price point. Proline X is built to a spec. Every box starts with published-data MDF, gets CNC-cut to exact internal volume, and is assembled by hand in our Tennessee facility. The difference shows up in the measurements, and in how the box holds up two years into daily use.

CNC-Cut to Spec

Panels are machine-cut on ShopSabre CNC routers and joined with V-groove and dado joinery. Consistent geometry, no hand-cut variance, no gaps at the joints.