Proline X PO 12-S DF SC sealed down fire enclosure, front panel on 1.75 inch feet, 30 by 10.4 inches.

Proline X PO 12-S DF SC sealed down fire enclosure, end panel with recessed terminal cup, 15 by 10.4 inches.

Proline X

Performance Optimized Down Fire Sealed 12" Enclosure | Morel Ultimo Ti SC122 / SC124

Q: Does this fit both the SC122 and the SC124, and will any other 12 inch fit?

Both, yes. The 2 ohm SC122 and the 4 ohm SC124 share one basket, one 10.35 inch cutout, one 12.00 inch frame and one 5.96 inch mounting depth, so the fit is identical and the inserts are pressed for both. Any other 12, no. The airspace is engineered around the SC122's 0.45 Qts and 68.9 liters of Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

Q: Why 1.66 cubic feet, and what alignment does it target?

It is the Butterworth volume for the SC122, computed from Morel's published Fs 27.51 Hz, Qts 0.45 and Vas 68.86 liters: system Qtc 0.707, maximally flat, with resonance at 43.2 Hz and an anechoic half-power point of 43.2 Hz. Morel's own sealed recommendation for this driver is 20 to 50 liters, 0.71 to 1.76 cubic feet, and 1.66 cubic feet sits inside it.The 4 ohm SC124 has its own parameter set, Fs 28.00 Hz, Qts 0.41 and Vas 60.29 liters, and in the same cabinet it lands at Qtc 0.620 with F3 at 49.1 Hz, a touch more damped. One cabinet serves both coils because the box is sized to the coil that asks for the larger volume.

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

Morel rates the Ultimo Titanium SC at 600 watts RMS, so target 420 to 600 watts RMS at the final impedance. Both coils are single voice coil drivers: the SC122 is a nominal 2 ohm load at 1.3 ohms DC, the SC124 a nominal 4 ohm load at 3.0 ohms DC.A 2 ohm load from the SC122 is within most monoblocks' rating, but confirm your amplifier's minimum stable impedance before you buy that coil; the 4 ohm SC124 is the safe answer on any amplifier.

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

The cabinet is 10.44 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 12.19 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 subwoofer pushes as hard against its mounting surface as it does against the air, and a single 3/4 inch panel flexes under that load, which smears output and works the driver loose over time.The outer layer is machined as a flush recess to Morel's 12.00 inch frame, so the driver bolts to the inner layer through pressed threaded inserts.

Q: What is the expected low-frequency extension?

Anechoic F3 is 43.2 Hz for the SC122 and 49.1 Hz for the SC124, with system resonance at 43.2 and 42.3 Hz. At Qtc 0.71 the response is maximally flat into the rolloff, so F3 and fc coincide for the SC122.Those figures 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 numbers above. Morel's own sheet publishes no in-box F3 for this driver.

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 1.66 cubic feet this cabinet was built to.

Q: Is the driver included? What do I get?

No driver. This is an enclosure only. You receive the cabinet finished in plush black carpet, threaded inserts pressed to the Morel bolt pattern, stainless machine screws, one side-mounted pre-wired terminal cup, the standoffs and the polyfill lining already in place.The Morel Ultimo Ti SC122 / SC124 is purchased separately. The cabinet is cut direct fit to that driver, so it is not a general purpose 12 inch box.

SKU: PO 12-S DF SC

QUICK SPECS

Alignment: 1.66 cu ft net. SC122 Qtc 0.707, F3 43.2 Hz; SC124 Qtc 0.620, F3 49.1 Hz
Driver: SC122 (2 ohm) or SC124 (4 ohm), 600 W RMS, 9.5 mm Xmax, 5.96 in mounting depth
Standoffs: Included, 1.75 in, shipped uninstalled. Installed height near 12.19 in
Cabinet: 30.00"W x 15.00"D x 10.44"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.

$ 299.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Performance Optimized Down Fire Sealed 12" Enclosure | Morel Ultimo Ti SC122 / SC124

$ 299.99

Enclosure Type Sealed

External Dimensions 30.00" W x 15.00" D x 10.44" H (measured in down fire position, excludes standoffs)

Gross Volume 1.76 cu ft

Net Volume 1.66 cu ft

Weight 39 lbs

Front Panel Thickness 1.5"

INSTALLER'S TAKE

Measure the installed height, not the cabinet height. The box is 10.44 tall on its own and the standoffs add 1.75, so plan around 12.19 inches of stack on the 30 by 15 footprint.

Airspace set the height here, 1.66 cubic feet at the SC122's Butterworth volume; the 4 ohm SC124 rides along at Qtc 0.62.

Morel's spec sheet and Morel's 2016 manual disagree on this driver. The sheet's numbers reproduce their own moving mass and land inside Morel's recommended volumes; the manual's do not, so the sheet is what this cabinet is built to. Say so if a customer brings the manual.

Polyfill is already in as a wall lining. Adding more makes the box act larger and walks the alignment off the Butterworth volume.

Product Details

Proline X Performance Optimized Down Fire 12" Sealed

Cut and tuned for the Morel Ultimo Ti SC122 / SC124

V-Groove and DadoLangboard Elite MDF1.66 cu ft NetStandoffs Included

1.66cu ft net

0.71 / 0.62system Qtc, SC122 / SC124

43.2 HzF3 rolloff, SC122, anechoic

10.44 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 10.44 inches tall, the height that holds 1.66 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 inserts pressed to the Morel bolt pattern, stainless machine screws included.	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 Morel Ultimo Ti SC122 / SC124

Nothing about this cabinet is generic. The baffle is bored to the Ultimo Titanium SC 12's 10.35 inch cutout, 263 mm to Morel's sheet, and the airspace lands on 1.66 cubic feet net, the Butterworth volume for the SC122.

The Ultimo Titanium SC is Morel's 12 inch on a titanium voice coil former and a 5.1 inch Hexatech aluminium coil, rated 600 watts RMS and 2000 watts transient, 5.96 inches deep on a 12.00 inch frame, 9.5 mm of excursion each way. It ships as the SC122 (2 ohm) and the SC124 (4 ohm), and morel measures the two coils separately and publishes a different parameter set for each: the SC122 (2 ohm) at Fs 27.5 Hz, Qts 0.45 and Vas 68.9 liters, the SC124 (4 ohm) at Fs 28.0 Hz, Qts 0.41 and Vas 60.3 liters. The cabinet is sized to the SC122, the coil that asks for the larger box, and the SC124 sits a little below Butterworth in the same airspace.

Net Volume, Not Gross

We build this cabinet at 1.66 cubic feet net, out of 1.76 gross after the brace and Morel's published 2.6 liter driver displacement. Morel's own sealed recommendation for this driver is 20 to 50 liters, 0.71 to 1.76 cubic feet, and this volume is inside it. At 1.66 cubic feet the SC122 lands at Qtc 0.707 with system resonance at 43.2 Hz and an anechoic half-power point of 43.2 Hz; the SC124 sits at Qtc 0.620.

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

Coil	System Qtc	fc	F3
SC122, 2 ohm (cabinet sized to this coil)	Qtc 0.707	43.2 Hz	43.2 Hz
SC124, 4 ohm	Qtc 0.620	42.3 Hz	49.1 Hz

Two coils, two parameter sets. Every figure comes from Morel's current Ultimo Titanium SC specification sheet, whose columns reproduce their own moving mass from Vas, cone area and resonance to within a gram. Morel's older printed manual carries a different parameter set for these drivers that does not, and it is not used here.

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 10.44 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 12.19 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

Morel publishes no front clearance figure for the Ultimo Titanium SC, 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.

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 5.96 inch mounting depth puts the motor 4.46 inches into a 8.19 inch cavity, leaving 3.72 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.

Morel 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 and Warranty

Morel rates the Ultimo Titanium SC at 600 watts RMS and 2000 watts transient. Both coils are single voice coil drivers: the SC122 is a nominal 2 ohm load (1.3 ohm DC), the SC124 a nominal 4 ohm load (3.0 ohm DC). Confirm the load against your amplifier's minimum stable impedance before powering the system.

The enclosure carries a 1 year limited warranty. Bring your own Morel Ultimo Ti SC122 / SC124; the driver is purchased 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	Morel Ultimo Titanium SC, SC122 or SC124, quantity 1. Direct fit
Configuration	Single 12 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	10.44 in in the down fire position, excludes standoffs
Installed Height	12.19 in including the 1.75 in standoff
Internal Volume, Gross	1.76 cu ft
Internal Volume, Net Acoustic	1.66 cu ft after the brace and Morel's published 2.6 L displacement
Height Set By	Airspace; clearance alone would allow a lower cabinet
Driver Mounting Depth	5.96 in required, 3.72 in clearance above the motor
Morel Published Sealed Range	20 to 50 liters, 0.71 to 1.76 cubic feet, including driver displacement
Alignment, SC122 (2 ohm)	Qtc 0.707, fc 43.2 Hz, F3 43.2 Hz anechoic; the cabinet is sized to this coil
Alignment, SC124 (4 ohm)	Qtc 0.620, fc 42.3 Hz, F3 49.1 Hz anechoic, in the same cabinet
Woofer Opening	10.35 in (263 mm) direct fit
Frame Outer Diameter	12.00 in (305 mm), Morel spec
Bolt Circle	11.50 in (292 mm), Morel drawing; inserts pressed to it
Driver Displacement	2.6 L / 0.09 cu ft, published by Morel
SC122 Fs / Qts / Qes / Qms	27.51 Hz / 0.45 / 0.59 / 2.05
SC122 Vas / Mms / Cms / BL	68.86 L / 136.0 g / 0.245 mm/N / 7.19 T-m
SC124 Fs / Qts / Qes / Qms	28.00 Hz / 0.41 / 0.50 / 2.14
SC124 Vas / Mms / Cms / BL	60.29 L / 150.0 g / 0.215 mm/N / 12.27 T-m
Driver Sd	448 cm2, published by Morel
Xmax	9.5 mm one way, published as plus or minus 9.5 mm each way; 12 mm gap
DC Resistance	SC122 1.3 ohm; SC124 3.0 ohm
Driver Sensitivity	89 dB at 2.83 V for both coils, Morel spec; 85.7 and 86.1 dB at 1 W derived from the parameters
Driver Power Handling	600 W RMS / 2000 W transient
Wiring Options	Single voice coil: SC122 nominal 2 ohm, SC124 nominal 4 ohm
Voice Coil	130 mm (5.1 in) Hexatech aluminium on a titanium former, 31 mm winding height
Parameter Source	Morel Ultimo Titanium SC specification sheet; Morel's 2016 manual prints a different set that is not used
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 Hardware	Threaded inserts pressed to the Morel bolt pattern, stainless machine screws included
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
Weight	39 lb
Warranty	1 Year Limited
Built In	Tullahoma, Tennessee

Performance Graphs

Net airspace

1.66

cu ft

System Qtc

0.62–0.71

sealed

Half power

43.2–49.1

Hz · F3

Xmax at

117

W RMS · no filter

With 25 Hz subsonic

173

W RMS · +48%

Amplifier

600

W RMS recommended

This enclosure holds 1.66 cu ft net . In it the Morel Ultimo Ti SC122 / SC124 runs a system Qtc of 0.62–0.71 with half power at 43.2–49.1 Hz, and the cone reaches its 9.5 mm travel limit at 117 W, below the driver’s 600 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 173 W — +56 W, or 48 percent more power for the same 9.5 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 46.6–56.0

SC122, 2 ohm · EBP 46.6SC124, 4 ohm · EBP 56.0

The Ti SC 12 straddles the boundary at 46.6–56.0 depending on coil — part sealed-band, part transition. Either way it takes a sealed load happily; the coil you run shifts the alignment more than it shifts this verdict.

02What the box does to it

1.66 cu ft against a 68.9 L Vas.

α = Vas ÷ Vb = 1.47 · Fc = Fs√(α+1) = 42–43 Hz · Qtc = 0.62–0.71

SC122, 2 ohm · Qtc 0.71, Fc 43 Hz, F3 43.2 HzSC124, 4 ohm · Qtc 0.62, Fc 42 Hz, F3 49.1 Hz

The box lifts resonance from 27.5–28.0 Hz free-air to 42–43 Hz and half power lands at 43.2–49.1 Hz, anechoic, before any cabin gain. Morel measures the 2 ohm and 4 ohm coils separately and publishes a different resonance and compliance for each, so both are plotted rather than averaged; the cabinet is sized to the coil that asks for the larger box and the other coil sits a little below Butterworth in it. Figures are from Morel’s current specification sheet; Morel’s 2016 manual prints a different parameter set that does not reproduce its own moving mass and is not used here. This down-fire holds 1.66 cubic feet, the Butterworth volume for the SC122 and the top of Morel’s own 0.71 to 1.76 cubic foot sealed range; it is the wedge single’s airspace in a floor-firing shape.

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

P_Xmax = 117–122 W unfiltered → 173–187 W with a 25 Hz subsonic

SC122, 2 ohm · 122 W, no filterSC124, 4 ohm · 117 W, no filterSC122, 2 ohm · 173 W with subsonic at 25 Hz, 24 dB/octSC124, 4 ohm · 187 W with subsonic at 25 Hz, 24 dB/octXmax 9.5 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 9.5 mm. Unfiltered that is 117 W, reached first at 20 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: stopping the cone wasting travel below the passband lets it take 173 W before hitting the same 9.5 mm. That is 48 percent more amplifier for the price of one filter setting.

Param	Value	Unit	Note
Fs	27.51 / 28.00	Hz	free-air resonance
Qts	0.450 / 0.410		SC122, 2 ohm / SC124, 4 ohm
Vas	68.86 / 60.29	L	equivalent compliance
Sd	448.0	cm²	effective piston area
Xmax	9.5	mm	one-way, Morel prints it as plus or minus 9.5 mm each way
Pe	600	W	continuous RMS
SPL	85.7	dB	1 W / 1 m, derived from T/S

Driver parameters as published by Morel Ultimo Titanium SC specification sheet, morelhifi.com. 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.