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

Performance Optimized · Datasheet

Performance Optimized Wedge Wide Sealed Triple 12" Enclosure Morel Ultimo SCX122 · Triple 12" Sealed enclosure

Net volume
1.942 cu ft per driver, 5.83 cu ft total, after both dividers and an estimated 0.080 cu ft displacement per driver
Max mounting depth
5.57 in required; 10.94 in clearance above the motor against the raked rear panel
External dimensions
44 in W × 17 in at the seat face H × 23.00 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
Morel Ultimo SCX122Buy at Audio Intensity
  • Best For: Triple Morel Ultimo SCX122 SUV Cargo-Floor Builds
  • Net Volume: 1.942 cu ft per Driver (5.83 cu ft Net Total)
  • Driver Match: Three Morel Ultimo SCX122 (matched set), 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 DriverMorel Ultimo SCX122, 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 Depth23.00 in at the base, tapering to 16.81 in at the top
Internal Volume, Gross6.29 cu ft total
Internal Volume, Net Acoustic1.942 cu ft per driver, 5.83 cu ft total, after both dividers and an estimated 0.080 cu ft displacement per driver
Driver Mounting Depth5.57 in required; 10.94 in clearance above the motor against the raked rear panel
Alignment Per DriverUltimo SCX122 Qtc 0.934, fc 42.9 Hz, F3 34.8 Hz anechoic
Woofer Openings3 at 10.400 in
Woofer LayoutOne row across the face
Frame Outer Diameter12 in
Fs / Qts / Qes / Qms32.1 Hz / 0.700 / 1.030 / 2.130
Vas / Sd / Xmax43.0 L / 430 cm2 / 9 mm
Driver Power Handling500 W RMS per driver, 1500 W RMS for the set of 3 (thermal rating)
Recommended Amplifier100-150 W RMS per driver, 300-450 W RMS for the full set
Parameter SourceMorel 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 Weight101 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.942
cu ft per driver
System Qtc
0.93
sealed
Half power
34.8
Hz · F3
Xmax at
134
W RMS per driver · no filter
With 25 Hz subsonic
153
W RMS per driver · +14%
Amplifier, per driver
100–150
W RMS recommended
This enclosure holds 1.942 cu ft net per driver. In it the Morel Ultimo SCX122 runs a system Qtc of 0.93 with half power at 34.8 Hz, and the cone reaches its 9.0 mm travel limit at 134 W per driver, below the driver’s 500 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 153 W per driver — +19 W, or 14 percent more power for the same 9.0 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 100–150 W RMS  ×  3 drivers  =  full set 300–450 W RMS
Look for a mono amplifier rated 300–450 W RMS at the load your coil version wires to. Travel sets the top here, not heat: past 153 W per driver the cone runs beyond Xmax even with the subsonic set, under the driver’s 500 W thermal rating. The top of the range needs the 25 Hz subsonic filter set; without it, keep each driver under 134 W, where the cone reaches Xmax unfiltered. 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 = 31.2
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 Ultimo SCX122 31.2
Ultimo SCX122 · EBP 31.2
EBP under 50 means a motor that wants a sealed load. The Ultimo SCX122 sits at 31.2, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

1.942 cu ft against a 43.0 L Vas.

α = Vas ÷ Vb = 0.78  ·  Fc = Fs√(α+1) = 43 Hz  ·  Qtc = 0.93
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
Ultimo SCX122 · Qtc 0.93, Fc 43 Hz, F3 34.8 Hz
The box lifts resonance from 32.1 Hz free-air to 43 Hz and half power lands at 34.8 Hz, anechoic, before any cabin gain. Figures are Morel’s published parameters; Qes and Qms reproduce the printed Qts. This cabinet holds three drivers in three separate sealed chambers of 1.942 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 9.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 134 W per driver unfiltered  →  153 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 9.0 mm 134 W reaches Xmax here
Ultimo SCX122 · 134 W, no filterUltimo SCX122 · 153 W with subsonic at 25 Hz, 24 dB/octXmax 9.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 9.0 mm. Unfiltered that is 134 W per driver, reached first at 28 Hz. It sits under the 500 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 153 W per driver before hitting the same 9.0 mm. That is 14 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs32.10Hzfree-air resonance
Qts0.700Ultimo SCX122
Vas43.00Lequivalent compliance
Sd430.0cm²effective piston area
Xmax9mmone-way linear travel
Pe500Wcontinuous RMS
SPL83.3dB1 W / 1 m, derived from T/S

Driver parameters as published by Morel Ultimo SCX122 published specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Start with the size. 1.942 cubic feet per driver puts the Ultimo SCX122 at Qtc 0.934, resonance 42.9 Hz, half power 34.8 Hz anechoic. Maximally flat on these figures would need 75.55 cubic feet per driver. The wide platform stops at 23 inches deep, so this box lands a little above flat: a small lift near resonance and firm midbass.

Measure the base depth, not the top. This cabinet is 23.00 in deep where it meets the floor, 16.81 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.

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: 100 to 150 W RMS per driver is 300 to 450 W RMS across all 3. On this driver travel sets the top, not heat: Xmax arrives at 153 W per driver with a 25 Hz subsonic, under the 500 W rating. Set the 25 Hz subsonic to use the top of that range; without it keep each driver under 134 W.

Morel's Qes and Qms reproduce the printed Qts within 3 percent, so the alignment rests on a self-consistent set. Morel do not publish driver displacement; we deduct an estimated 0.080 per driver, so true net can sit a few hundredths either way.

Polyfill is in as a wall lining in every chamber. Do not add more: it makes the box act larger and walks Qtc off 0.93.

Before you order

Questions

Does this fit the Morel Ultimo SCX122, and its coil versions?

Yes. Each opening is cut to 10.400 in for the 12 in frame, and the 5.57 in deep motor clears the raked rear panel with 10.94 in to spare. Coil versions of the Morel Ultimo SCX122 share the frame, cutout and mounting depth, so any of them drops in. The alignment on this page is computed on the Ultimo SCX122 parameters.

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

Why 1.942 cubic feet per driver, and what alignment does it target?

On Morel's published Fs 32.1 Hz, Qts 0.700 and Vas 43.0 liters, 1.942 cubic feet per driver gives Qtc 0.934, system resonance 42.9 Hz and half power 34.8 Hz.

Maximally flat on these figures would need 75.55 cubic feet per driver. The wide platform stops at 23 inches deep, so this box lands a little above flat: a small lift near resonance and firm midbass.

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

Morel rates the Ultimo SCX122 at 500 watts RMS per driver. Recommended amplifier: 100 to 150 W RMS per driver, 300 to 450 W RMS for the full set of 3. Travel, not heat, sets the top: the cone reaches Xmax at 153 W per driver with a 25 Hz subsonic set, under the 500 W rating. The top of that range needs the 25 Hz subsonic; without it keep each driver under 134 W.

Loads depend on the coil version you run. Three dual 4 ohm drivers, coils in series, all three in parallel: 2.67 ohms; coils in parallel, all three in series: 6 ohms. Dual 2 ohm: 1.33 ohms or 3 ohms the same two ways. Single 4 ohm: 1.33 ohms in parallel, 12 ohms in series. Use the lower load only on an amplifier rated stable there.

Will it fit my SUV?

It is 44 inches wide, 17 tall and 23.00 deep at the base, tapering to 16.81 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 34.8 Hz per driver with system resonance at 42.9 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 1.942 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 Morel Ultimo SCX122 drivers. The cabinet is cut direct fit to them, not a general purpose 12 inch box.

Same series, same size

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