

Performance Optimized · Datasheet
Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure Morel Ultimo PowerSlim PS104D · Dual 10" Sealed enclosure
- Net volume
- 0.502 cu ft after displacement
- Max mounting depth
- 3.1 in / 79.6mm, Morel spec
- External dimensions
- 41 in W × 7.0625 in in the down fire position H × 12 in D
- Front baffle
- 1.5 in double baffle at both positions, outer layer machined as a flush recess
- Alignment: 0.502 cu ft net per chamber, 1.004 total. Qtc 1.163, Fc 48.3 Hz, F3 35.9 Hz per driver
- Down Fire Wide: 41"W x 12"D x 7.0625"H in down fire position, 3" shallower and 11" longer than the standard 30 x 15, for under rear seats and narrow cargo floors
- Drivers: Pair of Morel PS104D (DVC 4 ohm), 700W RMS each / 1400W combined, 11mm Xmax each way, 3.1" mounting depth
- Chambers: Two fully separate sealed chambers, 3/4" MDF full divider, one shared side-mounted terminal cup
- Feet: 1.75", ship uninstalled. Installed height 8.8125"
Spec of record
Technical specifications
| Series | Proline X Performance Optimized Down Fire Wide |
|---|---|
| Compatible Driver | Morel Ultimo PowerSlim PS104D (DVC 4 ohm), pair required. Direct fit |
| Enclosure Type | Sealed, dual driver, down fire, floor coupled |
| Intended Fitment | Under the rear seat of trucks and SUVs and narrow cargo floors, where depth is the limiting dimension |
| Firing Direction | Down firing, both drivers fire toward the floor. Feet ship uninstalled, so front or up firing is also possible |
| Chamber Configuration | Two fully separate chambers, full divider, single shared side-mounted terminal cup |
| External Width | 41 in |
| External Depth | 12 in |
| External Height | 7.0625 in in the down fire position, excludes feet |
| Installed Height | 8.8125 in with the 1.75 in feet |
| Standard 30 x 15 Equivalent | 30 x 15 x 7.6875 in, 0.50 cu ft net per chamber. Same driver, deeper and shorter footprint |
| Internal Volume, Gross | 1.126 cu ft total |
| Net Volume Per Chamber | 0.502 cu ft after displacement |
| Total Net Volume | 1.004 cu ft |
| Height Set By | Airspace; motor clearance allows a lower cabinet |
| Clearance Above Motor | 3.21 in |
| Alignment Per Chamber | Qtc 1.163, Fc 48.3 Hz, F3 35.9 Hz anechoic |
| Woofer Opening | 9.1 in / 231.5mm, Morel spec |
| Mounting Depth Required | 3.1 in / 79.6mm, Morel spec |
| Driver Overall Diameter | 10.35 in / 263mm, Morel spec |
| Driver Fs | 29.1 Hz |
| Driver Qts | 0.7; Qtc cannot fall below this in any sealed box |
| Driver Qes / Qms | 0.9 / 3.6 |
| Driver Vas | 25 L |
| Driver Mms / BL | 203 g / 8.1 |
| Driver Sd | 346.4 cm2 |
| Driver Xmax | 11mm each way |
| Driver Sensitivity | 82 dB (2.83V/1m) |
| Driver Voice Coil | 129.5mm / 5.1 in, four layers carbon, aluminium former |
| Driver Motor | Double magnet EVC |
| Driver Cone | Flat honeycomb Hexatech aluminium |
| Morel Sealed Recommendation | 12.7 liters per driver |
| Power Handling | 700 W RMS / 1800 W max transient each, 1400 W RMS combined |
| Recommended Power Per Driver | 350 to 700 W RMS, Morel rated range |
| Voice Coil Configuration | Dual 4 ohm per driver, final impedance set at the drivers |
| Driver Displacement | 0.05 cu ft each, estimated; Morel publishes none |
| Material | Langboard Elite MDF |
| Construction | CNC cut on ShopSabre routers, V-groove and dado joinery |
| Panel Thickness | 0.75 in |
| Front Baffle | 1.5 in double baffle at both positions, outer layer machined as a flush recess |
| Internal Bracing | Full-height 3/4 in bonded divider |
| Corner Profile | Square, Down Fire series standard |
| Driver Mounting | 8/32 threaded inserts, stainless machine screws included, 2 sets |
| Terminal Cup | One Proline X ABS and carbon fiber composite, side mounted |
| Internal Wiring | 12 gauge OFC to both driver positions in parallel |
| Feet | Included, 1.75 in, shipped uninstalled |
| Damping | Polyfill pre-installed as a light wall lining per chamber |
| Carpet | Plush Black |
| Bundle Options | Enclosure only, bring your own pair of Morel PS104D |
| Warranty | 1 Year Limited |
| Built In | Tullahoma, Tennessee |
Modelled response
Performance in this enclosure
01Is it a sealed driver?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
0.502 cu ft against a 25.0 L Vas.
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.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 29.10 | Hz | free-air resonance |
| Qts | 0.700 | D4 | |
| Vas | 25.00 | L | equivalent compliance |
| Sd | 346.4 | cm² | effective piston area |
| Xmax | 11 | mm | one-way linear travel |
| Pe | 700 | W | continuous RMS |
| SPL | 80.2 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by Morel Ultimo PowerSlim owner's manual, rev 24-12-23. Curves computed against this enclosure’s actual net airspace.
From the shop floor
Installer's take
1400 watts RMS combined in a cabinet 12 inches deep and 7.0625 inches tall. It comes from a pair of drivers that each mount in 3.1 inches.
Each PS104D runs a 5.1 inch voice coil wound in four layers of carbon. Most shallow 10s use a 2 to 2.5 inch coil. That surface area is why these take 700 watts apiece continuously.
Each chamber holds 0.502 cubic feet net, which is Morel's 12.7 liter recommendation. Qtc lands at 1.163 with F3 at 35.9 Hz. That is above unity and it is meant to be: Qts is 0.7, so a flat alignment is not on the table in any sealed box. Morel publishes no displacement for this driver, so the 0.05 cubic feet we subtract is our estimate.
Separate chambers, full-height bonded divider, one shared side-mounted cup. Dual 4 ohm coils on each driver, so set impedance at the drivers and wire both the same.
Before you order
Questions
Why is this cabinet 41 inches wide instead of 30?
Because it is only 12 inches deep. The standard Performance Optimized Down Fire platform is 30 wide by 15 deep, and under a rear seat or on a narrow cargo floor there is often not 15 inches to give.
The airspace lost from the depth is recovered from the length, so the cabinet runs 41 inches instead of 30 and stands 7.0625 inches tall, with each driver in its own separate chamber. If you do have 15 inches of depth, the standard 30 by 15 cabinet is the better pick.
How does this compare to the standard 30 x 15 dual PowerSlim PS104D enclosure?
The standard cabinet is 30 by 15 by 7.6875 inches and gives each driver 0.50 cubic feet net. This one is 41 by 12 by 7.0625 inches and gives each driver 0.502 cubic feet net. The height was solved to hold the same airspace as the standard box, so the alignment carries over.
The choice is about shape: the standard box if you have 15 inches of depth, this one when depth is the limit and you have 41 inches of run.
Why is the Qtc above 1.0?
Because the PS104D has a free-air Qts of 0.7, so system Qtc cannot fall below 0.7 in any sealed box, and in Morel's own recommended volume it lands higher. At 0.502 cubic feet net per chamber each driver runs Qtc 1.163 with Fc at 48.3 Hz and a predicted F3 of 35.9 Hz.
That means a lift near the corner frequency, more weight and impact, less of a flat anechoic curve. It is the driver's intended voicing, not a consequence of the wide footprint.
How is this enclosure wired, and how do I set my final impedance?
One side-mounted Proline X terminal cup with a single pair of posts is pre-wired in 12 gauge OFC to both driver positions in parallel. Each PS104D has dual 4 ohm coils, so the way you wire the coils on each driver sets the load the amplifier sees. Wire both drivers identically and confirm the resulting load against your amplifier's minimum stable impedance. Target 350 to 700 watts RMS per driver.
Where is the terminal cup located on a down fire enclosure?
Side mounted, and there is one cup serving both chambers. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup, and on a down fire cabinet that keeps the connection accessible with the enclosure in its installed position, since both baffles face the floor. The cup is our Proline X ABS and carbon fiber composite unit, recessed, with stainless hardware, copper ring terminals and pre-wired 12 gauge OFC to both driver positions in parallel.
How is this enclosure built?
V-groove and dado joinery, CNC cut on ShopSabre routers from Langboard Elite MDF, so every panel joint locks mechanically before adhesive is applied. The front baffle is a 1.5 inch double layer with the outer layer machined as a flush recess, and each driver lands on 8/32 threaded inserts with stainless machine screws. A full-height bonded 3/4 inch divider separates the two chambers and ties the walls together across the 41 inch span. Corners are square, the Down Fire series standard, which keeps the most internal volume for the footprint. Assembled and inspected in Tullahoma, Tennessee.
Do I need to add polyfill or damping?
No. Polyfill is already installed as a light wall lining in each 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 walks the alignment away from the 0.502 cubic feet per chamber this cabinet was built to.
Are the Morel PS104D subwoofers included with this enclosure?
No. This listing is for the enclosure only. Bring your own pair of Morel Ultimo PowerSlim PS104D; the drivers are purchased separately. The cutout and mounting depth are direct fit at both positions, and the 1.75 inch feet ship uninstalled for an installed height of 8.8125 inches.
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