

Performance Optimized · Datasheet
Performance Optimized Down Fire Wide Sealed 12" Shallow Sub Enclosure Arc Audio SW12 · Single 12" Sealed enclosure
- Net volume
- 0.752 cu ft after displacement and the brace
- Max mounting depth
- 2.4 in
- External dimensions
- 41 in W × 5.125 in in the down fire position H × 14 in D
- Front baffle
- 1.5 in double baffle, outer layer machined as a flush recess
- Alignment: 0.752 cu ft net. Coils in series: Qtc 1.001, Fc 53.1 Hz, F3 41.7 Hz; Coils in parallel: Qtc 0.990, Fc 53.1 Hz, F3 41.9 Hz
- Down Fire Wide: 41"W x 14"D x 5.125"H in down fire position, excludes the 1.75" standoffs (installed height 6.875"). Stands lower than the standard 30 x 15 at 6"
- Height set by: airspace; 1.98" of clearance above the motor
- Driver: Arc Audio SW12 (DVC 2 ohm or 4 ohm), 400W RMS / 800W peak, 2.4" mounting depth or 2.23" front loaded, 11" cutout
- Build: Langboard Elite MDF, V-groove and dado, 1.5" double baffle with flush outer recess, windowed U-brace, 12g OFC side-mounted terminal cup
Spec of record
Technical specifications
| Series | Proline X Performance Optimized Down Fire Wide |
|---|---|
| Compatible Driver | Arc Audio SW12 (dual 2 ohm or dual 4 ohm), quantity 1. Direct fit |
| Enclosure Type | Sealed, down fire, floor coupled |
| Intended Fitment | Long, low spaces where height or depth is the limit and 41 in of run is available |
| Firing Direction | Down firing. Feet ship uninstalled, so front or up firing is also possible |
| Chamber Configuration | Single chamber, windowed U-brace, one side-mounted terminal cup |
| External Width | 41 in |
| External Depth | 14 in |
| External Height | 5.125 in in the down fire position, excludes standoffs |
| Installed Height | 6.875 in including the 1.75 in standoffs |
| Dimension Reference | All external dimensions measured in down fire position |
| Standard 30 x 15 Version | 6 in tall, 0.74 cu ft net |
| Internal Volume, Gross | 0.801 cu ft |
| Internal Volume, Net | 0.752 cu ft after displacement and the brace |
| Height Set By | Airspace; 1.98 in clearance above the motor |
| Alignment, Coils in series | Qtc 1.001, Fc 53.1 Hz, F3 41.7 Hz anechoic |
| Alignment, Coils in parallel | Qtc 0.990, Fc 53.1 Hz, F3 41.9 Hz anechoic |
| Woofer Opening | 11 in |
| Mounting Depth Required | 2.4 in |
| Frame Outer Diameter | 12.5 in |
| Driver Displacement | 0.042 cu ft (Estimated; Arc Publishes None) |
| Arc Published Sealed Range | 0.65 Min / 0.8 Optimum / 1.0 Max (All Gross) |
| Driver Fs | 33.1 Hz Series / 33.0 Hz Parallel |
| Driver Qts | 0.624 Series / 0.616 Parallel |
| Driver Qes / Qms | 0.729 / 4.319 Series | 0.719 / 4.289 Parallel |
| Driver Vas | 33.44 Liters Series / 33.73 Liters Parallel |
| Driver Bl | 23.955 Tm Series / 12.024 Tm Parallel |
| Driver Mms | 278.61 g Series / 277.40 g Parallel |
| Driver Re | 7.23 Ohms Series / 1.81 Ohms Parallel |
| Driver Sd | 532.97 cm² |
| Driver Sensitivity | 85.22 dB (1W/1m) |
| Driver Power Handling | 400 Watts RMS / 800 Watts Peak |
| Driver Mounting | 8/32 Threaded Inserts | Stainless Steel Machine Screws Included |
| Voice Coil Configuration | Dual Voice Coil, Final Impedance Set At The Driver |
| Material | Langboard Elite 3/4 in MDF |
| Joinery | V-groove and dado, CNC cut on ShopSabre routers |
| Front Baffle | 1.5 in double baffle, outer layer machined as a flush recess |
| Internal Bracing | Windowed U-brace, dadoed to the shell |
| Corner Profile | Square (Down Fire series standard) |
| Terminal Cup | One Proline X ABS and carbon fiber composite, side mounted, pre-wired 12 gauge OFC |
| Standoffs | 1.75 in, included, shipped uninstalled |
| Damping | Polyfill installed as a light wall lining |
| Carpet | Plush black |
| Bundle Options | Enclosure only (bring your own Arc Audio SW12) |
| Warranty | 1 year limited (enclosure) |
| Built In | Tullahoma, Tennessee, USA |
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
0.752 cu ft against a 33.4 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 15.5 mm, and in this alignment a subsonic filter barely moves it.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 33.10 / 33.00 | Hz | free-air resonance |
| Qts | 0.624 / 0.616 | series / parallel | |
| Vas | 33.44 / 33.73 | L | equivalent compliance |
| Sd | 533.0 | cm² | effective piston area |
| Xmax | 15.5 | mm | one-way linear travel |
| Pe | 400 | W | continuous RMS |
| SPL | 84.1 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by arcaudio.com SW12 published specification. Curves computed against this enclosure’s actual net airspace.
From the shop floor
Installer's take
A 12 inch subwoofer that mounts in 2.4 inches, 2.23 front loaded. On 41 by 14 that puts a full 12 in a box 5.125 inches tall.
Height was solved to the airspace: 5.125 tall holds 0.752 net, against 0.74 in the standard box, and the motor clears the lid with 1.98 inches to spare. Same air, lower box.
Series lands at Qtc 1.001 with F3 41.7 Hz, parallel at Qtc 0.990 with F3 41.9 Hz. Pick your wiring on amplifier impedance, not sound.
Arc states sealed volume as gross; this box is 0.801 gross against their 0.8 optimum. 400 watts RMS, 800 peak, 532.97 square centimeters of cone.
Measure installed height, not cabinet height: 5.125 on its own, 6.875 with the 1.75 inch feet on. The standard 30 by 15 is still the pick if you do not have 41 inches of run.
Before you order
Questions
Why is this cabinet 41 inches wide instead of 30?
Because it trades length for depth and height. The standard Performance Optimized Down Fire platform is 30 wide by 15 deep; this one is 14 deep, 1 inch shallower, and 41 long. Spreading the airspace along 11 more inches lets the cabinet stand 5.125 inches tall instead of 6.
Fourteen inches of depth is the practical minimum, since a 12 inch frame needs about 13 inches of baffle. If your space is long and low rather than deep or tall, this is the shape that fits.
How does this compare to the standard 30 x 15 SW12 enclosure?
Same driver, different shape. The standard cabinet is 30 by 15 by 6 inches and holds 0.74 cubic feet net. This cabinet is 41 by 14 by 5.125 inches and holds 0.752 cubic feet net.
The airspace is effectively the same, so the driver behaves the same way in either. Choose the standard box when length is limited; choose this one when height or depth is the limit and you have 41 inches of run.
Does it matter whether I wire the voice coils in series or parallel?
Not for the enclosure alignment. In series the SW12 lands at Qtc 1.001, Fc 53.1 Hz and F3 41.7 Hz; in parallel at Qtc 0.990, Fc 53.1 Hz and F3 41.9 Hz.
Arc's two parameter sets are effectively identical, so choose your wiring based purely on the impedance your amplifier is stable and efficient into.
Why does Arc list gross volume when other brands list net?
Arc Audio publishes its sealed recommendations as gross volume, total internal volume before the driver's displacement, where most manufacturers state net. This cabinet is 0.801 cubic feet gross, on Arc's 0.8 optimum, and 0.752 cubic feet net.
Both figures appear in the specifications so you can compare against either convention.
Where is the terminal cup located on a down fire enclosure?
Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup, whether standard, wedge or down fire, which keeps the connection accessible with the baffle facing 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.
Why are the corners square instead of radiused?
Down Fire cabinets are built with square corners as a series standard. The 3 inch top down corner radius used on other Proline X alignments does not apply here. A down fire box is a low, long platform that sits flat against a floor or cargo deck, and square corners maximize usable internal volume for a given footprint while keeping the cabinet stable on its mounting surface.
How is this enclosure built?
V-groove and dado joinery, CNC cut on ShopSabre routers from Langboard Elite MDF. Every panel joint is a machined interlocking groove that locks the panels before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. The front baffle is a 1.5 inch double layer, the outer layer machined as a flush recess around the 11 inch cutout.
A windowed U-brace stiffens the long panels, and polyfill is installed as a light wall lining. Do not add more fill; packing a sealed box makes it act larger and moves the alignment off the 0.752 cubic feet it was built to. Assembled and inspected in Tullahoma, Tennessee.
Is the Arc Audio SW12 subwoofer included with this enclosure?
No. This listing is for the enclosure only. Bring your own Arc Audio SW12 in either dual 2 ohm or dual 4 ohm. The cutout and mounting depth are direct fit for either version.
Same series, same size
Alpine R2-W12
Alpine R2-W12
Alpine RSW12
Alpine RSW12
Alpine S2-W12
Arc Audio 10" Arc Series
Arc Audio ARC 12