
Performance Optimized · Datasheet
Performance Optimized Wedge Ported 8" Enclosure | Arc Audio ARC 8 Single 8" Ported enclosure
- Net volume
- 0.92 Cubic Feet
- Tuning
- 33.0 Hz
- Max mounting depth
- 4.750 Inches (Arc Audio Spec)
- Cutout
- 7.125 Inches (Arc Audio Spec)
- External dimensions
- 29.50 Inches W × 11.75 Inches H × 8.12 Inches / 12.40 Inches D
- Front baffle
- Vertical Baffle - Driver Fires Rearward Into The Trunk
- Alignment: 0.92 cu ft net vented at 33.0 Hz. F3 31.0 Hz anechoic, 0.91 dB passband ripple
- Driver: Arc Audio ARC 8 D2, 150 W RMS, 15.0 mm Xmax, 22.70 Hz Fs
- Build: Rear-firing wedge, 20 degree rear rake, V-groove and dado joinery, triangular side-exit slot port with a 1/2" rounded mouth, double 1.5" baffle, side-mounted terminal cup
- Cabinet: 29.50" W x 11.75" H x 12.40" D at base tapering to 8.12" D at top, 10.6 sq in port, ships dry
Technical specifications
| Series | Proline X Performance Optimized Wedge |
|---|---|
| Driver-Specific Fitment | Arc Audio ARC 8 D2 (Dual 2 Ohm) |
| Enclosure Type | Ported | Rear-Firing Trunk Wedge |
| Baffle Configuration | Vertical Baffle - Driver Fires Rearward Into The Trunk |
| Wedge Angle | 20 Degrees On The Rear (Seat-Side) Panel |
| External Width | 29.50 Inches |
| External Height | 11.75 Inches |
| Top Depth | 8.12 Inches |
| Base Depth | 12.40 Inches |
| Internal Volume (Gross) | 1.16 Cubic Feet |
| Internal Volume (Net After Displacement) | 0.92 Cubic Feet |
| Port Type | Triangular Slot | Bottom-Rear Corner | Straight, No Bend | Side Exit |
| Port Geometry | Isosceles, 4.75 Inch Legs, 10.6 Square Inches, 22.88 Inches Long, Side Mouth |
| Port Tuning (Fb) | 33.0 Hz |
| Port Mouth | Triangle Through Side A, 1/2 In Roundover On All Three Edges, 19.4 Square Inches At The Face |
| Port Throat | Open Far End, 4.87 In Gap To Side B, 3/8 In Roundover On The Panel End |
| Port Air Velocity | 16.6 m/s In The Channel, 9.1 m/s At The Flared Mouth (17.0 m/s Chuff Threshold) |
| Predicted F3 | 31.0 Hz (Anechoic) |
| Passband Ripple | 0.91 dB (Anechoic) |
| Subsonic Filter | 26 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure |
| Driver Fs | 22.70 Hz |
| Driver Qts | 0.289 |
| Driver Qes / Qms | 0.317 / 3.331 |
| Driver Vas | 48.140 Liters / 1.700 Cubic Feet |
| Driver Sd | 231.0 Square Centimeters |
| Driver Re | 3.8 Ohm |
| Driver Xmax | 15mm (One-Way at 70% BL) |
| Excursion Design Basis | Derated To 12.8mm For Alignment - Arc Audio Publishes At 70% BL |
| Driver Displacement | 0.04 Cubic Feet (Published by Arc Audio) |
| Driver Sensitivity | 85.4 dB |
| Driver Power Handling | 150 Watts RMS |
| Driver Overall Diameter | 8.312 Inches (Arc Audio Spec) |
| Mounting Depth Required | 4.750 Inches (Arc Audio Spec) |
| Cutout Diameter | 7.125 Inches (Arc Audio Spec) |
| Material | Langboard Elite 3/4" MDF |
| Construction | ShopSabre CNC / Two Windowed C Braces At The Third Points, Seated On The Port Panel |
| Joinery | V-Groove and Dado (CNC-Cut) |
| Front Baffle Construction | Double-Layer 1.5" MDF | Cosmetic Front Layer Routed For The Acrylic Insert |
| Mounting Hardware | Threaded Inserts At Every Mounting Location | Stainless Steel Machine Screws Included |
| Voice Coil Configuration | Dual 2 Ohm |
| Terminal Cup | Proline X ABS/Carbon Fiber Composite | Side Mounted, Opposite The Port | 12g OFC Pre-Wired |
| Damping | None - Ships Dry. Polyfill Detunes A Ported Enclosure |
| Recommended Power | 105-150 Watts RMS (Arc Audio Rated: 150W RMS) |
| Carpet Finish | Plush Black |
| Weight | 40 lb |
| Bundle Options | Enclosure Only (Bring Your Own Arc Audio ARC 8) |
| Warranty | 1-Year Limited (Enclosure) |
| Manufactured | Tullahoma, Tennessee, USA |
Performance in this enclosure
01Is this driver right for a ported box?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
0.92 cu ft net against a 48.1 L Vas, vented at 33.0 Hz.
03Perceived Ported vs Sealed
This cabinet, 0.92 cu ft net vented at 33.0 Hz, against Arc's recommended (optimum) sealed box, 0.45 cu ft (0.45 gross, 0.41 net after the driver).
04Real World Ported vs Sealed
The same two boxes with cabin gain applied, 45 Hz corner, 18 dB ceiling.
05The 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 Arc Audio's published 15.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.
Installer's take
An eight with a twelve's Vas. 22.7 Hz resonance, 0.29 Qts, 48 litres; any eight-inch cabinet is small for that much compliance, mine included, and the result is a very flat passband, 0.91 dB of ripple, with a 31.0 Hz F3 and 3.87 dB of in-car spread. The Down Fire version reads 4.66.
150 watts is the ceiling. Arc publish no Mms for the 8, so the Vas cannot be cross-checked the way the 10 and 12 were. Xmax is 15 mm with no stated basis, derated to 12.8; the cone uses 5.9 of that at rated power with the 26 Hz filter set. A 4.75 inch leg puts the base at 12.40, deeper than the 11.75 inch height.
Questions
Why is this enclosure tuned to 33.0 Hz?
A 0.29 Qts rolls off early and any eight-inch cabinet is small for this much compliance, ours included, so the passband is flat, 0.91 dB of anechoic ripple, with an F3 of 31.0 Hz and 3.87 dB of in-car spread across 25 to 60 Hz. The Down Fire version reads 4.66. The port uses 22.88 of the 25.61 inches available and runs at 16.6 metres per second in the channel against a 16.8 limit, 9.1 at the mouth. Tuning is chosen for in-car response rather than an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz. In this cabinet that lands at 3.9 dB of in-car spread across 25 to 60 Hz.
Why the 20 degree wedge, and why rear-firing?
The raked face is the seat side. A factory rear seat back leans about 20 degrees off vertical, so the cabinet sits flat against it and uses floor a square box wastes. The baffle stays vertical and fires rearward into the trunk, which acts as the acoustic extension into the cabin. This one is 12.40 inches deep at the base and 8.12 at the top, 29.50 wide and 12 tall.
Do I need a subsonic filter?
Yes, at 26 Hz, 24 dB per octave. Below tuning a vented box stops loading the cone and excursion runs away toward DC. With the filter in place this cabinet puts the Arc Audio ARC 8 at 47 percent of its usable travel at full rated power; without it there is no meaningful number to quote.
How much power can I run, and at what impedance?
Arc Audio rate the ARC 8 at 150 W RMS and that is the thermal ceiling. The Performance Graphs tab shows the mechanical limit, the power at which the cone reaches the end of its travel in this cabinet: here the cone sits at 47 percent of usable travel at the rating, so heat is what stops you, not travel. A D2 coil is 4 ohms in series or 1 ohm in parallel; run series unless the amplifier is rated for 1 ohm. A D4 is 8 series or 2 parallel.
Would a sealed box be better for me?
The two alignments converge at the bottom of the band on this driver rather than crossing cleanly, so there is no meaningful subsonic advantage either way. Above 25 Hz the vent is the louder of the two. The Performance Graphs tab plots this cabinet against Arc's recommended (optimum) sealed box, 0.45 cu ft (0.45 gross, 0.41 net after the driver).
How does the side port work?
It is a triangular slot in the bottom-rear corner: the floor and the raked back wall are two sides, one bevelled panel is the third. It runs across the cabinet, opens into the box through a 4.87 inch gap at the far end and exits through the side panel as the same triangle. Straight, no bend: 22.88 inches of path and 10.6 square inches of channel running at 16.6 metres per second, 54 percent of its turbulence limit. The three mouth edges are rounded over at 1/2 inch, so the opening at the face is 19.4 square inches and the air leaves it at 9.1 metres per second against the 17.0 threshold where a slot port starts to chuff; the panel's throat end is rounded at 3/8 inch for the same reason. The terminal cup is on the other side.
Does this enclosure ship with polyfill?
No, and do not add any. Every sealed Proline X enclosure ships with polyfill; a ported one must not, because damping changes the effective volume the port is tuned against. The port here is cut to 22.88 inches for 33.0 Hz. Stuff it and you move the tuning without shortening the port.
Is the ARC 8 included?
No. This is an enclosure only, cut for the Arc Audio ARC 8 specifically: the 7.125 inch cutout, the 4.750 inch mounting depth allowance and the 0.92 cubic foot alignment all come from Arc Audio's published parameters. It fits both coil versions; the alignment published here is the D2. Bring your own driver.
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