
Performance Optimized · Datasheet
Performance Optimized Wedge Ported 12" Enclosure | Stereo Integrity SQL-12 Single 12" Ported enclosure
- Net volume
- 1.54 Cubic Feet
- Tuning
- 37.5 Hz
- Max mounting depth
- 7.000 Inches (Stereo Integrity Spec)
- Cutout
- 11.330 Inches (Stereo Integrity Spec)
- External dimensions
- 28.50 Inches W × 15.50 Inches H × 10.25 Inches / 15.89 Inches D
- Front baffle
- Vertical Baffle - Driver Fires Rearward Into The Trunk
- Alignment: 1.54 cu ft net vented at 37.5 Hz. F3 30.9 Hz anechoic, 4.13 dB passband ripple
- Driver: Stereo Integrity SQL-12, 1000 W RMS, 26.0 mm Xmax, 34.10 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: 28.50" W x 15.50" H x 15.89" D at base tapering to 10.25" D at top, 24.7 sq in port, ships dry
Technical specifications
| Series | Proline X Performance Optimized Wedge |
|---|---|
| Driver-Specific Fitment | Stereo Integrity SQL-12 (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 | 28.50 Inches |
| External Height | 15.50 Inches |
| Top Depth | 10.25 Inches |
| Base Depth | 15.89 Inches |
| Internal Volume (Gross) | 2.12 Cubic Feet |
| Internal Volume (Net After Displacement) | 1.54 Cubic Feet |
| Port Type | Triangular Slot | Bottom-Rear Corner | Straight, No Bend | Side Exit |
| Port Geometry | Isosceles, 7.25 Inch Legs, 24.7 Square Inches, 23.39 Inches Long, Side Mouth |
| Port Tuning (Fb) | 37.5 Hz |
| Port Mouth | Triangle Through Side A, 1/2 In Roundover On All Three Edges, 37.4 Square Inches At The Face |
| Port Throat | Open Far End, 3.36 In Gap To Side B, 3/8 In Roundover On The Panel End |
| Port Air Velocity | 27.0 m/s In The Channel, 17.8 m/s At The Flared Mouth (17.0 m/s Chuff Threshold) |
| Predicted F3 | 30.9 Hz (Anechoic) |
| Passband Ripple | 4.13 dB (Anechoic) |
| Subsonic Filter | 30 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure |
| Driver Fs | 34.10 Hz |
| Driver Qts | 0.570 |
| Driver Qes / Qms | 0.620 / 6.990 |
| Driver Vas | 22.500 Liters / 0.795 Cubic Feet |
| Driver Sd | 532.3 Square Centimeters |
| Driver Mms | 387.90 g |
| Driver BL | 21.00 |
| Driver Re | 3.3 Ohm |
| Driver Xmax | 26mm (One-Way at 70% BL) |
| Excursion Design Basis | Derated To 22.1mm For Alignment - Stereo Integrity Publishes At 70% BL |
| Driver Displacement | 0.15 Cubic Feet (Published by Stereo Integrity) |
| Driver Sensitivity | 83.1 dB |
| Driver Power Handling | 1000 Watts RMS |
| Driver Overall Diameter | 12.910 Inches (Stereo Integrity Spec) |
| Mounting Depth Required | 7.000 Inches (Stereo Integrity Spec) |
| Cutout Diameter | 11.330 Inches (Stereo Integrity 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 | 700-1000 Watts RMS (Stereo Integrity Rated: 1000W RMS) |
| Carpet Finish | Plush Black |
| Weight | 50 lb |
| Bundle Options | Enclosure Only (Bring Your Own Stereo Integrity SQL-12) |
| 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
1.54 cu ft net against a 22.5 L Vas, vented at 37.5 Hz.
03Perceived Ported vs Sealed
This cabinet, 1.54 cu ft net vented at 37.5 Hz, against the 1.00 cu ft sealed wedge we build for this driver (PO 12-S W SQL12).
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 Stereo Integrity's published 26.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.
Installer's take
Stereo Integrity's own vented box for the SQL-12 is 1.7 cubic feet at 27 Hz through a 22 inch port. A wedge holds a straight triangular port no longer than about 23.5 inches at this width, so it cannot tune that low; this cabinet is the nearest thing the wedge can do, 1.54 cubic feet at 37.5 Hz with a 30.9 Hz F3 on 4.13 dB of ripple. It reads 6.52 dB in the car, which is more spread than the rest of the line carries, and I am telling you that up front.
The port is the other thing to know. At the full 1000 watts it runs 27.0 metres per second in the channel and 17.8 at the mouth, both past the limits I hold the rest of the line to, and I chose to build it anyway because at the 300 to 500 watts most installs actually deliver those figures fall well inside. If you run a clean kilowatt into it on sustained low notes, you will hear the port. Xmax is quoted at 70 percent BL, derated from 26 to 22.1 mm, and the cone uses 7.8 of that at rated power with the subsonic filter set. The sealed SQL-12 wedge we build is the calmer alternative.
Questions
Why is this enclosure tuned to 37.5 Hz?
Stereo Integrity's own vented box is 1.7 cubic feet at 27 Hz with a 22 inch port, and a straight triangular port in a wedge cannot reach that length, so this cabinet tunes higher: F3 30.9 Hz anechoic on 4.13 dB of ripple and 6.52 dB of in-car spread across 25 to 60 Hz. The port takes 23.39 of the 23.48 inches the width allows and runs at 27.0 metres per second in the channel at the full 1000 watts, over the 24.7 limit this line normally holds, with 17.8 at the rounded mouth against a 17 target. Both figures were reviewed and accepted for this cabinet; at the power most installs run, they fall well inside. 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 6.5 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 15.89 inches deep at the base and 10.25 at the top, 28.50 wide and 16 tall.
Do I need a subsonic filter?
Yes, at 30 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 Stereo Integrity SQL-12 at 35 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?
Stereo Integrity rate the SQL-12 at 1000 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 35 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?
Below about 25 Hz, yes. The sealed wedge we build for it is louder down there by up to 4.9 dB, because a sealed box rolls off gently where a vented one falls away steeply under tuning. Above that this alignment is the louder of the two for the same power. The Performance Graphs tab plots this cabinet against the 1.00 cu ft sealed wedge we build for this driver (PO 12-S W SQL12).
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 3.36 inch gap at the far end and exits through the side panel as the same triangle. Straight, no bend: 23.39 inches of path and 24.7 square inches of channel running at 27.0 metres per second, 60 percent of its turbulence limit. The three mouth edges are rounded over at 1/2 inch, so the opening at the face is 37.4 square inches and the air leaves it at 17.8 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 23.39 inches for 37.5 Hz. Stuff it and you move the tuning without shortening the port.
Is the SQL-12 included?
No. This is an enclosure only, cut for the Stereo Integrity SQL-12 specifically: the 11.330 inch cutout, the 7.000 inch mounting depth allowance and the 1.54 cubic foot alignment all come from Stereo Integrity's published parameters. It fits both coil versions; the alignment published here is the . Bring your own driver.
Other Performance Optimized models
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- Alpine S2-W12 Dual 12" Sealed
- Arc Audio 10" Arc Series Dual 12" Sealed
- Arc Audio 12" Arc Series Dual 12" Sealed
- Audiofrog GB12 Dual 12" Sealed
- Dual Kicker Solo X 12" Subwoofers Dual 12" Sealed
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