
Performance Optimized · Datasheet
Performance Optimized Down Fire Ported 10" Enclosure | Rockford Fosgate R2SD4-10 Single 10" Ported enclosure
- Net volume
- 1.26 Cubic Feet
- Tuning
- 35.5 Hz
- Max mounting depth
- 3.417 Inches (Rockford Fosgate Spec)
- Cutout
- 9.125 Inches (Rockford Fosgate Spec)
- External dimensions
- 31 Inches W × 7.75 Inches H × 15.00 Inches D
- Front baffle
- Down Firing - Driver Fires Toward Floor
- Alignment: 1.26 cu ft net vented at 35.5 Hz. F3 31.7 Hz anechoic, 2.49 dB passband ripple
- Driver: Rockford Fosgate R2SD4-10 D4, 200 W RMS, 8.0 mm Xmax, 39.30 Hz Fs
- Build: Proline X V-groove and dado joinery, L-wrap slot port with a faceted 90 degree bend, double-layer 1.5" baffle, side-mounted terminal cup
- Cabinet: 31" W x 15.00" D x 7.75" H measured in down fire position, 9.50" tall installed on its feet, square corners, ships dry
Technical specifications
| Series | Proline X Performance Optimized Down Fire |
|---|---|
| Driver-Specific Fitment | Rockford Fosgate R2SD4-10 D4 (Dual 4 Ohm) |
| Enclosure Type | Ported | Down Fire Geometry | Floor-Coupled |
| Baffle Configuration | Down Firing - Driver Fires Toward Floor |
| External Width | 31 Inches |
| External Depth | 15.00 Inches |
| External Height | 7.75 Inches (Cabinet Only) |
| Feet | Included - 1.75 Inch Standoff, Required For Down Fire Operation |
| Installed Height | 9.50 Inches (7.75 Cabinet Plus 1.75 Feet) - MEASURE AGAINST THIS, NOT THE CABINET HEIGHT |
| Dimension Reference | All External Dimensions Measured In Down Fire Position |
| Internal Volume (Gross) | 1.39 Cubic Feet |
| Internal Volume (Net After Displacement) | 1.26 Cubic Feet |
| Port Type | L-Wrap Slot | One Folded Wall | Single Faceted 90 Degree Bend |
| Port Tuning (Fb) | 35.5 Hz |
| Port Channel | 3.25 x 6.25 Inches (20.3 Square Inches) |
| Port Path Length | 27.05 Inches (Centreline) |
| Port Mouth Area | 17.7 Square Inches (2.00 Inch Corner Chamfer) |
| Port Air Velocity | 13.6 m/s At Tuning (17.0 m/s Chuff Threshold) |
| Predicted F3 | 31.7 Hz (Anechoic) |
| Passband Ripple | 2.49 dB (Anechoic) |
| Subsonic Filter | 28 Hz High-Pass, 24 dB/Octave - REQUIRED On A Vented Enclosure |
| Driver Fs | 39.30 Hz |
| Driver Qts | 0.730 |
| Driver Qes / Qms | 0.810 / 7.000 |
| Driver Vas | 21.700 Liters / 0.766 Cubic Feet |
| Driver Sd | 333.0 Square Centimeters |
| Driver Re | 6.6 Ohm |
| Driver Xmax | 8mm (One-Way) |
| Driver Displacement | 0.04 Cubic Feet (Published by Rockford Fosgate) |
| Driver Sensitivity | 82.5 dB |
| Driver Power Handling | 200 Watts RMS |
| Driver Overall Diameter | 10.840 Inches (Rockford Fosgate Spec) |
| Mounting Depth Required | 3.417 Inches (Rockford Fosgate Spec) |
| Cutout Diameter | 9.125 Inches (Rockford Fosgate Spec) |
| Woofer Ring | 11.750 Inch OD, Bonded Under The Baffle In A Machined Recess |
| Material | Langboard Elite 3/4" MDF |
| Construction | ShopSabre CNC / Windowed Brace Between Cutout And Port Terminus |
| Joinery | V-Groove and Dado (CNC-Cut) |
| Front Baffle Construction | Double-Layer 1.5" MDF | Outer Layer Flush Recess, Driver Mounts To Inner Layer |
| Corner Profile | Square (Down Fire Series Standard) |
| Mounting Hardware | 8 x #8-32 Hurricane Nuts Fitted (16 Positions Cut For Driver Orientation) | Stainless Steel Machine Screws Included |
| Voice Coil Configuration | Dual 4 Ohm |
| Terminal Cup | Proline X ABS/Carbon Fiber Composite | Side Mounted | 12g OFC Pre-Wired |
| Damping | None - Ships Dry. Polyfill Detunes A Ported Enclosure |
| Recommended Power | 140-200 Watts RMS (Rockford Fosgate Rated: 200W RMS) |
| Carpet Finish | Plush Black |
| Bundle Options | Enclosure Only (Bring Your Own Rockford Fosgate R2SD4-10) |
| 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
1.26 cu ft net against a 21.7 L Vas, vented at 35.5 Hz.
03Perceived Ported vs Sealed
This cabinet, 1.26 cu ft net vented at 35.5 Hz, against Rockford Fosgate's recommended sealed box, 0.70 cu ft.
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 Rockford Fosgate's published 8.0 mm. The two traces are the same cabinet with the subsonic filter switched on and switched off.
Installer's take
The shallowest Rockford ten I build for is also the flattest in the car. 2.3 dB against the P2's 2.36, the P1's 2.49, and a long way clear of the P3 at 4.76 and the T1 at 4.78.
That is the damping doing it. A 0.73 Qts with 21.7 litres of compliance is a motor that does not want to ring, and a vented box built around a driver like that sits flat without being forced. The port ends up at 31 percent of its turbulence limit and 13.6 metres per second at the mouth.
The trade is power. 200 watts, 8.0 mm of travel. That is where the depth came from. If your install has room for 6.38 inches, the T1 ten is 600 watts and 16 mm and it is a genuinely different product, but its in-car curve is 4.78 dB and you should look at both numbers before deciding which one you actually want.
Dual 4 ohm: 2 ohms parallel or 8 ohms series. Subsonic at 28 Hz. Ships dry.
Questions
Why is this enclosure tuned to 35.5 Hz?
A 39.3 Hz resonance with 21.7 litres of Vas and a 0.73 Qts is a compliant, heavily damped motor, and heavy damping is what keeps a vented alignment from peaking. 1.26 cubic feet at 35.5 Hz produces an F3 of 31.7 Hz with the port at 31 percent of its turbulence limit. Tuning is chosen for in-car response rather than for an anechoic curve: a vehicle adds roughly 12 dB per octave below about 45 Hz, so a box tuned very low reinforces a region the cabin is already reinforcing and leaves 40 to 60 Hz thin. In this cabinet that lands at 2.3 dB of in-car spread across 25 to 60 Hz, which is where kick and bass fundamentals live.
Does this enclosure ship with polyfill?
No, and on this build in particular do not add any. Every sealed Proline X enclosure ships with polyfill pre-installed; a ported one must not, because damping material changes the effective volume the port is tuned against. The port on this cabinet is cut to 27.05 inches of centreline path for 35.5 Hz. Stuff it and you move the tuning without shortening the port, which gives you a mistuned box rather than a bigger-sounding one. The 2.49 dB passband you are paying for depends on it staying dry.
Do I need a subsonic filter?
Yes, at 28 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 Rockford Fosgate R2SD4-10 at 83 percent of its usable travel at full rated power; without it there is no meaningful number to quote, because the excursion curve does not converge. On a sealed build a subsonic filter is an improvement. Here it is required equipment.
How much power can I run?
Rockford Fosgate rate the R2SD4-10 at 200 W RMS and that is the thermal ceiling. The figures on the Performance Graphs tab are a different quantity: they are mechanical limits, the power at which the cone reaches the end of its linear travel in this specific cabinet. Here the cone sits at 83 percent of usable travel at the driver's own rating, so heat is what stops you, not travel. Final wired impedance and amplifier output are separate questions again.
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 for the same power. The Performance Graphs tab plots this cabinet, 1.26 cubic feet vented at 35.5 Hz, against Rockford Fosgate's recommended sealed box, 0.70 cu ft, so you can judge it yourself.
What is the L-wrap port and why does it matter?
It is a slot port formed by one folded wall: a leg down the long side of the cabinet past the woofer ring, one faceted 90 degree bend, and a leg across the end opening through a chamfered corner. On this cabinet that is 27.05 inches of centreline path and 20.3 square inches of channel, exiting a 17.7 square inch mouth. Air leaves at 13.6 metres per second at tuning against a 17.0 threshold, and the channel runs at 31 percent of its turbulence limit. One wall and one bend rather than a serpentine's three means less wall area inside the box, fewer joints to leak, and one place for flow to separate instead of three.
How is this enclosure built?
V-groove and dado joinery in 0.75 inch Langboard Elite MDF with a double-layer 1.5 inch baffle. The driver mounts to a 11.750 inch ring bonded under the baffle in a machined recess, carrying eight #8-32 hurricane nuts so it threads into steel rather than MDF. A windowed brace sits 3.42 inches clear of the cutout edge and 2.11 inches clear of the port terminus; the window is not weight saving, a solid panel there would split the cavity and make the box a bandpass. Walls seat into dados in both the lid and the baffle. Square corners, plush black carpet, side-mounted terminal cup.
Is the R2SD4-10 included?
No. This is an enclosure only, cut and folded for the Rockford Fosgate R2SD4-10 specifically. The 9.125 inch cutout, the 3.417 inch mounting depth allowance and the 1.26 cubic foot alignment all come from Rockford Fosgate's published parameters for this exact driver, and the port is sized against its Xmax and power rating. It is not a universal box with a 10 inch hole in it. Bring your own driver.
Other Performance Optimized models
- Alpine R2-W10 Dual 10" Sealed
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- Alpine S2-W10 Dual 10" Sealed
- Arc Audio SW10 Dual 10" Sealed
- Audiofrog GB10 Dual 10" Sealed
- Audiofrog GB10 Dual 10" Sealed
- Audiomobile GT2 Dual 10" Sealed
- Diamond Audio DMD-SH Dual 10" Sealed