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Performance Optimized · Datasheet

Performance Optimized Wedge Wide Sealed Triple 12" Enclosure Rockford Fosgate T0D412 · Triple 12" Sealed enclosure

Net volume
1.144 cu ft per driver, 3.43 cu ft total, after both dividers and Rockford Fosgate's published 0.106 cu ft displacement per driver
Max mounting depth
6.88 in required; 3.18 in clearance above the motor against the raked rear panel
External dimensions
44 in W × 17 in at the seat face H × 16.55 in at the base D
Front baffle
1.5 in double baffle, outer layer machined as a flush recess
Buy at Audio IntensityFactory-direct, ships from Tullahoma
Rockford Fosgate T0D412Buy at Audio Intensity
  • Best For: Triple Rockford Fosgate T0D412 SUV Cargo-Floor Builds
  • Net Volume: 1.144 cu ft per Driver (3.43 cu ft Net Total)
  • Driver Match: Three Rockford Fosgate T0D412 (Dual 4 Ohm), matched
  • Construction: 3 Chambers | 44" Wide Wedge | V-Groove/Dado | Double 1.5" Baffle | 3 Terminal Cups

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge Wide
Compatible DriverRockford Fosgate T0D412, quantity 3, matched. Direct fit
ConfigurationTriple 12 inch sealed wedge, 3 chambers, 1 driver per chamber
Mounting PositionSUV cargo floor, raked face against the rear seat back
Firing DirectionRearward toward the liftgate. Not a down fire design
External Width44 in
External Height17 in at the seat face
External Depth16.55 in at the base, tapering to 10.36 in at the top
Internal Volume, Gross3.89 cu ft total
Internal Volume, Net Acoustic1.144 cu ft per driver, 3.43 cu ft total, after both dividers and Rockford Fosgate's published 0.106 cu ft displacement per driver
Driver Mounting Depth6.88 in required; 3.18 in clearance above the motor against the raked rear panel
Alignment Per DriverT0D412 Qtc 0.871, fc 42.7 Hz, F3 36.1 Hz anechoic
Woofer Openings3 at 11.250 in
Woofer LayoutOne row across the face
Frame Outer Diameter12.84 in
Fs / Qts / Qes / Qms26.0 Hz / 0.530 / 0.580 / 6.000
Vas / Sd / Xmax55.1 L / 548 cm2 / 15 mm
Driver Power Handling700 W RMS per driver, 2100 W RMS for the set of 3 (thermal rating)
Recommended Amplifier430-610 W RMS per driver, 1,290-1,830 W RMS for the full set, at 2.67 ohms
Parameter SourceRockford Fosgate published specifications
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Internal BracingTwo full-height 3/4 in dividers
Driver MountingThreaded inserts, stainless machine screws included
Terminal CupsThree Proline X ABS and carbon fiber composite, on the rear panel, one per chamber, pre wired 12 gauge OFC
Acrylic InsertGloss black acrylic baffle insert standard
DampingLight polyfill wall lining in every chamber, does not alter acoustic volume
CarpetPlush black
Shipping Weight79 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.144
cu ft per driver
System Qtc
0.87
sealed
Half power
36.1
Hz · F3
Xmax at
521
W RMS per driver · no filter
With 25 Hz subsonic
620
W RMS per driver · +19%
Amplifier, per driver
430–610
W RMS recommended
This enclosure holds 1.144 cu ft net per driver. In it the Rockford Fosgate T0D412 runs a system Qtc of 0.87 with half power at 36.1 Hz, and the cone reaches its 14.8 mm travel limit at 521 W per driver, below the driver’s 700 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 620 W per driver — +99 W, or 19 percent more power for the same 14.8 mm of travel.

00Sizing the amplifier

Every wattage on this panel is per driver. This cabinet holds three, so the amplifier feeds all three at once.

Per driver 430–610 W RMS  ×  3 drivers  =  full set 1,290–1,830 W RMS at 2.67 ohms
Look for a mono amplifier rated 1,290–1,830 W RMS at 2.67 ohms, the load the set wires to most easily. Travel sets the top here, not heat: past 620 W per driver the cone runs beyond Xmax even with the subsonic set, under the driver’s 700 W thermal rating. The top of the range needs the 25 Hz subsonic filter set; without it, keep each driver under 521 W, where the cone reaches Xmax unfiltered. Below the bottom of the range it will play, just with less headroom; above the top you are buying power the drivers cannot use.

01Is it a sealed driver?

Efficiency bandwidth product places the motor before anything else is decided.

EBP = Fs ÷ Qes = 44.8
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 Dual 4 Ohm 44.8
Dual 4 Ohm · EBP 44.8
EBP under 50 means a motor that wants a sealed load. The T0D412 sits at 44.8, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

1.144 cu ft against a 55.1 L Vas.

α = Vas ÷ Vb = 1.70  ·  Fc = Fs√(α+1) = 43 Hz  ·  Qtc = 0.87
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
Dual 4 Ohm · Qtc 0.87, Fc 43 Hz, F3 36.1 Hz
The box lifts resonance from 26.0 Hz free-air to 43 Hz and half power lands at 36.1 Hz, anechoic, before any cabin gain. Figures are Rockford Fosgate’s published parameters; Qes and Qms reproduce the printed Qts. This cabinet holds three drivers in three separate sealed chambers of 1.144 cubic feet each, the volume plotted here.

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 14.8 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 521 W per driver unfiltered  →  620 W per driver with a 25 Hz subsonic
20 30 50 70 100 150 200 0 4 8 12 16 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 14.8 mm 521 W reaches Xmax here
Dual 4 Ohm · 521 W, no filterDual 4 Ohm · 620 W with subsonic at 25 Hz, 24 dB/octXmax 14.8 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 14.8 mm. Unfiltered that is 521 W per driver, reached first at 25 Hz. It sits under the 700 W the driver can take thermally, so the enclosure sets the ceiling, not the voice coil. The dashed traces are the same driver behind a subsonic filter at 25 Hz, 24 dB/oct: stopping the cone wasting travel below the passband lets it take 620 W per driver before hitting the same 14.8 mm. That is 19 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs26.00Hzfree-air resonance
Qts0.530Dual 4 Ohm
Vas55.10Lequivalent compliance
Sd548.0cm²effective piston area
Xmax14.8mmone-way linear travel
Pe700Wcontinuous RMS
SPL84.1dB1 W / 1 m, derived from T/S

Driver parameters as published by Rockford Fosgate T0D412 published specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Start with the size. 1.144 cubic feet per driver puts the T0D412 at Qtc 0.871, resonance 42.7 Hz, half power 36.1 Hz anechoic. That is Rockford Fosgate's number, not ours: the cabinet is built to the maker's recommended sealed size. Butterworth on these figures wants 2.50, which on this platform means deeper than the 23 in platform allows. It is a small lift near resonance, 0.5 dB above flat.

Measure the base depth, not the top. This cabinet is 16.55 in deep where it meets the floor, 10.36 at the top, 44 wide and 17 tall. In an SUV the 44 has to clear between the rear wheel wells at floor height, the base depth is measured from the seat back with the seat upright and latched, and the 17 has to clear the cargo cover.

All three terminal cups are on the rear panel, and the rear panel is the face that goes against the seat back. Wire all three before the box goes in, with enough slack to slide it into place; once the raked face is against the seat you cannot reach them.

Each driver has its own chamber. The outer two are set 0.62 in toward the ends of their chambers so the 12.84 in frames clear each other; that is deliberate, not an off-center cut.

Impedance. T0D412: wire for 2.67 ohms (coils in series, the three cups in parallel), the load most monoblocks are built to deliver full power into; 6 ohms is the other clean option (coils in parallel, the three in series). Work the load out before you buy the amplifier, not after.

Power. Size the amplifier for the set, not one driver: 430 to 610 W RMS per driver is 1,290 to 1,830 W RMS across all 3 at 2.67 ohms. On this driver travel sets the top, not heat: Xmax arrives at 620 W per driver with a 25 Hz subsonic, under the 700 W rating. Set the 25 Hz subsonic to use the top of that range; without it keep each driver under 521 W. At 1,830 W the charging system is part of the install: alternator output, the big three, and a battery that holds voltage under load.

Rockford Fosgate's Qes and Qms reproduce the printed Qts within 3 percent, so the alignment rests on a self-consistent set.

Polyfill is in as a wall lining in every chamber. Do not add more: it makes the box act larger and walks Qtc off 0.87.

Before you order

Questions

Does this fit the Rockford Fosgate T0D412, and its coil versions?

Yes. Each opening is cut to 11.250 in for the 12.84 in frame, and the 6.88 in deep motor clears the raked rear panel with 3.18 in to spare. Coil versions of the Rockford Fosgate T0D412 share the frame, cutout and mounting depth, so any of them drops in. The alignment on this page is computed on the T0D412 parameters.

Run three matched drivers, same model and same coil, so every chamber sees the alignment on this page.

Why 1.144 cubic feet per driver, and what alignment does it target?

On Rockford Fosgate's published Fs 26.0 Hz, Qts 0.530 and Vas 55.1 liters, 1.144 cubic feet per driver gives Qtc 0.871, system resonance 42.7 Hz and half power 36.1 Hz.

The cabinet is sized to the maker's recommended sealed size, 1.14 cubic feet per driver, to keep it realistic for a cargo floor. Maximally flat would need 2.50 cubic feet per driver; this size trades a little low end for a compact box and a small lift near resonance, 0.5 dB above flat.

What amplifier power should I run, and how should I wire it?

Rockford Fosgate rates the T0D412 at 700 watts RMS per driver. Recommended amplifier: 430 to 610 W RMS per driver, 1,290 to 1,830 W RMS for the full set of 3. Travel, not heat, sets the top: the cone reaches Xmax at 620 W per driver with a 25 Hz subsonic set, under the 700 W rating. The top of that range needs the 25 Hz subsonic; without it keep each driver under 521 W.

Each T0D412 has two 4 ohm voice coils, 8 ohms in series or 2 ohms in parallel. With each driver's coils in series and the three cups in parallel, the three present 2.67 ohms to a mono amplifier. With each driver's coils in parallel and the three in series, they present 6 ohms. Three drivers do not reach the round loads a pair does, so check the result against your amplifier's minimum stable impedance before powering up.

Will it fit my SUV?

It is 44 inches wide, 17 tall and 16.55 deep at the base, tapering to 10.36 at the top. Measure between the rear wheel wells, the floor depth with the seat upright, and the height under your cargo cover.

The raked face goes against the seat back and the woofers fire toward the liftgate.

Why are all three terminal cups on the back?

Each driver has its own sealed chamber, and the center chamber has no side wall to take a cup. Putting all three on the rear panel gives a matching set, one cup per chamber.

Wire them at the amplifier end; there is no cross-chamber wiring inside the cabinet.

What is the expected low-frequency extension?

Anechoic F3 is 36.1 Hz per driver with system resonance at 42.7 Hz.

Those figures exclude cabin gain. An SUV cabin adds real output below about 50 Hz, so in-vehicle response runs deeper than the numbers above.

Do I need to add polyfill or damping?

No. Polyfill is already installed as a light wall lining in every 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 moves the alignment away from 1.144 cubic feet per driver.

Are the drivers included?

No. This is an enclosure only. You receive the cabinet finished in plush black carpet with the gloss black acrylic baffle insert, three pre-wired terminal cups on the rear panel, the polyfill lining in place, threaded inserts and stainless machine screws.

Bring three matched Rockford Fosgate T0D412 drivers. The cabinet is cut direct fit to them, not a general purpose 12 inch box.

Same series, same size

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