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Performance Optimized · Datasheet

Performance Optimized Down Fire Sealed Dual 12" Enclosure Ampere Audio AA-3.0 12 · Dual 12" Sealed enclosure

Net volume
0.83 cu ft per chamber after the divider and the driver displacement
Max mounting depth
10.25 in required, 0.75 in clearance above the motor
External dimensions
30.00 in W × 11.75 in in the down fire position H × 15.00 in D
Front baffle
1.5 in double baffle, outer layer machined as a flush recess
Buy at Audio IntensityFactory-direct, ships from Tullahoma
Ampere Audio AA-3.0 12Buy at Audio Intensity
  • Alignment: 0.83 cu ft net per chamber, Qtc 0.61, F3 52.0 Hz; height set by the motor, not the airspace
  • Drivers: Pair of Ampere Audio AA-3.0 12 (dual 2 ohm), 2000 W RMS each, 29 mm Xmax, 10.25 in mounting depth
  • Chambers: Two fully separate sealed chambers, 3/4" MDF full divider, one shared side-mounted terminal cup
  • Standoffs: Included, 1.75 in, shipped uninstalled. Installed height near 13.50 in
  • Cabinet: 30.00"W x 15.00"D x 11.75"H in down fire position, excludes standoffs, square corners

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Down Fire
Compatible DriverAmpere Audio AA-3.0 12 (dual 2 ohm), quantity 2. Direct fit
ConfigurationDual 12 inch, two separate chambers, sealed down fire
Mounting PositionTrunk or cargo floor, baffle facing down on standoffs
Firing DirectionDownward. Feet ship uninstalled, so front or up firing is also possible
External Width30.00 in
External Depth15.00 in
External Height11.75 in in the down fire position, excludes standoffs
Installed Height13.50 in including the 1.75 in standoff
Internal Volume, Gross2.04 cu ft total
Internal Volume, Net Acoustic0.83 cu ft per chamber after the divider and the driver displacement
Height Set ByDriver clearance: the 10.25 in motor, not the airspace
Driver Mounting Depth10.25 in required, 0.75 in clearance above the motor
Floor Slot0.87 times the cone area at the 1.75 in standoff
Alignment, dual 2 ohm per chamberQtc 0.607, fc 43.6 Hz, F3 52.0 Hz anechoic
Woofer Opening11.12 in, two, Ampere's published cutout
Frame Outer Diameter12.50 in
Bolt CircleNot printed by Ampere; threaded insert kit included
Driver Displacement0.165 cu ft, estimated; Ampere publishes none
dual 2 ohm Fs / Qts / Qes / Qms / Vas33.8 Hz / 0.47 / 0.53 / 4.16 / 15.6 L
Driver Sd452 cm2, derived from Ampere's Vas, Fs and moving mass
Xmax29 mm one way, Ampere spec
Driver Power Handling2000 W RMS per driver
Wiring OptionsThis cabinet is for the AA-3.0 12 dual 2 ohm; a matched pair should share a coil. A pair of dual 2 ohm drivers lands on 2 ohms with each woofer's coils in series and the two woofers in parallel, or 8 ohms all in series. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for, so series wiring is the safe default.
Parameter SourceAmpere Audio published T/S and dimension tables, AA-3.0 series page
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery, square corners
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Internal BracingFull-height 3/4 in divider
Driver MountingThreaded insert kit included, NOT pre-installed: Ampere prints no bolt circle
Terminal CupsOne Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC to both driver positions
StandoffsIncluded, 1.75 in, shipped uninstalled
DampingLight polyfill wall lining in both chambers, does not alter acoustic volume
CarpetPlush black
Shipping Weight44 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
0.83
cu ft per chamber
System Qtc
0.61
sealed
Half power
52.0
Hz · F3
Xmax at
2933
W RMS · no filter
With 25 Hz subsonic
4676
W RMS · +59%
Amplifier
2000
W RMS recommended
This enclosure holds 0.83 cu ft net per chamber. In it the Ampere Audio AA-3.0 12 runs a system Qtc of 0.61 with half power at 52.0 Hz, and the cone reaches its 29.0 mm travel limit at 2933 W, above the driver’s 2000 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 4676 W — +1743 W, or 59 percent more power for the same 29.0 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 63.8
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 D2 63.8
D2 · EBP 63.8
At 63.8 the AA-3.0 12 sits in the transition band, not the sealed band. That is not a mismatch: a transition motor works in either alignment, and sealed buys a smaller box and a gentler roll-off at the cost of some low-end output. Stage 02 shows what this airspace actually does with it.

02What the box does to it

0.83 cu ft against a 15.6 L Vas.

α = Vas ÷ Vb = 0.67  ·  Fc = Fs√(α+1) = 44 Hz  ·  Qtc = 0.61
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
D2 · Qtc 0.61, Fc 44 Hz, F3 52.0 Hz
The box lifts resonance from 33.8 Hz free-air to 44 Hz and half power lands at 52.0 Hz, anechoic, before any cabin gain. Ampere prints no cone area for this driver; it is derived from Ampere’s own Vas, Fs and moving mass. Driver displacement is not published and is estimated. Only the D2 coil is plotted: the other version falls outside a well-behaved sealed alignment in this cabinet.

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

PXmax = 2933 W unfiltered  →  4676 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 8 16 24 32 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 29.0 mm 2933 W reaches Xmax here
D2 · 2933 W, no filterD2 · 4676 W with subsonic at 25 Hz, 24 dB/octXmax 29.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 29.0 mm. Unfiltered that is 2933 W, reached first at 20 Hz. It sits above the 2000 W the driver can take thermally, so the voice coil gives up before the suspension does. 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 4676 W before hitting the same 29.0 mm. That is 59 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs33.80Hzfree-air resonance
Qts0.470D2
Vas15.60Lequivalent compliance
Sd451.7cm²effective piston area
Xmax29mmone-way, as Ampere publish it
Pe2000Wcontinuous RMS
SPL82.4dB1 W / 1 m, derived from T/S

Driver parameters as published by Ampere Audio published T/S table. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

0.83 cubic feet per chamber: Qtc 0.607 on the dual 2 ohm, F3 52.0 Hz.

Only the dual 2 ohm coil is listed. In this airspace the dual 1 ohm goes too dry to recommend sealed; it belongs in a ported box.

Measure the installed height, not the cabinet height: 11.75 tall on its own, 13.50 with the standoffs on the 30 by 15 footprint.

Floor slot is 0.87 times the cone area at the 1.75 standoff, under the 1.0 I like. For hard use, taller feet or front firing.

Ampere's table needed reading carefully: no cone area is printed, so it is derived from their own Vas, Fs and moving mass. Displacement is estimated.

Inserts ship in the kit, not pressed: Ampere prints no bolt circle. Mark from the driver, drill, press. Sealed, so leave the polyfill as it is and run it at 2000 watts or under per driver.

Before you order

Questions

Does this fit the Ampere Audio AA-3.0 12, and will any other 12 inch fit?

The AA-3.0 12, yes, in the dual 2 ohm version. The baffle is cut to 11.12 in, Ampere's published cutout, under the 12.50 in frame. The 10.25 inch motor clears the cabinet with 0.75 inch to spare. Run two of the same coil so the chambers match. This cabinet is listed for the AA-3.0 12 dual 2 ohm only. Ampere's dual 1 ohm version reads Qtc 0.52 in the same airspace, too damped to sound right sealed, so it is not offered in this enclosure.

Any other 12, no. The airspace is engineered around the AA-3.0 12's own Qts and Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

Why 0.83 cubic feet per chamber, and what alignment does it target?

0.83 cubic feet net per chamber on Ampere's published figures: the dual 2 ohm reads Qtc 0.607 with resonance at 43.6 Hz and half power at 52.0 Hz. That is a slightly over-damped alignment: a gentle, early rolloff and tight transients rather than a flat top.

The 10.25 inch mounting depth sets the minimum cabinet height here, so the airspace is what the motor allows rather than a free choice.

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

Ampere rates the AA-3.0 12 at 2000 watts RMS per driver, so target 1400 to 2000 watts RMS per driver at the final load.

This cabinet is for the AA-3.0 12 dual 2 ohm; a matched pair should share a coil. A pair of dual 2 ohm drivers lands on 2 ohms with each woofer's coils in series and the two woofers in parallel, or 8 ohms all in series. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for, so series wiring is the safe default. Confirm your amplifier's minimum stable impedance first.

How tall is this once the standoffs are on?

The cabinet is 11.75 inches tall measured in the down fire position, and that figure excludes the standoffs. The standoffs hold 1.75 inches under the baffle, so plan your space around a finished stack of roughly 13.50 inches.

The footprint is the standard Performance Optimized down fire platform, 30.00 inches wide by 15.00 deep. Height is the only dimension solved to the driver, and here it is the AA-3.0 12's 10.25 inch motor that sets it.

Why two separate chambers instead of one shared volume?

Two drivers sharing one sealed volume load each other: each driver's compression stroke becomes the pressure the other works against, which blurs the alignment either would have alone. A bonded full-height 3/4 inch divider gives each driver its own 0.83 cubic feet and its own polyfill.

It also means a failure in one driver does not unload the other, and the alignment on this page is the alignment in each chamber, not an average across a shared box.

What is the expected low-frequency extension?

Anechoic F3 is 52.0 Hz per chamber. Below Qtc 0.707 the rolloff is gentle and F3 sits above fc, which is what an over-damped sealed box does.

Those figures exclude cabin gain. In a car the cabin's transfer function adds real output below 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 in both chambers as a light wall lining to control internal reflections, and the quantity is chosen so it does not change the acoustic volume.

Do not add more. Packing a sealed box with fill makes it behave as though it were larger, which walks the alignment away from the 0.83 cubic feet per chamber this cabinet was built to.

Is the driver included, and are the threaded inserts installed?

No driver. This is an enclosure only. You receive the cabinet finished in plush black carpet, one side-mounted pre-wired terminal cup to both positions, the polyfill lining already in place, the standoffs, and a threaded insert kit with stainless machine screws.

The inserts ship loose on purpose: Ampere prints no bolt circle for the AA-3.0 12, so you set the driver in the recess, mark its holes, drill and press the inserts. The pair of Ampere Audio AA-3.0 12 is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 12 inch box.

Same series, same size

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