Proline X PO 12-S W GB12 sealed wedge, front baffle with gloss black insert and pre-wired leads, 21.5 by 15 inches.Proline X PO 12-S W GB12 sealed wedge, side profile with recessed terminal cup, 13.5 inch base, 15 inches tall.

Performance Optimized · Datasheet

Performance Optimized Wedge Sealed 12" Enclosure | Audiofrog GB12 Single 12" Sealed enclosure

Net volume
1.00 cu ft
Max mounting depth
7.154 in available, 6.654 in required by the driver
Cutout
11.0630 in
External dimensions
21.45 in W × 15 in at the seat face H × 13.55 in at the base D
Front baffle
1.5 in, double baffle
Buy at Audio Intensity
  • Best For: Audiofrog GB12 Trunk-Fit Builds
  • Net Volume: 1.00 cu ft (1.16 cu ft Gross)
  • Alignment: Qtc 0.851 to 0.883, fc 51.2 Hz, F3 42.9 to 44.0 Hz
  • Driver Match: Audiofrog GB12 (GB12D2 or GB12D4)
  • Impedance: Switch selected, 1 or 4 ohms per driver on the D2, 2 or 8 on the D4
  • Construction: Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | Threaded Inserts

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge
Compatible DriverAudiofrog GB12, quantity 1. Direct fit
ConfigurationSingle 12 inch, single chamber sealed wedge
Mounting PositionTrunk or cargo area, tall face against the rear seat back
Firing DirectionRearward into the trunk. Not a down fire design, no feet included
External Width21.45 in
External Height15 in at the seat face
External Depth13.55 in at the base, tapering to 8.10 in at the top
Internal Volume, Gross1.16 cu ft
Internal Volume, Net Acoustic1.00 cu ft
AlignmentQtc 0.851 to 0.883, fc 51.2 Hz, F3 42.9 to 44.0 Hz anechoic
Driver Cutout11.0630 in
Driver Mounting Depth7.154 in available, 6.654 in required by the driver
Power Handling500 watts RMS
ImpedanceSwitch selected on the driver. D2 selects 1 or 4 ohms, D4 selects 2 or 8
Xmax17.6 mm one way on the D2, 19 mm on the D4
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery
Panel Thickness0.75 in
Front Baffle1.5 in, double baffle
Internal BracingInternal brace
Driver MountingThreaded inserts at every mounting location, stainless machine screws included
Terminal CupsOne Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC
DampingLight polyfill wall lining, does not alter acoustic volume
CarpetPlush black
Weight30.3 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Performance in this enclosure

Net airspace
1.00
cu ft per chamber
System Qtc
0.85–0.88
sealed
Half power
42.9–44.0
Hz · F3
Xmax at
773
W RMS · no filter
With 25 Hz subsonic
831
W RMS · +8%
Amplifier
500
W RMS recommended
This enclosure holds 1.00 cu ft net per chamber. In it the Audiofrog GB12 runs a system Qtc of 0.85–0.88 with half power at 42.9–44.0 Hz, and the cone reaches its 17.6 mm travel limit at 773 W, above the driver’s 500 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 831 W — +58 W, or 8 percent more power for the same 17.6 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 54.6–56.7
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 D2 56.7 D4 54.6
D2 · EBP 56.7D4 · EBP 54.6
At 54.6–56.7 the GB12 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

1.00 cu ft against a 57.0 L Vas.

α = Vas ÷ Vb = 2.01  ·  Fc = Fs√(α+1) = 51 Hz  ·  Qtc = 0.85–0.88
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
D2 · Qtc 0.85, Fc 51 Hz, F3 44.0 HzD4 · Qtc 0.88, Fc 51 Hz, F3 42.9 Hz
The box lifts resonance from 28.4–29.5 Hz free-air to 51 Hz and half power lands at 42.9–44.0 Hz, anechoic, before any cabin gain. The single and dual versions of this enclosure hold the same volume per chamber, so these numbers describe both. Audiofrog publishes a different free-air resonance and compliance for each coil variant rather than one shared pair, so both are carried here rather than averaged.

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

PXmax = 773–801 W unfiltered  →  831–877 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 4 8 12 16 20 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 17.6 mm 773 W reaches Xmax here
D2 · 801 W, no filterD4 · 773 W, no filterD2 · 877 W with subsonic at 25 Hz, 24 dB/octD4 · 831 W with subsonic at 25 Hz, 24 dB/octXmax 17.6 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 17.6 mm. Unfiltered that is 773 W, reached first at 31 Hz. It sits above the 500 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 831 W before hitting the same 17.6 mm. That is 8 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs29.50 / 28.40Hzfree-air resonance
Qts0.490 / 0.490D2 / D4
Vas57.00 / 63.70Lequivalent compliance
Sd510.7cm²effective piston area
Xmax17.6mmone-way linear travel, D2 coil. The D4 coil is rated 19 mm on the same cone; the smaller figure is plotted so the power shown is conservative for both.
Pe500Wcontinuous RMS
SPL86.3dB1 W / 1 m, derived from T/S

Driver parameters as published by audiofrog.com and the GB Series Subwoofer Manual. Curves computed against this enclosure’s actual net airspace.

Installer's take

1.00 cubic feet net. That is Audiofrog's own recommended sealed volume for the GB12, 28.3 liters in their documentation, and theirs is a net figure exactly as ours is: their own sealed drawing works out to that volume only after the basket displacement comes off. Qtc 0.851 to 0.883 and F3 42.9 to 44.0 Hz anechoic, computed from Audiofrog's published Thiele-Small.

Read the impedance section before you mount anything. The GB series does not bring its coils out to the terminals. Each driver carries an impedance selection switch: the D2 version selects 1 or 4 ohms and the D4 version selects 2 or 8. Set it before you mount the driver, because the switch faces the motor and the baffle covers it once the driver is in. Pick the position your amplifier is happiest driving; there is no wiring change either way.

The dual version of this cabinet holds the same 1.00 cubic feet per chamber, so both publish the same alignment.

Measure the base depth. This cabinet is 13.55 inches deep at the trunk floor, 8.10 at the top, and 21.45 wide.

Questions

Will this enclosure fit both the GB12D2 and the GB12D4?

Yes. The two coil versions share a frame, a 11.0630 in cutout and the same 6.654 in mounting depth, so the cabinet fits either. They differ electrically and slightly in excursion, 17.6 mm one way on the D2 against 19 mm on the D4, but nothing about the enclosure changes.

Why 1.00 cubic feet net?

1.00 cubic feet net. That is Audiofrog's own recommended sealed volume for the GB12, 28.3 liters in their documentation, and theirs is a net figure exactly as ours is: their own sealed drawing works out to that volume only after the basket displacement comes off. Qtc lands at 0.851 to 0.883 depending on which coil version you fit, with system resonance at 51.2 Hz. That is a moderately damped alignment rather than a textbook 0.707: it trades a little transient dryness for a slight lift through the midbass, which is the voicing Audiofrog designed the box recommendation around. Each chamber is 1.16 cu ft gross before the driver's 0.147 cu ft of basket displacement.

What amplifier power should I run, and what impedance?

The Audiofrog GB12 is rated 500 watts RMS. The GB series does not bring its coils out to the terminals. Each driver carries an impedance selection switch: the D2 version selects 1 or 4 ohms and the D4 version selects 2 or 8. Set it before you mount the driver, because the switch faces the motor and the baffle covers it once the driver is in. Pick the position your amplifier is happiest driving; there is no wiring change either way. Aim for roughly 350 to 500 watts at whichever impedance you select.

How does a wedge enclosure improve the sound in a trunk installation?

The angled seat-side face matches the roughly 20 degree lean of a factory rear seat, so the cabinet sits flat against it instead of leaving a wasted triangle. The vertical trunk-lid-side face carries the driver, firing rearward into the trunk cavity.

Why a rear-firing wedge instead of a plain box?

A rectangular box of this volume wastes the triangle of space a leaning rear seat creates, and firing into the trunk lid rather than at the seat back gives the cabin a smoother path to the passengers. The wedge takes the same air volume and puts it where the car actually has room.

What is the expected low-frequency extension?

Half power lands at 42.9 to 44.0 Hz anechoic, before any cabin gain. Qtc is 0.851 to 0.883. These figures exclude cabin gain, which in most vehicles adds real output below 40 Hz. Audiofrog rates the GB12 itself down to 22 Hz.

Do I need to add polyfill or damping?

No. Polyfill is already installed as a light wall lining and the quantity is chosen so it does not change the acoustic volume. Do not add more.

Is the driver included?

No. This is an enclosure only. You receive the cabinet finished in plush black carpet, with threaded inserts at the driver position, stainless machine screws, one side-mounted pre-wired terminal cup and the polyfill lining already installed.

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