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Performance Optimized · Datasheet

Performance Optimized Down Fire Wide Sealed 12" Enclosure NVX VCW12v3 · Single 12" Sealed enclosure

Net volume
1.546 cu ft after the brace and 0.15 cu ft displacement
External dimensions
41 in W × 8.375 in in the down fire position H × 14 in D
Front baffle
1.5 in double baffle, outer layer machined as a flush recess
Buy at Audio IntensityFactory-direct, ships from Tullahoma
  • Alignment: 1.546 cu ft net. VCW122v3 (D2): Qtc 0.563, Fc 35.2 Hz, F3 46.4 Hz; VCW124v3 (D4): Qtc 0.563, Fc 35.2 Hz, F3 46.4 Hz
  • Down Fire Wide: 41"W x 14"D x 8.375"H in down fire position, excludes standoffs, square corners
  • Versus the standard 30 x 15: 8.35 in tall and 1.15 cu ft net there, 8.375 in tall and 1.546 cu ft net here
  • Driver: NVX VCW12v3 (VCW122v3 D2 or VCW124v3 D4), 1200 W RMS, 23 mm Xmax, 6.85 in mounting depth
  • Standoffs: Included, 1.75 in, shipped uninstalled. Installed height 10.125 in

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Down Fire Wide
Compatible DriverNVX VCW12v3. Direct fit
Enclosure TypeSealed, down fire, floor coupled
Intended FitmentSpaces where height or depth is the limit and 41 in of run is available
Chamber ConfigurationSingle chamber, windowed U-brace, one side-mounted terminal cup
External Width41 in
External Depth14 in
External Height8.375 in in the down fire position, excludes standoffs
Installed Height10.125 in including the 1.75 in standoffs
Internal Volume, Gross1.71 cu ft
Internal Volume, Net1.546 cu ft after the brace and 0.15 cu ft displacement
Height Set ByDriver clearance: 0.75 in above the 6.85 in motor
Alignment, VCW122v3 (D2)Qtc 0.563, Fc 35.2 Hz, F3 46.4 Hz anechoic
Alignment, VCW124v3 (D4)Qtc 0.563, Fc 35.2 Hz, F3 46.4 Hz anechoic
Comparison, Standard 30 x 158.35 in tall, 1.15 cu ft net. Wide format is 8.375 in tall with 1.546 cu ft net
Woofer Opening11.18 in, NVX's published cutout
Frame Outer Diameter12.64 in, NVX published
Bolt Circle11.63 in, NVX published; threaded inserts pre-installed
Driver Displacement0.150 cu ft, NVX published
VCW122v3 (D2) Fs / Qts / Qes / Qms / Vas25.05 Hz / 0.400 / 0.434 / 5.12 / 42.90 L
VCW124v3 (D4) Fs / Qts / Qes / Qms / Vas25.05 Hz / 0.400 / 0.434 / 5.12 / 42.90 L (NVX product page column)
Driver Sd530 cm2, published by NVX
Xmax23 mm one way, NVX spec
Driver Power Handling1200 W RMS, NVX spec
Floor Slot0.75 times the cone area at the 1.75 in standoff
Parameter SourceNVX VCW122v3 / VCW124v3 owner's manual and nvx.com product pages
MaterialLangboard Elite 3/4 in MDF
ConstructionShopSabre CNC, V-groove and dado joinery
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Internal BracingWindowed U-brace, dadoed to the shell
Corner ProfileSquare, Down Fire series standard
Driver MountingThreaded inserts pressed on NVX's published 11.63 inch bolt circle, stainless machine screws included
Terminal CupOne Proline X ABS and carbon fiber composite, side mounted, pre-wired 12 gauge OFC
StandoffsIncluded, 1.75 in, shipped uninstalled
DampingLight polyfill wall lining, does not alter acoustic volume
CarpetPlush Black
Bundle OptionsEnclosure only, bring your own NVX VCW12v3
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.546
cu ft
System Qtc
0.56
sealed
Half power
46.4
Hz · F3
Xmax at
978
W RMS · no filter
With 25 Hz subsonic
1929
W RMS · +97%
Amplifier
1200
W RMS recommended
This enclosure holds 1.546 cu ft net . In it the NVX VCW12v3 runs a system Qtc of 0.56 with half power at 46.4 Hz, and the cone reaches its 23.0 mm travel limit at 978 W, below the driver’s 1200 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 1929 W — +951 W, or 97 percent more power for the same 23.0 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 57.7
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 D2 57.7 D4 57.7
D2 · EBP 57.7D4 · EBP 57.7
At 57.7 the VCW12v3 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

1.546 cu ft against a 42.9 L Vas.

α = Vas ÷ Vb = 0.98  ·  Fc = Fs√(α+1) = 35 Hz  ·  Qtc = 0.56
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
D2 · Qtc 0.56, Fc 35 Hz, F3 46.4 HzD4 · Qtc 0.56, Fc 35 Hz, F3 46.4 Hz
The box lifts resonance from 25.1 Hz free-air to 35 Hz and half power lands at 46.4 Hz, anechoic, before any cabin gain. Figures are NVX’s published VCW12v3 parameters from its owner’s manual and product pages, displacement included (0.150 cubic feet). One cabinet serves both coils; both are plotted.

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

PXmax = 978 W unfiltered  →  1929 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 8 16 24 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 23.0 mm 978 W reaches Xmax here
D2 · 978 W, no filterD4 · 978 W, no filterD2 · 1929 W with subsonic at 25 Hz, 24 dB/octD4 · 1929 W with subsonic at 25 Hz, 24 dB/octXmax 23.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 23.0 mm. Unfiltered that is 978 W, reached first at 20 Hz. It sits under the 1200 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 1929 W before hitting the same 23.0 mm. That is 97 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs25.05Hzfree-air resonance
Qts0.400 / 0.400D2 / D4
Vas42.90 / 42.90Lequivalent compliance
Sd530.0cm²effective piston area
Xmax23mmone-way linear travel
Pe1200Wcontinuous RMS
SPL83.8dB1 W / 1 m, derived from T/S

Driver parameters as published by NVX VCW12v3 owner’s manual. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Same VCW12v3 as the standard 30 by 15 box, laid out 41 by 14. One inch shallower, 11 inches longer, and the same height to within a fraction, 8.375 against 8.35, because the motor sets both. Measure all three dimensions before choosing between them.

Height here is set by the 6.85 inch motor, not the airspace: 0.75 inch above the motor is the floor, and at 41 by 14 that already buys 1.546 cubic feet net against the 1.15 the standard box was built to. That is a clearance fact, not a tuning target. More air lowers Qtc, which is the safe direction.

Alignment: VCW122v3 (D2) at Qtc 0.563, F3 46.4 Hz; VCW124v3 (D4) at Qtc 0.563, F3 46.4 Hz.

Below 0.6 that is a well-damped, dry alignment. If the customer wants punch and has the length budget, sell them the standard box.

Cut is 11.18, NVX's own figure, and the inserts are already pressed on their 11.63 bolt circle. Floor slot is 0.75 times the cone area at the 1.75 standoff; taller feet help if the floor allows. Leave the polyfill as it is and run it at 1200 watts or under.

Before you order

Questions

Why is this cabinet 41 inches wide instead of 30?

Because it trades length for depth and height. The standard single Down Fire platform is 30 wide by 15 deep; this one is 14 deep, 1 inch shallower, and runs 41 inches long to put the airspace along the length instead.

On this driver the motor sets the minimum height of both boxes, so it stands 8.375 inches against 8.35 and the extra length becomes extra airspace. A 12 inch frame needs about 13 inches of baffle, so 14 is as shallow as a 12 can go.

How does this compare to the standard 30 x 15 VCW12v3 enclosure?

The standard box is 30 by 15 by 8.35 inches and holds 1.15 cubic feet net. This one is 41 by 14 by 8.375 inches and holds 1.546 cubic feet net.

Here the wide box holds more air because its height is set by motor clearance, not by an airspace target. More air lowers Qtc, the safe direction. Choose the standard box when length is limited, this one when depth is the limit and you have 41 inches of run.

What alignment does this enclosure produce?

At 1.546 cubic feet net the result is VCW122v3 (D2): Qtc 0.563, Fc 35.2 Hz, F3 46.4 Hz; VCW124v3 (D4): Qtc 0.563, Fc 35.2 Hz, F3 46.4 Hz, calculated from the driver's own published Thiele-Small parameters.

That is well under the 0.707 maximally flat reference: a well-damped, dry alignment with a slow, early rolloff. The figures are anechoic; in a car, cabin gain adds real output below 50 Hz, so in-vehicle response runs deeper.

If you want more punch, the standard 30 by 15 box is the pick.

How much power should I run, and how do I wire it?

NVX rates the VCW12v3 at 1200 watts RMS. The VCW122v3 (D2) wires to 4 ohms with its coils in series or 1 ohm in parallel. The VCW124v3 (D4) wires to 8 ohms in series or 2 ohms in parallel. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for; series wiring is the safe default. Confirm the load against your amplifier's minimum stable impedance before powering the system.

How tall is this once the standoffs are on?

The cabinet is 8.375 inches tall measured in the down fire position, excluding standoffs. The standoffs hold 1.75 inches under the baffle, so plan your space around 10.125 inches installed.

The standoffs ship uninstalled, so you can place them to suit your floor, or leave them off and run the cabinet front firing or up firing.

Where is the terminal cup located on a down fire enclosure?

Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup regardless of alignment, whether standard, wedge, or down fire. On this cabinet that keeps the connection accessible with the enclosure installed, since the baffle faces the floor. The cup is our Proline X ABS and carbon fiber composite unit with stainless hardware, copper ring terminals, and pre-wired 12 gauge OFC.

How is this enclosure built?

V-groove and dado joinery, CNC cut on ShopSabre routers from Langboard Elite MDF, with square corners as the Down Fire standard. Every panel joint is a machined interlocking groove that locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling.

The 1.5 inch double baffle has its outer layer machined as a flush recess so the driver bolts to the inner layer, and a windowed U-brace stiffens the long panels. Polyfill is installed as a light wall lining; do not add more, since packing a sealed box makes it act larger and moves the alignment. Assembled and inspected in Tullahoma, Tennessee.

Is the NVX VCW12v3 included with this enclosure?

No. This listing is for the enclosure only. Bring your own NVX VCW12v3. The cutout and cabinet height are cut direct fit for this driver. Threaded inserts are pressed on NVX's published 11.63 inch bolt circle and stainless machine screws are included.

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