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Performance Optimized · Datasheet

Performance Optimized Sealed 12" Enclosure | Image Dynamics IDQ 12 Single 12" Sealed enclosure

Net volume
1.4 cu ft
Max mounting depth
5.91" (IDQ12 V4) with generous clearance
Cutout
10.87" (276mm), matched to IDQ12 V4
External dimensions
24" x 15" x 10.5"
Buy at Audio Intensity
  • Best For: Single Image Dynamics IDQ12 V4 SQ Builds
  • Tuning: Sealed, Extended SQ Alignment
  • Net Volume: 1.4 cu ft
  • Construction: V-Groove + Dado, Langboard Elite MDF, CNC-Cut in TN

Technical specifications

SeriesProline X Performance Optimized
SKUPO ID 12-S IDQ
Designed ForImage Dynamics IDQ12 V4 subwoofer (D2 or D4)
Enclosure TypeSealed
Net Internal Volume1.4 cu ft
External Dimensions (W x H x D)24" x 15" x 10.5"
Cutout Diameter10.87" (276mm), matched to IDQ12 V4
Driver Mounting Depth Supported5.91" (IDQ12 V4) with generous clearance
Power Handling500 watts RMS (IDQ12 V4)
MaterialLangboard Elite MDF, 3/4"
JoineryPrecision V-groove and dado, CNC-cut on ShopSabre routers
Driver Mounting8/32 threaded inserts with stainless steel machine screws (included)
TerminalProline X ABS/carbon fiber composite cup, stainless hardware, copper ring terminals
Internal Wiring12-gauge OFC, pre-wired
DampingPolyfill pre-installed
Carpet OptionsDark Gray Trunkliner (standard) / Plush Black
Acrylic Insert OptionsBlack, Blue, Red, White, or None
Bundle OptionsBox Only / Add IDQ12 V4 Dual 2-ohm / Add IDQ12 V4 Dual 4-ohm
Built InTullahoma, Tennessee, USA
Warranty1-Year Limited

Performance in this enclosure

Net airspace
1.40
cu ft per chamber
System Qtc
1.02–1.10
sealed
Half power
39.3–39.6
Hz · F3
Xmax at
492
W RMS · no filter
With 25 Hz subsonic
510
W RMS · +4%
Amplifier
375
W RMS recommended
This enclosure holds 1.40 cu ft net per chamber. In it the Image Dynamics IDQ12 V4 runs a system Qtc of 1.02–1.10 with half power at 39.3–39.6 Hz, and the cone reaches its 14.5 mm travel limit at 492 W, above the driver’s 375 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 510 W — +18 W, or 4 percent more power for the same 14.5 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 40.3–43.3
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 D2 43.3 D4 40.3
D2 · EBP 43.3D4 · EBP 40.3
EBP under 50 means a motor that wants a sealed load. The IDQ12 V4 sits at 40.3–43.3, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

1.40 cu ft against a 48.6 L Vas.

α = Vas ÷ Vb = 1.23  ·  Fc = Fs√(α+1) = 51–52 Hz  ·  Qtc = 1.02–1.10
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
D2 · Qtc 1.02, Fc 51 Hz, F3 39.6 HzD4 · Qtc 1.10, Fc 52 Hz, F3 39.3 Hz
The box lifts resonance from 34.0 Hz free-air to 51–52 Hz and half power lands at 39.3–39.6 Hz, anechoic, before any cabin gain. This enclosure ships without a driver, so both coil variants the maker offers are plotted. They do not load the same box the same way.

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

PXmax = 492–502 W unfiltered  →  510–513 W 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 14.5 mm 492 W reaches Xmax here
D2 · 492 W, no filterD4 · 502 W, no filterD2 · 510 W with subsonic at 25 Hz, 24 dB/octD4 · 513 W with subsonic at 25 Hz, 24 dB/octXmax 14.5 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 14.5 mm. Unfiltered that is 492 W, reached first at 37 Hz. It sits above the 375 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 510 W before hitting the same 14.5 mm. That is 4 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs34.00Hzfree-air resonance
Qts0.681 / 0.740D2 / D4
Vas48.57 / 47.22Lequivalent compliance
Sd510.7cm²effective piston area
Xmax14.5mmone-way linear travel
Pe375Wcontinuous RMS
SPL85.7dB1 W / 1 m, derived from T/S

Driver parameters as published by imagedynamicsusa.net. Curves computed against this enclosure’s actual net airspace.

Installer's take

If I could only recommend one subwoofer-and-box combination for a sound quality daily driver, a single IDQ12 V4 in the right sealed enclosure would be on the very short list. The IDQ rewards correct airspace more than almost any driver I work with, and 1.4 cubic feet is a deliberate choice: the extended end of Image Dynamics' sealed window. You trade a hair of box punch for genuinely deeper extension, and the IDQ's motor control keeps the bottom end articulate the whole way down. With an EBP of 40, this driver was never going in a ported box; sealed is its home and this is the airspace. The build details earn their keep. Threaded inserts match the IDQ's bolt pattern, so the driver torques down properly and comes back out cleanly, which matters with the IDQ's field-replaceable cone system. The terminal cup is pre-wired in 12-gauge OFC, so your install is two wires and four machine screws. Pick the coil version around your amplifier. A Dual 4-ohm wired parallel presents 2 ohms, which makes the Wavtech link500.1mini a textbook match at 500 watts. A Dual 2-ohm wired parallel presents 1 ohm, where the Crescendo Revolution 5A1's constant 450 watts is a beautiful SQ pairing, or the link1500.1plus if you want headroom. Either way, clean power matters more to the IDQ than big numbers. At 24 inches wide this box fits most trunks sideways with room left over. Set the subsonic sensibly, keep the gain honest, and a single IDQ12 in this enclosure will blend into a front stage so well that passengers look for the sub in the wrong places. That is the IDQ doing its job. -Scott

Questions

What subwoofer is the Performance Optimized Sealed 12 enclosure designed for?

The Performance Optimized Sealed 12 (PO ID 12-S IDQ) is engineered specifically for the Image Dynamics IDQ12 V4 subwoofer, in either Dual 2-ohm or Dual 4-ohm voice coil configuration. The 1.4 cubic foot net volume, 10.87 inch baffle cutout, and 8/32 threaded insert mounting pattern are all matched to the IDQ12 V4's published specifications rather than averaged across a class of 12-inch drivers.

Why 1.4 cubic feet for the IDQ12 V4?

Image Dynamics rates the IDQ12 V4 for sealed enclosures from 0.6 to 1.8 cubic feet, with 1.0 to 1.25 as the balanced optimum. The 1.4 cubic foot alignment sits deliberately in the extended portion of that window, trading a small amount of box punch for deeper bass extension while preserving the transient accuracy the IDQ Series is known for. Polyfill comes pre-installed, so the enclosure performs as designed out of the box.

Will the Image Dynamics IDQ12 V4 bolt directly into this enclosure?

Yes. The baffle carries 8/32 threaded inserts matched to the IDQ12 V4's published mounting hole pattern, and stainless steel machine screws are included. The 10.87 inch cutout matches the IDQ12 V4's specified cutout diameter, and the enclosure's 10.5 inch depth clears the driver's 5.91 inch mounting depth with room to spare.

How do I wire a single IDQ12 V4 and what final impedance will I get?

It depends on the voice coil version. An IDQ12 V4 Dual 2-ohm wires to 1 ohm with the coils in parallel or 4 ohms in series. An IDQ12 V4 Dual 4-ohm wires to 2 ohms in parallel or 8 ohms in series. The enclosure's Proline X terminal cup is pre-wired with 12-gauge OFC, so you connect the amplifier leads at the cup and set the coil wiring at the driver.

What amplifier should I use with the IDQ12 V4 in this enclosure?

The IDQ12 V4 handles 500 watts RMS, and clean power in the 300 to 500 watt range brings out its best. A Dual 4-ohm driver wired to 2 ohms pairs perfectly with the Wavtech link500.1mini at 500 watts. A Dual 2-ohm driver wired to 1 ohm pairs with the Crescendo Revolution 5A1, which delivers a constant 450 watts at 1 ohm, or the Wavtech link1500.1plus for additional headroom.

What are the carpet and acrylic insert options?

The acrylic insert is cosmetic and does not affect acoustic performance.

Should I choose this single 12 enclosure or the dual 12 version?

Choose by output needs and space. The single Performance Optimized Sealed 12 (24 by 15 by 10.5 inches, 1.4 cubic feet) with one IDQ12 V4 suits most sound quality daily drivers and preserves trunk space. The Performance Optimized Dual Sealed 12 Enclosure (30 by 15 by 15 inches, approximately 2.8 cubic feet common chamber) doubles cone area and power handling to 1000 watts RMS for higher effortless output at the same listening levels. Both run the same 1.4 cubic feet per driver, so the sonic character matches; the dual simply does it with more authority.

Can I buy this enclosure loaded with the subwoofer?

Yes. The Performance Optimized Sealed 12 is available as the box only, or bundled with an Image Dynamics IDQ12 V4 in your choice of Dual 2-ohm or Dual 4-ohm. Bundled orders ship together from our facility in Tullahoma, Tennessee, and the enclosure carries a 1-year limited warranty.

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