




Performance Optimized · Datasheet
Helix IQ W12 Box: Sealed 12" Wedge Enclosure Single 12" Sealed enclosure
- Net volume
- 1.17 to 2.30 cu ft, by setting
- Tuning
- No Added Mass, +1 Mass Ring, +2 Mass Rings. Each is a different cabinet, cut to order
- Max mounting depth
- 5.70 in required by the driver
- Cutout
- 11.0600 in, same at every setting
- External dimensions
- 25.90 to 29.50 in across the settings W × 15 in at the seat face H × 12.60 to 17.06 in at the base D
- Front baffle
- 1.5 in, double baffle
- Best For: Helix IQ W12 Trunk-Fit Builds
- Net Volume: 1.17 to 2.30 cu ft by Tuning Mass setting
- Alignment: Qtc 0.689 to 0.707, fc 36.0 to 51.7 Hz, F3 36.0 to 53.1 Hz anechoic
- Tuning Mass: 3 settings offered, cut and built to order
- Driver Match: Helix IQ W12, DVC2
- Impedance: 1 ohm parallel or 4 ohm series
- Construction: Rear-Firing Wedge | V-Groove/Dado | Double 1.5" Baffle | Threaded Inserts
Spec of record
Technical specifications
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Wedge |
| Compatible Driver | Helix IQ W12 DVC2, quantity 1. Direct fit |
| Configuration | Single 12 inch, single chamber sealed wedge |
| Tuning Mass Settings Offered | No Added Mass, +1 Mass Ring, +2 Mass Rings. Each is a different cabinet, cut to order |
| Build | Cut and built to order. Nothing is pre-cut |
| Mounting Position | Trunk or cargo area, tall face against the rear seat back |
| Firing Direction | Rearward into the trunk. Not a down fire design, no feet included |
| External Width | 25.90 to 29.50 in across the settings |
| External Height | 15 in at the seat face |
| External Depth | 12.60 to 17.06 in at the base, 7.14 to 11.60 in at the top |
| Internal Volume, Gross | 1.26 to 2.39 cu ft, by setting |
| Internal Volume, Net Acoustic | 1.17 to 2.30 cu ft, by setting |
| Alignment | Qtc 0.689 to 0.707, fc 36.0 to 51.7 Hz, F3 36.0 to 53.1 Hz anechoic, by setting |
| Helix Recommended Volume | 33 to 65 litres net across the settings offered |
| Driver Cutout | 11.0600 in, same at every setting |
| Driver Mounting Depth | 5.70 in required by the driver |
| Power Handling | 750 watts RMS |
| Impedance | DVC2, dual 2 ohm: 1 ohm parallel or 4 ohm series per driver |
| Xmax | 12 mm one way |
| Material | Langboard Elite MDF |
| Construction | CNC cut, V-groove and dado joinery |
| Panel Thickness | 0.75 in |
| Front Baffle | 1.5 in, double baffle |
| Internal Bracing | Internal brace |
| Driver Mounting | Threaded inserts at every mounting location, stainless machine screws included |
| Terminal Cups | One Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC |
| Damping | Light polyfill wall lining, does not alter acoustic volume |
| Carpet | Plush black |
| Weight | 42.5 to 55.1 lb depending on setting |
| Warranty | 1 Year Limited |
| Built In | Tullahoma, Tennessee |
Modelled response
Performance in this enclosure
01Is it a sealed driver?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
1.17–2.30 cu ft against a 35.0 L Vas.
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 12.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 36.00 / 32.00 / 29.00 | Hz | free-air resonance |
| Qts | 0.480 / 0.530 / 0.570 | 0 TM / +1 TM / +2 TM | |
| Vas | 35.00 / 35.00 / 35.00 | L | equivalent compliance |
| Sd | 515.0 | cm² | effective piston area |
| Xmax | 12 | mm | one-way linear travel |
| Pe | 750 | W | continuous RMS |
| SPL | 86.7 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by audiotec-fischer.de and the HELIX IQ datasheet. Curves computed against this enclosure’s actual net airspace.
From the shop floor
Installer's take
1.17 to 2.30 cubic feet net at Qtc 0.689 to 0.707 and F3 36.0 to 53.1 Hz anechoic, depending on which Tuning Mass setting you order. Every figure is computed from Helix's published Thiele-Small for that setting.
The IQ series carries Helix's Tuning Mass System: bolt-on weights that thread onto the cone assembly and let one driver run several alignments. Each weight raises moving mass, which drops free-air resonance and raises the driver's total Q, and Helix publishes a different recommended sealed volume for every setting to keep the system in hand. This cabinet is offered in no added mass, +1 mass ring and +2 mass rings, 33 to 65 litres of Helix's own recommended volume, and across those the system Q works out at 0.69 at the base setting and 0.71 at the top of the range offered. What does not change is compliance, and therefore Vas, because mass and spring rate are independent.
The IQ W12 ships with three weights. The top setting, all three fitted, is not offered as a listed size here; call or text 931-563-5151 if that is the alignment you want and we will quote the cabinet for it.
Every one of these is cut and built to order. Nothing is pre-cut and nothing sits on a shelf waiting for a Tuning Mass setting to be chosen, because each setting is a different cabinet rather than a label on one. Pick the setting you intend to run and the panels are cut to it.
On the F3 figures: Helix prints a lower limiting frequency for every Tuning Mass setting, and ours agree with theirs to within 1.3 Hz at every setting offered here. That is worth stating because it is not true of every Helix line. The IK datasheets quote their figure with a recommended DSP highpass applied and read several hertz optimistic against the raw sealed response; the IQ sheets carry no filter recommendation and their numbers reconcile with the anechoic math. Both F3 columns in the table above are anechoic and exclude cabin gain.
On impedance: The IQ series ships in one coil version, the DVC2: two 2 ohm coils on one 63 mm former. In parallel that is 1 ohm, in series 4 ohms. Pick the one your amplifier is rated for, and note that 1 ohm needs an amplifier that says so.
Measure before you order, and measure for the setting you actually want. These range from 25.90 to 29.50 inches wide, 12.60 to 17.06 deep at the base and 15 tall.
Before you order
Questions
What is the Tuning Mass System and which setting should I order?
The IQ series carries Helix's Tuning Mass System: bolt-on weights that thread onto the cone assembly and let one driver run several alignments. Each weight raises moving mass, which drops free-air resonance and raises the driver's total Q, and Helix publishes a different recommended sealed volume for every setting to keep the system in hand. This cabinet is offered in no added mass, +1 mass ring and +2 mass rings, 33 to 65 litres of Helix's own recommended volume, and across those the system Q works out at 0.69 at the base setting and 0.71 at the top of the range offered. What does not change is compliance, and therefore Vas, because mass and spring rate are independent. Fewer weights give a smaller cabinet, a higher resonance and a drier, faster presentation; more weights give a bigger cabinet and deeper extension. Order the setting you intend to run, because the cabinet is cut to it. The IQ W12 ships with three weights. The top setting, all three fitted, is not offered as a listed size here; call or text 931-563-5151 if that is the alignment you want and we will quote the cabinet for it. Every one of these is cut and built to order. Nothing is pre-cut and nothing sits on a shelf waiting for a Tuning Mass setting to be chosen, because each setting is a different cabinet rather than a label on one. Pick the setting you intend to run and the panels are cut to it.
Why does each setting get a different volume?
Because Helix publishes a different recommended sealed volume for each one, and the reason is physics rather than preference. Adding mass drops the driver's free air resonance and raises its total Q, so holding system Q near reference means growing the box. Compliance does not change, so Vas stays at 35 litres throughout. The table on this page lists what we build for each setting.
What amplifier power should I run, and what impedance?
The Helix IQ W12 is rated 750 watts RMS each, so 750, and that does not change with the Tuning Mass setting. The IQ series ships in one coil version, the DVC2: two 2 ohm coils on one 63 mm former. In parallel that is 1 ohm, in series 4 ohms. Pick the one your amplifier is rated for, and note that 1 ohm needs an amplifier that says so. Aim for roughly 525 to 750 watts at whichever impedance you wire to.
Does your F3 agree with the figure on Helix's datasheet?
Helix prints a lower limiting frequency for every Tuning Mass setting, and ours agree with theirs to within 1.3 Hz at every setting offered here. That is worth stating because it is not true of every Helix line. The IK datasheets quote their figure with a recommended DSP highpass applied and read several hertz optimistic against the raw sealed response; the IQ sheets carry no filter recommendation and their numbers reconcile with the anechoic math. Both F3 columns in the table above are anechoic and exclude cabin gain.
Why this shape?
A rectangular box of this volume wastes the triangle of space a leaning rear seat creates. The wedge takes the same air and puts it where the car actually has room.
What is the expected low-frequency extension?
Half power lands between 36.0 and 53.1 Hz depending on the setting anechoic, before any cabin gain, with Qtc from 0.689 to 0.707. These figures exclude cabin gain, which in most vehicles adds real output below 40 Hz, and they exclude any DSP you choose to run.
Do I need to add polyfill or damping?
No. Polyfill is already installed as a light wall lining and the quantity is chosen for the cabinet you ordered, so it does not change the acoustic volume. Do not add more.
Is the driver included, and how long does it take to build?
No. This is an enclosure only, and the Tuning Mass weights come with the driver from Helix rather than with the cabinet. You receive the box 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. Because every setting is a different cabinet, nothing is cut ahead of time and these are built to order. Call or text 931-563-5151 for current lead time.
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