Helix W12 Competition (1x4 Ohm)
12″ subwoofer · 4 Ω · 350 W RMS
| Source | web.archive.org · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | complete |
| Mounting dimensions | 1 of 4 — missing: cutout, frame outer diameter, magnet diameter; the designer will use an estimate |
Recommended box
For a sedan, one sub, 350 W. It’s the same math as the designer’s step-by-step mode, where you can fit the box to your space, vehicle and amp and get plans, a cut sheet and DXF.
Sealed
smaller, tighter| Bass character (Qtc) | Flat and accurate · 0.78 |
|---|---|
| Fc | 55 Hz |
| F3 (−3 dB, no cabin gain) | 54 Hz |
| Example box (outside) | 14 3/16″ × 14 3/16″ × 10 7/16″ |
Ported
deeper, louder| Tuning (Fb) | 30 Hz |
|---|---|
| Port | slot 1 9/16 × 14 5/16″, 24 3/8″ long |
| Port velocity at 350 W | 61 ft/s |
| F3 (−3 dB, no cabin gain) | 29 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 13 1/16″ |
Deeper: 2.01 ft³ (57 L) tuned to 29 Hz, 31 1/2″ × 15 3/4″ × 12 3/16″ outside — a bigger box with flatter deep bass. Open in the calculator
Projects with this subwoofer
Boxes that users designed and published: plans, cut sheet and response graph.
Thiele/Small parameters
| Size | 12″ |
|---|---|
| Voice coils | 4 Ω |
| RMS power | 350 W |
| Fs | 21.4 Hz |
| Qts | 0.30 |
| Qes | 0.33 |
| Qms | 3.59 |
| Vas | 4.19 ft³ |
| Re | 3.2 Ω |
|---|---|
| Sd | 79.7 in² |
| Xmax | 0.43″ |
| Vd | 34.5 in³ calc. |
| Mms | 175 g calc. |
| BL | 15.1 T·m calc. |
| EBP | 65 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 87.5 dB calc. |
Mounting dimensions
| Cutout diameter | ≈ 11 1/8″ |
|---|---|
| Mounting depth | 5 1/2″ |
Cone area (Sd) calculated from Fs, Vas and Mms: 79.8 in².
“≈” means the value isn’t in the spec sheet and a typical value for the size is used; “calc.” means it’s calculated from the published parameters. Check the manufacturer’s spec sheet before you build.
Data sources
- web.archive.org/web/20060226043907/http://www.audiotec-fischer.com:80/pdfs/Woofe
- web.archive.org/web/20060311213645/http://www.audiotec-fischer.com/pdfs/HelixPro
- web.archive.org/web/20061016233435/http://www.audiotec-fischer.com/pdfs/Helix%20
Other Helix 12″ models
- Helix DB 12 Deep Blue (1x4 Ohm) 12″ · 4 Ω
- Helix IK S12-DVC2 (2x2 Ohm) 12″ · dual 2 Ω
- Helix IK S12-SVC2 (1x2 Ohm) 12″ · 2 Ω
- Helix IK W12-DVC2 (2x2 Ohm) 12″ · dual 2 Ω
- Helix IK W12-SVC2 (1x2 Ohm) 12″ · 2 Ω
- Helix IQ W12-DVC2 (2x2 Ohm) 12″ · dual 2 Ω
- Helix K 12W-SVC2 (1x2 Ohm) 12″ · 2 Ω
- Helix Q 12W (2x2 Ohm) 12″ · dual 2 Ω
Similar 12″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Ground Zero GZHW 12SPL-D2 FLAT (2x2 Ohm) 0.78 ft³ sealed · 2.51 ft³ ported
- Orion 2NT 12 SVC 0.71 ft³ sealed · 2.30 ft³ ported
- Kenwood KFC-XW1241HP 0.71 ft³ sealed · 1.34 ft³ ported
- Magnat Destructor 1200 0.92 ft³ sealed · 2.26 ft³ ported
- Mac Audio STX 12 Reference 0.71 ft³ sealed · 2.26 ft³ ported
- SPL Dynamics V-12S4 0.81 ft³ sealed · 2.44 ft³ ported
FAQ
What box does the Helix W12 Competition (1x4 Ohm) need?
Recommended net volume: 0.74 ft³ sealed, 2.37 ft³ ported tuned to 30 Hz — for one sub in a sedan at 350 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Helix W12 Competition (1x4 Ohm) Thiele/Small specs?
Fs 21.4 Hz, Qts 0.30, Vas 4.19 ft³, Xmax 0.43″, Sd 79.7 in².
What is the Helix W12 Competition (1x4 Ohm) mounting depth?
Mounting depth is 5 1/2″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Helix W12 Competition (1x4 Ohm) handle and how do I wire it?
RMS power rating: 350 W. Wiring for several subs and amp power — in the wiring calculator.