VM Audio ECW120
12″ subwoofer · dual 4 Ω · 1,500 W RMS
| Source | web.archive.org · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | not in the spec sheet: Xmax — typical value for the size used |
| Mounting dimensions | 2 of 4 — missing: frame outer diameter, magnet diameter; the designer will use an estimate |
Recommended box
For a sedan, one sub, 1,500 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 · 0.73 |
|---|---|
| Fc | 59 Hz |
| F3 (−3 dB, no cabin gain) | 60 Hz |
| Example box (outside) | 14 3/16″ × 14 3/16″ × 10 5/8″ |
Ported
deeper, louder| Tuning (Fb) | 35 Hz |
|---|---|
| Port | slot 1 9/16 × 14 5/16″, 38 5/16″ long |
| Port velocity at 1,500 W | 92 ft/s |
| F3 (−3 dB, no cabin gain) | 35 Hz |
| Example box (outside) | 18 3/8″ × 15 3/4″ × 15 3/8″ |
At 1,500 W this example’s port will be noisy: air speed 92 ft/s, while the limit is 82 ft/s. It stays quiet up to about 1,150 W. Full power needs a port of at least 25.2 in², which means a bigger box than this example — size it in the designer.
Open ported box in designerDeeper: 1.84 ft³ (52 L) tuned to 34 Hz, 31 1/2″ × 15 3/4″ × 14 3/4″ 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 | dual 4 Ω |
| RMS power | 1,500 W |
| Fs | 38 Hz |
| Qts | 0.47 |
| Qes | 0.53 |
| Qms | 4.3 |
| Vas | 1.05 ft³ |
| Re (one coil) | 3.6 Ω |
|---|---|
| Sd | 72.1 in² |
| Xmax | ≈ 0.39″ |
| Mms | 181 g calc. |
| BL | 17.1 T·m calc. |
| EBP | 72 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 86.9 dB calc. |
Mounting dimensions
| Cutout diameter | 11 1/8″ |
|---|---|
| Mounting depth | 8 3/16″ |
Cone area (Sd) calculated from Fs, Vas and Mms: 72.1 in².
Judging by its value, the published Re is for both coils in series — converted to per coil.
“≈” 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
Other VM Audio 12″ models
- VM Audio EXW12 12″ · dual 4 Ω
- VM Audio SRW12 12″ · dual 4 Ω
Similar 12″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Machete MF-12R D4 0.71 ft³ sealed · 1.20 ft³ ported
- Avatar SST-312 D2 0.71 ft³ sealed · 1.20 ft³ ported
- Sundown Audio Ev4-12 D4 0.71 ft³ sealed · 1.77 ft³ ported
- DC Audio Level 4 M3 12 D1 0.64 ft³ sealed · 1.02 ft³ ported
- DC Audio Level 4 M3 12 D2 0.64 ft³ sealed · 1.02 ft³ ported
- DC Audio Level 4 M3 12 D4 0.64 ft³ sealed · 1.02 ft³ ported
FAQ
What box does the VM Audio ECW120 need?
Recommended net volume: 0.76 ft³ sealed, 1.17 ft³ ported tuned to 35 Hz — for one sub in a sedan at 1,500 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the VM Audio ECW120 Thiele/Small specs?
Fs 38 Hz, Qts 0.47, Vas 1.05 ft³, Sd 72.1 in².
What is the VM Audio ECW120 mounting depth?
Mounting depth is 8 3/16″, cutout diameter 11 1/8″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the VM Audio ECW120 handle and how do I wire it?
RMS power rating: 1,500 W. Dual 4 Ω voice coils: series gives 8 Ω, parallel gives 2 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.