Avatar Doomsday 18 D1
18″ subwoofer · dual 1 Ω · 3,500 W RMS
Fs 29 HzQts 0.45Vas 2.70 ft³Xmax 0.79″
Recommended box
For a sedan, one sub, 3,500 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
| Net volume | 2.37 ft³ (67 L) |
|---|---|
| Qtc | 0.66 |
| Fc | 42 Hz |
| F3 (−3 dB, no cabin gain) | 48 Hz |
| Example box (outside) | 20 1/16″ × 20 1/16″ × 14 9/16″ |
Ported
| Net volume | 4.10 ft³ (116 L) |
|---|---|
| Tuning (Fb) | 28 Hz |
| Port | slot 4 5/16 × 19 7/16″, 62 1/2″ long |
| Port velocity at 3,500 W | 71 ft/s |
| F3 (−3 dB, no cabin gain) | 26 Hz |
| Example box (outside) | 31 1/2″ × 20 7/8″ × 24 1/2″ |
Thiele/Small parameters
| Fs | 29 Hz |
|---|---|
| Qts | 0.45 |
| Qes | 0.486 |
| Qms | 6 |
| Vas | 2.70 ft³ |
| Re (one coil) | ≈ 0.85 Ω |
| Sd | ≈ 180.6 in² |
| Xmax | 0.79″ |
| EBP | 60 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 87.8 dB calc. |
General
| Size | 18″ |
|---|---|
| Voice coils | dual 1 Ω |
| RMS power | 3,500 W |
Mounting dimensions
| Cutout diameter | 16 3/4″ |
|---|---|
| Mounting depth | 12 1/8″ |
Only Qts is published — Qms assumed to be 6 and Qes calculated (barely affects box design).
“≈” 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 Avatar 18″ models
- Avatar Doomsday 18 D2 18″ · dual 2 Ω