Sundown Audio SDv3-8 D2
8″ subwoofer · dual 2 Ω · 300 W RMS
| Source | web.archive.org · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | complete |
| Mounting dimensions | 3 of 4 — missing: magnet diameter; the designer will use an estimate |
Recommended box
For a sedan, one sub, 300 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 · 0.77 |
|---|---|
| Fc | 68 Hz |
| F3 (−3 dB, no cabin gain) | 66 Hz |
| Example box (outside) | 10 5/8″ × 10 5/8″ × 7 3/16″ |
Ported
deeper, louder| Tuning (Fb) | 42 Hz |
|---|---|
| Port | slot 1 15/16 × 14 5/16″, 88 3/4″ long |
| Port velocity at 300 W | 24 ft/s |
| F3 (−3 dB, no cabin gain) | 38 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 10 1/16″ |
The volume and tuning are the recommendation, but the port doesn’t fit this example box. Size the box and port in the designer.
Open ported box in designerDeeper: 0.64 ft³ (18 L) tuned to 46 Hz, 16 5/16″ × 15 3/4″ × 7 5/16″ 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 | 8″ |
|---|---|
| Voice coils | dual 2 Ω |
| RMS power | 300 W |
| Fs | 49.1 Hz |
| Qts | 0.55 |
| Qes | 0.63 |
| Qms | 4.39 |
| Vas | 0.23 ft³ |
| Re (one coil) | 2 Ω |
|---|---|
| Sd | 29 in² |
| Xmax | 0.57″ |
| Vd | 16.6 in³ calc. |
| Mms | 79 g calc. |
| BL | 8.8 T·m calc. |
| EBP | 78 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 82.9 dB calc. |
Mounting dimensions
| Cutout diameter | 7 3/8″ |
|---|---|
| Mounting depth | 4 3/4″ |
| Overall diameter | 8 3/8″ |
Cone area (Sd) calculated from Fs, Vas and Mms: 29 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
Other Sundown Audio 8″ models
- Sundown Audio Ev5-8 D2 8″ · dual 2 Ω
- Sundown Audio Ev5-8 D4 8″ · dual 4 Ω
- Sundown Audio Ev6-8 D2 8″ · dual 2 Ω
- Sundown Audio Ev6-8 D4 8″ · dual 4 Ω
- Sundown Audio HZ-8 D4 8″ · dual 4 Ω
- Sundown Audio M8 D2 8″ · dual 2 Ω
- Sundown Audio M8 D4 8″ · dual 4 Ω
- Sundown Audio SAv3-8 D2 8″ · dual 2 Ω
- Sundown Audio SAv3-8 D4 8″ · dual 4 Ω
- Sundown Audio SDv3-8 D4 8″ · dual 4 Ω
- Sundown Audio SDv4-8 D2 8″ · dual 2 Ω
- Sundown Audio SDv4-8 D4 8″ · dual 4 Ω
Similar 8″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Diamond CM308D4 0.28 ft³ sealed · 0.49 ft³ ported
- Phoenix Gold ZXT8D2 (slim, DVC 2 ohm) 0.35 ft³ sealed · 0.53 ft³ ported
- Memphis Car Audio MJM822 (MOJO Mini 8" DVC 2ohm) 0.30 ft³ sealed · 0.53 ft³ ported
- American Bass XD-844 0.32 ft³ sealed · 0.49 ft³ ported
- Alpine S2-W8D2 0.28 ft³ sealed · 0.60 ft³ ported
- Skar Audio SVR-8 D4 0.28 ft³ sealed · 0.67 ft³ ported
FAQ
What box does the Sundown Audio SDv3-8 D2 need?
Recommended net volume: 0.25 ft³ sealed, 0.46 ft³ ported tuned to 42 Hz — for one sub in a sedan at 300 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Sundown Audio SDv3-8 D2 Thiele/Small specs?
Fs 49.1 Hz, Qts 0.55, Vas 0.23 ft³, Xmax 0.57″, Sd 29 in².
What is the Sundown Audio SDv3-8 D2 mounting depth?
Mounting depth is 4 3/4″, cutout diameter 7 3/8″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Sundown Audio SDv3-8 D2 handle and how do I wire it?
RMS power rating: 300 W. Dual 2 Ω voice coils: series gives 4 Ω, parallel gives 1 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.