Diamond M3080
8″ subwoofer · 4 Ω · 125 W RMS
| Source | web.archive.org · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | not in the spec sheet: Re — typical value for the size used |
| Mounting dimensions | 3 of 4 — missing: magnet diameter; the designer will use an estimate |
Recommended box
For a sedan, one sub, 125 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) | Tight and punchy · 0.79 |
|---|---|
| Fc | 67 Hz |
| F3 (−3 dB, no cabin gain) | 65 Hz |
| Example box (outside) | 10 1/4″ × 10 1/4″ × 9 1/4″ |
Ported
deeper, louder| Tuning (Fb) | 43 Hz |
|---|---|
| Port | 2 round ports Ø2 1/2″, 18 9/16″ long |
| Port velocity at 125 W | 54 ft/s |
| F3 (−3 dB, no cabin gain) | 40 Hz |
| Example box (outside) | 22 1/2″ × 15 3/4″ × 6 1/2″ |
Deeper: 1.02 ft³ (29 L) tuned to 36 Hz, 31 1/2″ × 15 3/4″ × 8″ 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 | 4 Ω |
| RMS power | 125 W |
| Fs | 35 Hz |
| Qts | 0.41 |
| Qes | 0.44 |
| Qms | 6.3 |
| Vas | 0.86 ft³ |
| Re | ≈ 3.4 Ω |
|---|---|
| Sd | 32.6 in² |
| Xmax | 0.31″ |
| Vd | 10.3 in³ calc. |
| Mms | 53 g calc. |
| BL | 9.5 T·m calc. |
| EBP | 80 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 85.8 dB calc. |
Mounting dimensions
| Cutout diameter | 7 1/8″ |
|---|---|
| Mounting depth | 4″ |
| Overall diameter | 8 3/8″ |
“≈” 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 Diamond 8″ models
- Diamond CM308D2 8″ · dual 2 Ω
- Diamond CM308D4 8″ · dual 4 Ω
Similar 8″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- STX W.20.300.2x4.MC 0.35 ft³ sealed · 0.71 ft³ ported
- ESX SX840 (4 Ohm) 0.32 ft³ sealed · 0.99 ft³ ported
- Orion Cobalt 8 DVC (original) 0.28 ft³ sealed · 0.92 ft³ ported
- STX W.20.300.2x2.MC 0.32 ft³ sealed · 0.74 ft³ ported
- Orion XTR 8 SVC (original) 0.28 ft³ sealed · 0.92 ft³ ported
- ESX SXE8D2 (2x2 Ohm) 0.32 ft³ sealed · 0.99 ft³ ported
FAQ
What box does the Diamond M3080 need?
Recommended net volume: 0.32 ft³ sealed, 0.71 ft³ ported tuned to 43 Hz — for one sub in a sedan at 125 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Diamond M3080 Thiele/Small specs?
Fs 35 Hz, Qts 0.41, Vas 0.86 ft³, Xmax 0.31″, Sd 32.6 in².
What is the Diamond M3080 mounting depth?
Mounting depth is 4″, cutout diameter 7 1/8″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Diamond M3080 handle and how do I wire it?
RMS power rating: 125 W. Wiring for several subs and amp power — in the wiring calculator.