Quantum Audio Q2500/15D
15″ subwoofer · dual 4 Ω
| 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) | Boomy, with a bump · 1.31 |
|---|---|
| Fc | 50 Hz |
| F3 (−3 dB, no cabin gain) | 37 Hz |
| Example box (outside) | 31 1/2″ × 17 11/16″ × 12″ |
Ported
deeper, louder| Tuning (Fb) | 34 Hz |
|---|---|
| Port | slot 1 9/16 × 16 5/16″, 16 9/16″ long |
| Port velocity at 300 W | 42 ft/s |
| F3 (−3 dB, no cabin gain) | 34 Hz |
| Example box (outside) | 31 1/2″ × 17 11/16″ × 13 1/4″ |
Deeper: 4.80 ft³ (136 L) tuned to 38 Hz, 31 1/2″ × 17 11/16″ × 19 7/16″ 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 | 15″ |
|---|---|
| Voice coils | dual 4 Ω |
| RMS power | — |
| Fs | 33.3 Hz |
| Qts | 0.87 |
| Qes | 0.99 |
| Qms | 7.03 |
| Vas | 3.58 ft³ |
| Re (one coil) | 3.2 Ω |
|---|---|
| Sd | 124 in² |
| Xmax | 0.50″ |
| Vd | 62 in³ calc. |
| Mms | 205 g calc. |
| BL | 11.8 T·m calc. |
| EBP | 34 — suits sealed calc. |
| Sensitivity, 1 W / 1 m | 87.8 dB calc. |
Mounting dimensions
| Cutout diameter | 13 13/16″ |
|---|---|
| Mounting depth | 7 3/8″ |
| Overall diameter | 15 3/8″ |
Cone area (Sd) calculated from Fs, Vas and Mms: 124.1 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/20150906194829/http://www.quantumaudio.net/wp-content/upload
- web.archive.org/web/20130218223932/http://www.quantumaudio.net/q2500_12d.html
Other Quantum Audio 15″ models
- Quantum Audio Q2000/15D 15″ · dual 4 Ω
- Quantum Audio Q3000/15D 15″ · dual 4 Ω
- Quantum Audio QW3000/15D4 15″ · dual 4 Ω
- Quantum Audio QW5000/15D4 15″ · dual 4 Ω
- Quantum Audio QWX4000/15D4 15″ · dual 4 Ω
Similar 15″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Hertz Energy ES 380.5 (SVC 4 ohm) 2.86 ft³ sealed · 2.79 ft³ ported
- VM Audio EXW15 2.68 ft³ sealed · 2.79 ft³ ported
- Audiobahn AW151T 2.75 ft³ sealed · 2.12 ft³ ported
- Audiobahn AW152N 2.75 ft³ sealed · 2.08 ft³ ported
- Audiobahn AW152T 2.75 ft³ sealed · 2.08 ft³ ported
- Machete MS-15 D4 2.83 ft³ sealed · 3.00 ft³ ported
FAQ
What box does the Quantum Audio Q2500/15D need?
Recommended net volume: 2.83 ft³ sealed, 2.86 ft³ ported tuned to 34 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 Quantum Audio Q2500/15D Thiele/Small specs?
Fs 33.3 Hz, Qts 0.87, Vas 3.58 ft³, Xmax 0.50″, Sd 124 in².
What is the Quantum Audio Q2500/15D mounting depth?
Mounting depth is 7 3/8″, cutout diameter 13 13/16″. The inside depth of the box must exceed the mounting depth by at least 1″.