Quantum Audio QW5000/15D4
15″ subwoofer · dual 4 Ω
The Quantum Audio QW5000/15D4 is a 15″ subwoofer. With Qts 0.66 and EBP 40 it suits a sealed box: tight bass in a small enclosure; a ported box would need a lot of volume.
| 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) | Tight and punchy · 0.82 |
|---|---|
| Fc | 47 Hz |
| F3 (−3 dB, no cabin gain) | 43 Hz |
| Example box (outside) | 31 1/2″ × 17 11/16″ × 12 3/8″ |
Ported
deeper, louder| Tuning (Fb) | 34 Hz |
|---|---|
| Port | slot 1 9/16 × 16 5/16″, 24 13/16″ long |
| Port velocity at 300 W | 41 ft/s |
| F3 (−3 dB, no cabin gain) | 32 Hz |
| Example box (outside) | 22 7/16″ × 17 11/16″ × 15 3/16″ |
Deeper: 4.98 ft³ (141 L) tuned to 29 Hz, 31 1/2″ × 17 11/16″ × 20 11/16″ 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 | 37.8 Hz |
| Qts | 0.66 |
| Qes | 0.946 |
| Qms | 2.21 |
| Vas | 1.55 ft³ |
| Re (one coil) | 3.4 Ω |
|---|---|
| Sd | 128.7 in² |
| Xmax | 0.60″ |
| Vd | 77 in³ calc. |
| Mms | 395 g calc. |
| BL | 18.4 T·m calc. |
| EBP | 40 — suits sealed calc. |
| Sensitivity, 1 W / 1 m | 86 dB calc. |
Mounting dimensions
| Cutout diameter | 13 5/8″ |
|---|---|
| Mounting depth | 8″ |
| Overall diameter | 15 3/8″ |
Where it fits in a vehicle
Spots from our vehicle guides where the cutout, mounting depth and recommended box fit. The spot sizes are approximate — measure your own vehicle.
- Excursion — behind the third row sealed and ported box
Cone area (Sd) calculated from Fs, Vas and Mms: 128.7 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 Quantum Audio 15″ models
- Quantum Audio Q2000/15D 15″ · dual 4 Ω
- Quantum Audio Q2500/15D 15″ · dual 4 Ω
- Quantum Audio Q3000/15D 15″ · dual 4 Ω
- Quantum Audio QW3000/15D4 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.
- American Bass HD-1522 2.75 ft³ sealed · 3.25 ft³ ported
- Sundown Audio SAv2-15 D4 2.40 ft³ sealed · 3.00 ft³ ported
- Kicker Solo-Baric L7X 15" 2-Ohm DVC (49L7X152) 2.61 ft³ sealed · 5.01 ft³ ported
- DD Audio 9515k ESP D1 2.83 ft³ sealed · 1.98 ft³ ported
- DD Audio 9515k ESP D2 2.83 ft³ sealed · 1.98 ft³ ported
- DD Audio 9515L ESP D1 2.83 ft³ sealed · 1.98 ft³ ported
FAQ
What box does the Quantum Audio QW5000/15D4 need?
Recommended net volume: 2.93 ft³ sealed, 2.05 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 QW5000/15D4 Thiele/Small specs?
Fs 37.8 Hz, Qts 0.66, Vas 1.55 ft³, Xmax 0.60″, Sd 128.7 in².
What is the Quantum Audio QW5000/15D4 mounting depth?
Mounting depth is 8″, cutout diameter 13 5/8″. The inside depth of the box must exceed the mounting depth by at least 1″.
Is the Quantum Audio QW5000/15D4 better sealed or ported?
EBP 40: a sealed box (2.93 ft³) suits it best — tight bass in a compact enclosure. Ported is possible (2.05 ft³, tuned to 34 Hz) but larger.
What port does the Quantum Audio QW5000/15D4 need?
For the 2.05 ft³ ported box tuned to 34 Hz: slot 1 9/16 × 16 5/16″, 24 13/16″ long, area 25.7 in²; or a round port Ø5 11/16″, ≈ 24 13/16″ long. Port air speed at 300 W: 41 ft/s.
What box do two Quantum Audio QW5000/15D4 subs need?
Two subs need twice the volume: 5.86 ft³ sealed, or 4.10 ft³ ported at the same 34 Hz tuning with twice the port area. One shared chamber or one per sub — whatever fits your vehicle.