Quantum Audio QFW12D4
12″ subwoofer · dual 4 Ω
| Source | web.archive.org · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | not in the spec sheet: Xmax — 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, 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 · 0.83 |
|---|---|
| Fc | 54 Hz |
| F3 (−3 dB, no cabin gain) | 50 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 9 1/16″ |
Ported
deeper, louder| Tuning (Fb) | 34 Hz |
|---|---|
| Port | slot 1 9/16 × 14 5/16″, 33″ long |
| Port velocity at 300 W | 38 ft/s |
| F3 (−3 dB, no cabin gain) | 40 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 9 7/8″ |
Deeper: 3.04 ft³ (86 L) tuned to 36 Hz, 31 1/2″ × 15 3/4″ × 15″ 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 | 12″ |
|---|---|
| Voice coils | dual 4 Ω |
| RMS power | — |
| Fs | 38.7 Hz |
| Qts | 0.59 |
| Qes | 0.65 |
| Qms | 6.06 |
| Vas | 1.76 ft³ |
| Re (one coil) | 3.2 Ω |
|---|---|
| Sd | 78.7 in² |
| Xmax | ≈ 0.39″ |
| Mms | 124 g calc. |
| BL | 12.2 T·m calc. |
| EBP | 60 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 88.5 dB calc. |
Mounting dimensions
| Cutout diameter | 11 3/16″ |
|---|---|
| Mounting depth | 4 9/16″ |
| Overall diameter | 12 1/2″ |
Cone area (Sd) calculated from Fs, Vas and Mms: 78.7 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 12″ models
- Quantum Audio Q800/12D 12″ · dual 4 Ω
- Quantum Audio Q800/12S 12″ · 4 Ω
- Quantum Audio Q2000/12D 12″ · dual 4 Ω
- Quantum Audio Q2500/12D 12″ · dual 4 Ω
- Quantum Audio Q3000/12D 12″ · dual 4 Ω
- Quantum Audio QPW3000/12D4 12″ · dual 4 Ω
- Quantum Audio QSW12F 12″ · 4 Ω
- Quantum Audio QW1000/12D4 12″ · dual 4 Ω
- Quantum Audio QW1000/12S4 12″ · 4 Ω
- Quantum Audio QW3000/12D4 12″ · dual 4 Ω
- Quantum Audio QW5000/12D4 12″ · dual 4 Ω
- Quantum Audio QWX2000/12D4 12″ · dual 4 Ω
Similar 12″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Prology PS-12 Poseidon 1.73 ft³ sealed · 1.55 ft³ ported
- Hifonics ZXE12S4 1.80 ft³ sealed · 1.52 ft³ ported
- Rockville W12K5S4 1.73 ft³ sealed · 1.66 ft³ ported
- Skar Audio VD-12 D4 1.73 ft³ sealed · 1.77 ft³ ported
- Hertz Energy ES F30.5 (free-air/shallow, SVC 4 ohm) 1.84 ft³ sealed · 1.70 ft³ ported
- Bomber Outdoor 1200W 4 Ohm (SW12OUT-1200-4) 1.80 ft³ sealed · 1.55 ft³ ported
FAQ
What box does the Quantum Audio QFW12D4 need?
Recommended net volume: 1.80 ft³ sealed, 1.41 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 QFW12D4 Thiele/Small specs?
Fs 38.7 Hz, Qts 0.59, Vas 1.76 ft³, Sd 78.7 in².
What is the Quantum Audio QFW12D4 mounting depth?
Mounting depth is 4 9/16″, cutout diameter 11 3/16″. The inside depth of the box must exceed the mounting depth by at least 1″.