Quantum Audio Q800/12S
12″ subwoofer · 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 · 1.36 |
|---|---|
| Fc | 56 Hz |
| F3 (−3 dB, no cabin gain) | 42 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 8 15/16″ |
Ported
deeper, louder| Tuning (Fb) | 34 Hz |
|---|---|
| Port | slot 1 9/16 × 14 5/16″, 28 3/16″ long |
| Port velocity at 300 W | 35 ft/s |
| F3 (−3 dB, no cabin gain) | 39 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 10 3/8″ |
Deeper: 3.00 ft³ (85 L) tuned to 42 Hz, 31 1/2″ × 15 3/4″ × 14 3/8″ 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 | 12″ |
|---|---|
| Voice coils | 4 Ω |
| RMS power | — |
| Fs | 38.4 Hz |
| Qts | 0.92 |
| Qes | 1.08 |
| Qms | 6.4 |
| Vas | 2.04 ft³ |
| Re | 3.2 Ω |
|---|---|
| Sd | 77.6 in² |
| Xmax | 0.40″ |
| Vd | 31.1 in³ calc. |
| Mms | 105 g calc. |
| BL | 8.7 T·m calc. |
| EBP | 36 — suits sealed calc. |
| Sensitivity, 1 W / 1 m | 86.8 dB calc. |
Mounting dimensions
| Cutout diameter | 10 7/8″ |
|---|---|
| Mounting depth | 5 1/2″ |
| Overall diameter | 12 1/16″ |
Cone area (Sd) calculated from Fs, Vas and Mms: 77.6 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/20150920002141/http://www.quantumaudio.net/wp-content/upload
- web.archive.org/web/20130726023000/http://www.quantumaudio.net/q800_12d.html
Other Quantum Audio 12″ models
- Quantum Audio Q800/12D 12″ · dual 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 QFW12D4 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.
- Massive Audio ECO12S4 1.80 ft³ sealed · 1.91 ft³ ported
- Hinor HSW12 Carbono 1.87 ft³ sealed · 1.41 ft³ ported
- Bomber Carbon 500W 4+4 Ohm (SW12CB-500-4+4) 1.84 ft³ sealed · 1.70 ft³ ported
- JBL MS-12SD4 1.80 ft³ sealed · 1.34 ft³ ported
- Bomber Slim High Power 400W 4 Ohm (SW12SLHP-400-4) 1.80 ft³ sealed · 1.48 ft³ ported
- Cerwin-Vega Mobile HS124D (HED Shallow 12" DVC 4ohm) 1.87 ft³ sealed · 1.45 ft³ ported
FAQ
What box does the Quantum Audio Q800/12S need?
Recommended net volume: 1.77 ft³ sealed, 1.62 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 Q800/12S Thiele/Small specs?
Fs 38.4 Hz, Qts 0.92, Vas 2.04 ft³, Xmax 0.40″, Sd 77.6 in².
What is the Quantum Audio Q800/12S mounting depth?
Mounting depth is 5 1/2″, cutout diameter 10 7/8″. The inside depth of the box must exceed the mounting depth by at least 1″.