Quantum Audio QWX2000/12D4
12″ subwoofer · dual 4 Ω · 500 W RMS
The Quantum Audio QWX2000/12D4 is a 12″ subwoofer. With Qts 0.66 and EBP 46 it suits a sealed box: tight bass in a small enclosure; a ported box would need a lot of volume.
| Source | web.archive.org, dbdrive.net · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | complete |
| Mounting dimensions | 0 of 4 — missing: cutout, mounting depth, frame outer diameter, magnet diameter; the designer will use an estimate |
Recommended box
For a sedan, one sub, 500 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 · 0.90 |
|---|---|
| Fc | 48 Hz |
| F3 (−3 dB, no cabin gain) | 42 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″, 37 1/8″ long |
| Port velocity at 500 W | 45 ft/s |
| F3 (−3 dB, no cabin gain) | 36 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 9 5/8″ |
Deeper: 3.07 ft³ (87 L) tuned to 33 Hz, 31 1/2″ × 15 3/4″ × 15 15/16″ 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 | 12″ |
|---|---|
| Voice coils | dual 4 Ω |
| RMS power | 500 W |
| Fs | 35.6 Hz |
| Qts | 0.66 |
| Qes | 0.769 |
| Qms | 4.52 |
| Vas | 1.55 ft³ |
| Re (one coil) | 3.6 Ω |
|---|---|
| Sd | 79.2 in² |
| Xmax | 0.51″ |
| Vd | 40.5 in³ calc. |
| Mms | 169 g calc. |
| BL | 13.3 T·m calc. |
| EBP | 46 — suits sealed calc. |
| Sensitivity, 1 W / 1 m | 86.1 dB calc. |
Mounting dimensions
| Cutout diameter | ≈ 11 1/8″ |
|---|---|
| Mounting depth | ≈ 5 7/8″ |
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.
- Bronco 4-door — behind the rear seat sealed and ported box
- Wrangler 4-door, hard top — behind the rear seat sealed and ported box
- Wrangler 4-door, soft top — behind the rear seat sealed and ported box
- Silverado / Sierra Crew Cab — under the rear seat sealed and ported box
- FJ Cruiser — behind the rear seat sealed and ported box
- El Camino 1978–87 — behind the seat sealed and ported box
- Cherokee XJ — cargo area, spare moved out sealed and ported box
- Excursion — behind the third row sealed and ported box
- Mustang 2015–2023 coupe — trunk sealed and ported box
- Challenger / Charger — trunk sealed and ported box
- Club Car Precedent — under the rear seat sealed and ported box
“≈” 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/20240624040747/https://quantumaudio.net/wp-content/uploads/2
- web.archive.org/web/20240613053229/https://quantumaudio.net/wp-content/uploads/2
- dbdrive.net/products/qwx2000-12d4-12in-ohm-dvc-quantum-x-series-woofer
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 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
Similar 12″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Kicker CompVT 12" 2-Ohm SVC (43CVT122) 1.87 ft³ sealed · 1.31 ft³ ported
- Hertz Energy ES 300.5 (SVC 4 ohm) 1.80 ft³ sealed · 1.38 ft³ ported
- Kicker CompVT 12" 4-Ohm SVC (43CVT124) 1.87 ft³ sealed · 1.38 ft³ ported
- Sky High Car Audio FEX-12 D4 1.80 ft³ sealed · 1.27 ft³ ported
- Sky High Car Audio FEX-12 D2 1.80 ft³ sealed · 1.27 ft³ ported
- MTX Audio 5512-22 1.98 ft³ sealed · 1.80 ft³ ported
FAQ
What box does the Quantum Audio QWX2000/12D4 need?
Recommended net volume: 1.80 ft³ sealed, 1.27 ft³ ported tuned to 34 Hz — for one sub in a sedan at 500 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Quantum Audio QWX2000/12D4 Thiele/Small specs?
Fs 35.6 Hz, Qts 0.66, Vas 1.55 ft³, Xmax 0.51″, Sd 79.2 in².
How much power does the Quantum Audio QWX2000/12D4 handle and how do I wire it?
RMS power rating: 500 W. Dual 4 Ω voice coils: series gives 8 Ω, parallel gives 2 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.
Is the Quantum Audio QWX2000/12D4 better sealed or ported?
EBP 46: a sealed box (1.80 ft³) suits it best — tight bass in a compact enclosure. Ported is possible (1.27 ft³, tuned to 34 Hz) but larger.
What port does the Quantum Audio QWX2000/12D4 need?
For the 1.27 ft³ ported box tuned to 34 Hz: slot 1 9/16 × 14 5/16″, 37 1/8″ long, area 22.6 in²; or a round port Ø5 3/8″, ≈ 37 1/8″ long. Port air speed at 500 W: 45 ft/s.
What box do two Quantum Audio QWX2000/12D4 subs need?
Two subs need twice the volume: 3.60 ft³ sealed, or 2.54 ft³ ported at the same 34 Hz tuning with twice the port area. One shared chamber or one per sub — whatever fits your vehicle.