Sundown Audio Xv1-12 D4
12″ subwoofer · dual 4 Ω · 1,250 W RMS
The Sundown Audio Xv1-12 D4 is a 12″ subwoofer. With Qts 0.48 and EBP 50 it works both sealed and ported: sealed is tighter and smaller, ported is deeper and louder. Long excursion (Xmax 1.18″) — built for loud music and high power.
| 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, 1,250 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) | Flat and accurate · 0.70 |
|---|---|
| Fc | 39 Hz |
| F3 (−3 dB, no cabin gain) | 41 Hz |
| Example box (outside) | 14 3/16″ × 14 3/16″ × 12 1/8″ |
Ported
deeper, louder| Tuning (Fb) | 30 Hz |
|---|---|
| Port | slot 1 15/16 × 14 5/16″, 67 1/2″ long |
| Port velocity at 1,250 W | 65 ft/s |
| F3 (−3 dB, no cabin gain) | 27 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 11 7/8″ |
The volume and tuning are the recommendation, but the port doesn’t fit this example box. Size the box and port in the designer.
Open ported box in designerDeeper: 1.84 ft³ (52 L) tuned to 25 Hz, 23 3/8″ × 15 3/4″ × 16 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 | 1,250 W |
| Fs | 26.5 Hz |
| Qts | 0.48 |
| Qes | 0.53 |
| Qms | 5.15 |
| Vas | 1.01 ft³ |
| Re (one coil) | 3.05 Ω |
|---|---|
| Sd | 72.7 in² |
| Xmax | 1.18″ |
| Vd | 85.9 in³ calc. |
| Mms | 393 g calc. |
| BL | 19.4 T·m calc. |
| EBP | 50 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 82 dB calc. |
Mounting dimensions
| Cutout diameter | 11 1/8″ |
|---|---|
| Mounting depth | 9 11/16″ |
| Overall diameter | 12 11/16″ |
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
- 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
Cone area (Sd) calculated from Fs, Vas and Mms: 72.7 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
- web.archive.org/web/20190807034628/http://sundownaudio.com/index.php/products/di
- web.archive.org/web/20210125011608/https://sundownaudio.com/lv/sa/discontinued/d
Voice coil versions
The same sub with different voice coils: the parameters are nearly the same — pick by your amp and wiring.
| Model | Voice coils | Re | Qes | Vas | Sealed | Ported |
|---|---|---|---|---|---|---|
| Sundown Audio Xv1-12 D2 | dual 2 Ω | 1.9 Ω | 0.45 | 1.11 ft³ | 0.90 ft³ | 1.17 ft³ · 30 Hz |
| Sundown Audio Xv1-12 D4 | dual 4 Ω | 3.05 Ω | 0.53 | 1.01 ft³ | 0.90 ft³ | 1.17 ft³ · 30 Hz |
Other Sundown Audio 12″ models
- Sundown Audio Ev2-12 D2 12″ · dual 2 Ω
- Sundown Audio Ev2-12 D4 12″ · dual 4 Ω
- Sundown Audio Ev4-12 D2 12″ · dual 2 Ω
- Sundown Audio Ev4-12 D4 12″ · dual 4 Ω
- Sundown Audio HZ-12 D4 12″ · dual 4 Ω
- Sundown Audio HZS-12 D4 12″ · dual 4 Ω
- Sundown Audio LCSv1-12 D4 12″ · dual 4 Ω
- Sundown Audio LCSv2-12 D4 12″ · dual 4 Ω
- Sundown Audio M12 D1 12″ · dual 1 Ω
- Sundown Audio M12 D2 12″ · dual 2 Ω
- Sundown Audio NSv1-12 D2 12″ · dual 2 Ω
- Sundown Audio NSv2-12 D2 12″ · dual 2 Ω
Similar 12″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Sky High Car Audio BMX-12 D1 0.74 ft³ sealed · 1.13 ft³ ported
- Cadence S2W12D4 0.74 ft³ sealed · 1.20 ft³ ported
- Ground Zero GZRW 30-D2 (2x2 Ohm) 0.71 ft³ sealed · 1.20 ft³ ported
- Sky High Car Audio BMX-12 D2 0.74 ft³ sealed · 1.13 ft³ ported
- Fi Audio SP4 12 D1 1.06 ft³ sealed · 1.20 ft³ ported
- Fi Audio SP412 v2.1 D1 0.94 ft³ sealed · 1.20 ft³ ported
FAQ
What box does the Sundown Audio Xv1-12 D4 need?
Recommended net volume: 0.90 ft³ sealed, 1.17 ft³ ported tuned to 30 Hz — for one sub in a sedan at 1,250 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Sundown Audio Xv1-12 D4 Thiele/Small specs?
Fs 26.5 Hz, Qts 0.48, Vas 1.01 ft³, Xmax 1.18″, Sd 72.7 in².
What is the Sundown Audio Xv1-12 D4 mounting depth?
Mounting depth is 9 11/16″, cutout diameter 11 1/8″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Sundown Audio Xv1-12 D4 handle and how do I wire it?
RMS power rating: 1,250 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 Sundown Audio Xv1-12 D4 better sealed or ported?
EBP 50: both work — sealed 0.90 ft³ is tighter and smaller, ported 1.17 ft³ tuned to 30 Hz is deeper and louder.
What port does the Sundown Audio Xv1-12 D4 need?
For the 1.17 ft³ ported box tuned to 30 Hz: slot 1 15/16 × 14 5/16″, 67 1/2″ long, area 28.2 in²; or a round port Ø6″, ≈ 67 1/2″ long. Port air speed at 1,250 W: 65 ft/s.
What box do two Sundown Audio Xv1-12 D4 subs need?
Two subs need twice the volume: 1.80 ft³ sealed, or 2.33 ft³ ported at the same 30 Hz tuning with twice the port area. One shared chamber or one per sub — whatever fits your vehicle.