Sundown Audio Xv2-15 D4

15″ subwoofer · dual 4 Ω · 1,500 W RMS

29.5 HzFs, resonance

0.45Qts

2.10 ft³Vas

1.18″Xmax

1,500 WRMS

Source	web.archive.org · manufacturer data
Checked against source	October 2026
Thiele/Small parameters	complete
Mounting dimensions	2 of 4 — missing: frame outer diameter, magnet diameter; the designer will use an estimate

Recommended box

For a sedan, one sub, 1,500 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

1.48 ft³ (42 L)

Net volume

Bass character (Qtc)	Flat and accurate · 0.71
Fc	46 Hz
F3 (−3 dB, no cabin gain)	48 Hz
Example box (outside)	16 15/16″ × 16 15/16″ × 13 5/16″

Open sealed box in designer

Ported

deeper, louder

1.80 ft³ (51 L)

Net volume

Tuning (Fb)	32 Hz
Port	slot 2 3/16 × 16 5/16″, 46 1/4″ long
Port velocity at 1,500 W	67 ft/s
F3 (−3 dB, no cabin gain)	31 Hz
Example box (outside)	31 1/2″ × 17 11/16″ × 12 5/8″

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 designer

Deeper: 3.25 ft³ (92 L) tuned to 28 Hz, 31 1/2″ × 17 11/16″ × 20 1/8″ outside — a bigger box with flatter deep bass. Open in the calculator

Where to buy Amazon

Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Size	15″
Voice coils	dual 4 Ω
RMS power	1,500 W
Fs	29.5 Hz
Qts	0.45
Qes	0.5
Qms	4.92
Vas	2.10 ft³

Re (one coil)	3.05 Ω
Sd	112.5 in²
Xmax	1.18″
Vd	132.9 in³ calc.
Mms	365 g calc.
BL	20.3 T·m calc.
EBP	59 — sealed or ported calc.
Sensitivity, 1 W / 1 m	86.9 dB calc.

Mounting dimensions

Cutout diameter	13 13/16″
Mounting depth	10 7/8″

Cone area (Sd) calculated from Fs, Vas and Mms: 112.5 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/20161216050348/http://www.sundownaudio.com/index.php/subwoof

Other Sundown Audio 15″ models

Sundown Audio Ev2-15 D2 15″ · dual 2 Ω
Sundown Audio Ev2-15 D4 15″ · dual 4 Ω
Sundown Audio Ev4-15 D2 15″ · dual 2 Ω
Sundown Audio Ev4-15 D4 15″ · dual 4 Ω
Sundown Audio M15 D1 15″ · dual 1 Ω
Sundown Audio M15 D2 15″ · dual 2 Ω
Sundown Audio NSv1-15 D2 15″ · dual 2 Ω
Sundown Audio NSv2-15 D2 15″ · dual 2 Ω
Sundown Audio NSv4-15 D1 15″ · dual 1 Ω
Sundown Audio NSv4-15 D2 15″ · dual 2 Ω
Sundown Audio NSv6-15 D1 15″ · dual 1 Ω
Sundown Audio NSv6-15 D2 15″ · dual 2 Ω

Similar 15″ subwoofers from other brands

Close in Fs, Qts and Vas — a box of similar volume will suit them.

Deaf Bonce Apocalypse DB-4.5K 15" D1 1.13 ft³ sealed · 1.98 ft³ ported
Deaf Bonce Apocalypse DB-375 D1 1.82 ft³ sealed · 1.98 ft³ ported
Fi Audio NEO 4.7 15 D1 1.59 ft³ sealed · 2.01 ft³ ported
Fi Audio NEO 4.7 15 D2 1.59 ft³ sealed · 2.01 ft³ ported
Deaf Bonce Apocalypse DB-4.5K 15" D2 1.13 ft³ sealed · 1.98 ft³ ported
Deaf Bonce Apocalypse DB-375 D2 1.82 ft³ sealed · 1.98 ft³ ported

FAQ

What box does the Sundown Audio Xv2-15 D4 need?

Recommended net volume: 1.48 ft³ sealed, 1.80 ft³ ported tuned to 32 Hz — for one sub in a sedan at 1,500 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.

What are the Sundown Audio Xv2-15 D4 Thiele/Small specs?

Fs 29.5 Hz, Qts 0.45, Vas 2.10 ft³, Xmax 1.18″, Sd 112.5 in².

What is the Sundown Audio Xv2-15 D4 mounting depth?

Mounting depth is 10 7/8″, cutout diameter 13 13/16″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Sundown Audio Xv2-15 D4 handle and how do I wire it?

RMS power rating: 1,500 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.