Fi Audio Xv5 12 D1

12″ subwoofer · dual 1 Ω · 1,500 W RMS

38.4 HzFs, resonance

0.57Qts

0.43 ft³Vas

0.91″Xmax

1,500 WRMS

Source	ficaraudio.com · 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

The published specs don’t add up:

Fs, Vas and Sd don't match the moving mass of 280.2 g (they give 416 g) — one of the spec sheet values is probably wrong.

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

0.67 ft³ (19 L)

Net volume

Bass character (Qtc)	Flat and accurate · 0.73
Fc	49 Hz
F3 (−3 dB, no cabin gain)	49 Hz
Example box (outside)	14 3/16″ × 14 3/16″ × 9 11/16″

Open sealed box in designer

Ported

deeper, louder

1.13 ft³ (32 L)

Net volume

Tuning (Fb)	35 Hz
Port	slot 1 9/16 × 14 5/16″, 39 5/8″ long
Port velocity at 1,500 W	104 ft/s
F3 (−3 dB, no cabin gain)	30 Hz
Example box (outside)	19 9/16″ × 15 3/4″ × 14 3/8″

At 1,500 W this example’s port will be noisy: air speed 104 ft/s, while the limit is 82 ft/s. It stays quiet up to about 930 W. Full power needs a port of at least 28.6 in², which means a bigger box than this example — size it in the designer.

Open ported box in designer

Deeper: 1.34 ft³ (38 L) tuned to 29 Hz, 25 1/8″ × 15 3/4″ × 9 5/8″ 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	12″
Voice coils	dual 1 Ω
RMS power	1,500 W
Fs	38.4 Hz
Qts	0.57
Qes	0.649
Qms	4.85
Vas	0.43 ft³

Re (one coil)	1 Ω
Sd	70.9 in²
Xmax	0.91″
Vd	64.2 in³ calc.
Mms	416 g calc.
BL	12.4 T·m calc.
EBP	59 — sealed or ported calc.
Sensitivity, 1 W / 1 m	82.3 dB calc.

Mounting dimensions

Cutout diameter	11″
Mounting depth	7 1/8″
Overall diameter	12 1/2″

Judging by its value, the published Re is for both coils in series — converted to per coil.

“≈” 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

ficaraudio.com/xv5-series-12-subwoofer/

Other Fi Audio 12″ models

Fi Audio Alpha 12 S2 12″ · 2 Ω
Fi Audio Alpha 12 S4 12″ · 4 Ω
Fi Audio Alpha v1 12 S1 12″ · 1 Ω
Fi Audio Alpha v1 12 S2 12″ · 2 Ω
Fi Audio Alpha v1 12 S4 12″ · 4 Ω
Fi Audio Alpha v2 12 S2 12″ · 2 Ω
Fi Audio Alpha v2 12 S4 12″ · 4 Ω
Fi Audio Alpha v2.1 12 S2 12″ · 2 Ω
Fi Audio Alpha v2.1 12 S4 12″ · 4 Ω
Fi Audio BL-NEO 12 D1 12″ · dual 1 Ω
Fi Audio BL-NEO 12 D2 12″ · dual 2 Ω
Fi Audio BL12 D1 12″ · dual 1 Ω

Similar 12″ subwoofers from other brands

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

Massive Audio BOA121 0.94 ft³ sealed · 1.13 ft³ ported
Rockford Fosgate Power T2D412 0.78 ft³ sealed · 1.80 ft³ ported
Hifonics ZXT12D2 0.81 ft³ sealed · 1.17 ft³ ported
Sundown Audio Xv3-12 D1 0.90 ft³ sealed · 2.51 ft³ ported
Sundown Audio Xv4-12 D1 1.09 ft³ sealed · 2.51 ft³ ported
Ground Zero GZNW 30XMAX-II (2x1 Ohm) 0.92 ft³ sealed · 1.20 ft³ ported

FAQ

What box does the Fi Audio Xv5 12 D1 need?

Recommended net volume: 0.67 ft³ sealed, 1.13 ft³ ported tuned to 35 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 Fi Audio Xv5 12 D1 Thiele/Small specs?

Fs 38.4 Hz, Qts 0.57, Vas 0.43 ft³, Xmax 0.91″, Sd 70.9 in².

What is the Fi Audio Xv5 12 D1 mounting depth?

Mounting depth is 7 1/8″, cutout diameter 11″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Fi Audio Xv5 12 D1 handle and how do I wire it?

RMS power rating: 1,500 W. Dual 1 Ω voice coils: series gives 2 Ω, parallel gives 0.5 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.