Fi Audio SSD NEO 12 D2

12″ subwoofer · dual 2 Ω · 1,500 W RMS

39.1 HzFs, resonance

0.43Qts

0.86 ft³Vas

1.10″Xmax

1,500 WRMS

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, 1,500 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

0.71 ft³ (20 L)

Net volume

Bass character (Qtc)	Flat and accurate · 0.64
Fc	58 Hz
F3 (−3 dB, no cabin gain)	68 Hz
Example box (outside)	14 3/16″ × 14 3/16″ × 10 1/16″

Open sealed box in designer

Ported

deeper, louder

1.20 ft³ (34 L)

Net volume

Tuning (Fb)	34 Hz
Port	slot 1 9/16 × 14 5/16″, 39 9/16″ long
Port velocity at 1,500 W	101 ft/s
F3 (−3 dB, no cabin gain)	34 Hz
Example box (outside)	19 5/8″ × 15 3/4″ × 14 3/4″

At 1,500 W this example’s port will be noisy: air speed 101 ft/s, while the limit is 82 ft/s. It stays quiet up to about 980 W. Full power needs a port of at least 27.9 in², which means a bigger box than this example — size it in the designer.

Open ported box in designer

Deeper: 1.41 ft³ (40 L) tuned to 35 Hz, 24″ × 15 3/4″ × 14 3/4″ 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 2 Ω
RMS power	1,500 W
Fs	39.1 Hz
Qts	0.43
Qes	0.46
Qms	6.21
Vas	0.86 ft³

Re (one coil)	1.4 Ω
Sd	74.4 in²
Xmax	1.10″
Vd	82 in³ calc.
Mms	222 g calc.
BL	12.9 T·m calc.
EBP	85 — sealed or ported calc.
Sensitivity, 1 W / 1 m	87 dB calc.

Mounting dimensions

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

“≈” 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

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.

Gladen SPL 12 (DVC) 0.83 ft³ sealed · 2.26 ft³ ported
American Bass XFL-1244 0.83 ft³ sealed · 2.26 ft³ ported
Ground Zero GZNW 12XSPL (2x1 Ohm) 0.83 ft³ sealed · 1.24 ft³ ported
Sundown Audio SAv2-12 D2 0.74 ft³ sealed · 1.77 ft³ ported
DC Audio XL-SPL 12 D1 0.85 ft³ sealed · 2.26 ft³ ported
DC Audio XL-SPL 12 D2 0.85 ft³ sealed · 2.26 ft³ ported

FAQ

What box does the Fi Audio SSD NEO 12 D2 need?

Recommended net volume: 0.71 ft³ sealed, 1.20 ft³ ported tuned to 34 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 SSD NEO 12 D2 Thiele/Small specs?

Fs 39.1 Hz, Qts 0.43, Vas 0.86 ft³, Xmax 1.10″, Sd 74.4 in².

What is the Fi Audio SSD NEO 12 D2 mounting depth?

Mounting depth is 7 1/2″, 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 Fi Audio SSD NEO 12 D2 handle and how do I wire it?

RMS power rating: 1,500 W. Dual 2 Ω voice coils: series gives 4 Ω, parallel gives 1 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.