Fi Audio SP4 12 D2

12″ subwoofer · dual 2 Ω · 3,000 W RMS

Fs 27.9 HzQts 0.44Vas 0.97 ft³Xmax 1.30″

Recommended box

For a sedan, one sub, 3,000 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

Net volume1.06 ft³ (30 L)
Qtc0.60
Fc39 Hz
F3 (−3 dB, no cabin gain)48 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 13 13/16″
Open sealed box in designer

Ported

Net volume1.41 ft³ (40 L)
Tuning (Fb)27 Hz
Portslot 1 15/16 × 14 5/16″, 68 13/16″ long
Port velocity at 3,000 W111 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 13″

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
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs27.9 Hz
Qts0.44
Qes0.47
Qms6.01
Vas0.97 ft³
Re (one coil)1.27 Ω
Sd74.4 in²
Xmax1.30″
Vd96.7 in³ calc.
Mms388 g calc.
BL13.5 T·m calc.
EBP59 — sealed or ported calc.
Sensitivity, 1 W / 1 m83 dB calc.

General

Size12″
Voice coilsdual 2 Ω
RMS power3,000 W

Mounting dimensions

Ø12 1/2″cutout Ø11 1/8″mounting depth 11 1/4″magnet Ø≈ 7 1/4″
Cutout diameter11 1/8″
Mounting depth11 1/4″
Overall diameter12 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