Fi Audio Alpha v2 12 S4

12″ subwoofer · 4 Ω · 750 W RMS

Fs 40.7 HzQts 0.50Vas 0.98 ft³Xmax 0.63″

Recommended box

For a sedan, one sub, 750 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 volume0.67 ft³ (19 L)
Qtc0.79
Fc64 Hz
F3 (−3 dB, no cabin gain)61 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 9 11/16″
Open sealed box in designer

Ported

Net volume2.05 ft³ (58 L)
Tuning (Fb)35 Hz
Portslot 2 9/16 × 14 5/16″, 34 1/16″ long
Port velocity at 750 W61 ft/s
F3 (−3 dB, no cabin gain)32 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 13 5/8″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs40.7 Hz
Qts0.50
Qes0.55
Qms6.05
Vas0.98 ft³
Re3.1 Ω
Sd74.6 in²
Xmax0.63″
Vd47 in³ calc.
Mms180 g calc.
BL16.1 T·m calc.
EBP74 — sealed or ported calc.
Sensitivity, 1 W / 1 m87.3 dB calc.

General

Size12″
Voice coils4 Ω
RMS power750 W

Mounting dimensions

Ø12 1/2″cutout Ø11 1/8″mounting depth 6 3/4″magnet Ø≈ 7 1/4″
Cutout diameter11 1/8″
Mounting depth6 3/4″
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