Fi Audio Alpha v2.1 12 S2

12″ subwoofer · 2 Ω · 750 W RMS

Fs 37.5 HzQts 0.54Vas 1.03 ft³Xmax 0.67″

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 volume0.85 ft³ (24 L)
Qtc0.80
Fc56 Hz
F3 (−3 dB, no cabin gain)53 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 11 9/16″
Open sealed box in designer

Ported

Net volume2.61 ft³ (74 L)
Tuning (Fb)31 Hz
Portslot 2 3/4 × 14 5/16″, 36 7/8″ long
Port velocity at 750 W61 ft/s
F3 (−3 dB, no cabin gain)27 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 16 3/8″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs37.5 Hz
Qts0.54
Qes0.58
Qms7.44
Vas1.03 ft³
Re1.8 Ω
Sd74.4 in²
Xmax0.67″
Vd49.8 in³ calc.
Mms201 g calc.
BL12.1 T·m calc.
EBP65 — sealed or ported calc.
Sensitivity, 1 W / 1 m86.2 dB calc.

General

Size12″
Voice coils2 Ω
RMS power750 W

Mounting dimensions

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