Fi Audio Alpha v2 15 S2

15″ subwoofer · 2 Ω · 750 W RMS

Fs 39 HzQts 0.56Vas 2.55 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 volume2.44 ft³ (69 L)
Qtc0.80
Fc56 Hz
F3 (−3 dB, no cabin gain)52 Hz
Example box (outside)17 5/16″ × 17 5/16″ × 19 1/4″
Open sealed box in designer

Ported

Net volume4.87 ft³ (138 L)
Tuning (Fb)35 Hz
Portslot 3 1/8 × 16 11/16″, 17 9/16″ long
Port velocity at 750 W63 ft/s
F3 (−3 dB, no cabin gain)31 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 20 15/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs39 Hz
Qts0.56
Qes0.61
Qms6.89
Vas2.55 ft³
Re1.8 Ω
Sd125.6 in²
Xmax0.63″
Vd79.1 in³ calc.
Mms215 g calc.
BL12.5 T·m calc.
EBP64 — sealed or ported calc.
Sensitivity, 1 W / 1 m90.5 dB calc.

General

Size15″
Voice coils2 Ω
RMS power750 W

Mounting dimensions

Ø15 5/8″cutout Ø14 1/8″mounting depth 8 1/4″magnet Ø≈ 9 3/16″
Cutout diameter14 1/8″
Mounting depth8 1/4″
Overall diameter15 5/8″

“≈” 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 15″ models