Fi Audio BTL3 12 D2

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

Fs 33.9 HzQts 0.26Vas 0.88 ft³Xmax 1.34″

Recommended box

For a sedan, one sub, 2,500 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

Net volume0.67 ft³ (19 L)
Qtc0.39
Fc51 Hz
F3 (−3 dB, no cabin gain)113 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 9 11/16″
Open sealed box in designer

Ported

Net volume1.41 ft³ (40 L)
Tuning (Fb)29 Hz
Port2 round ports Ø2 1/2″, 20 5/8″ long
Port velocity at 2,500 W334 ft/s
F3 (−3 dB, no cabin gain)101 Hz
Example box (outside)26″ × 15 3/4″ × 9 5/8″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs33.9 Hz
Qts0.26
Qes0.27
Qms6.11
Vas0.88 ft³
Re (one coil)1.8 Ω
Sd74.4 in²
Xmax1.34″
Vd99.6 in³ calc.
Mms290 g calc.
BL20.3 T·m calc.
EBP126 — suits ported calc.
Sensitivity, 1 W / 1 m87.5 dB calc.

General

Size12″
Voice coilsdual 2 Ω
RMS power2,500 W

Mounting dimensions

Ø12 1/2″cutout Ø11 1/8″mounting depth 7 1/4″magnet Ø≈ 7 1/4″
Cutout diameter11 1/8″
Mounting depth7 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