Fi Audio BTL4 12 D2

12″ subwoofer · dual 2 Ω · 3,500 W RMS

Fs 27.8 HzQts 0.42Vas 0.96 ft³Xmax 1.30″

Recommended box

For a sedan, one sub, 3,500 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)
Qtc0.65
Fc43 Hz
F3 (−3 dB, no cabin gain)49 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)27 Hz
Port2 round ports Ø2 1/2″, 24 1/16″ long
Port velocity at 3,500 W343 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)26 3/8″ × 15 3/4″ × 9 5/8″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs27.8 Hz
Qts0.42
Qes0.45
Qms6.16
Vas0.96 ft³
Re (one coil)1.4 Ω
Sd74.4 in²
Xmax1.30″
Vd96.7 in³ calc.
Mms395 g calc.
BL14.6 T·m calc.
EBP62 — sealed or ported calc.
Sensitivity, 1 W / 1 m83.1 dB calc.

General

Size12″
Voice coilsdual 2 Ω
RMS power3,500 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