CT Sounds BIO-12 D4

12″ subwoofer · dual 4 Ω · 400 W RMS

Fs 35.2 HzQts 0.75Vas 1.74 ft³Xmax 0.30″

Recommended box

For a sedan, one sub, 400 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 volume1.77 ft³ (50 L)
Qtc1.05
Fc50 Hz
F3 (−3 dB, no cabin gain)40 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 8 15/16″
Open sealed box in designer

Ported

Net volume3.00 ft³ (85 L)
Tuning (Fb)35 Hz
Portslot 1 15/16 × 14 5/16″, 16 1/8″ long
Port velocity at 400 W61 ft/s
F3 (−3 dB, no cabin gain)30 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 15 3/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs35.2 Hz
Qts0.75
Qes0.842
Qms6.56
Vas1.74 ft³
Re (one coil)3.7 Ω
Sd77.3 in²
Xmax0.30″
Vd22.8 in³ calc.
Mms146 g calc.
BL11.9 T·m calc.
EBP42 — suits sealed calc.
Sensitivity, 1 W / 1 m86.1 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power400 W

Mounting dimensions

Ø12 7/16″cutout Ø11″mounting depth 5 3/8″magnet Ø≈ 7 3/16″
Cutout diameter11″
Mounting depth5 3/8″
Overall diameter12 7/16″

“≈” 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 CT Sounds 12″ models