CT Sounds BIO-15 D4

15″ subwoofer · dual 4 Ω · 500 W RMS

Fs 31.2 HzQts 0.70Vas 4.17 ft³Xmax 0.30″

Recommended box

For a sedan, one sub, 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 volume2.90 ft³ (82 L)
Qtc1.09
Fc49 Hz
F3 (−3 dB, no cabin gain)39 Hz
Example box (outside)31 1/2″ × 17 11/16″ × 12 1/4″
Open sealed box in designer

Ported

Net volume4.94 ft³ (140 L)
Tuning (Fb)36 Hz
Portslot 2 3/8 × 16 5/16″, 10 15/16″ long
Port velocity at 500 W61 ft/s
F3 (−3 dB, no cabin gain)31 Hz
Example box (outside)31 1/2″ × 17 11/16″ × 20 1/2″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs31.2 Hz
Qts0.70
Qes0.803
Qms5.39
Vas4.17 ft³
Re (one coil)3.7 Ω
Sd127.7 in²
Xmax0.30″
Vd37.7 in³ calc.
Mms213 g calc.
BL13.9 T·m calc.
EBP39 — suits sealed calc.
Sensitivity, 1 W / 1 m88.5 dB calc.

General

Size15″
Voice coilsdual 4 Ω
RMS power500 W

Mounting dimensions

Ø15 3/8″cutout Ø13 15/16″mounting depth 6 7/16″magnet Ø≈ 9 1/16″
Cutout diameter13 15/16″
Mounting depth6 7/16″
Overall diameter15 3/8″

“≈” 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 CT Sounds 15″ models