CT Sounds HYDRO-8 D4

8″ subwoofer · dual 4 Ω · 300 W RMS

Fs 47.5 HzQts 0.60Vas 0.37 ft³Xmax 0.31″

Recommended box

For a sedan, one sub, 300 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 volume0.49 ft³ (14 L)
Qtc0.80
Fc63 Hz
F3 (−3 dB, no cabin gain)59 Hz
Example box (outside)10 5/8″ × 10 5/8″ × 12 3/16″
Open sealed box in designer

Ported

Net volume1.27 ft³ (36 L)
Tuning (Fb)34 Hz
Portslot 1 9/16 × 14 5/16″, 37 1/8″ long
Port velocity at 300 W51 ft/s
F3 (−3 dB, no cabin gain)30 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 5/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs47.5 Hz
Qts0.60
Qes0.668
Qms6.08
Vas0.37 ft³
Re (one coil)3.2 Ω
Sd35.2 in²
Xmax0.31″
Vd11.1 in³ calc.
Mms79 g calc.
BL10.6 T·m calc.
EBP71 — sealed or ported calc.
Sensitivity, 1 W / 1 m84.2 dB calc.

General

Size8″
Voice coilsdual 4 Ω
RMS power300 W

Mounting dimensions

Ø8 3/4″cutout Ø7 1/2″mounting depth 3 1/4″magnet Ø≈ 4 7/8″
Cutout diameter7 1/2″
Mounting depth3 1/4″
Overall diameter8 3/4″

“≈” 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 8″ models