Hifonics ZST8D4

8″ subwoofer · dual 4 Ω · 250 W RMS

Fs 40.7 HzQts 0.60Vas 0.36 ft³Xmax 0.39″

Recommended box

For a sedan, one sub, 250 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 volume0.46 ft³ (13 L)
Qtc0.80
Fc54 Hz
F3 (−3 dB, no cabin gain)51 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 12 3/8″
Open sealed box in designer

Ported

Net volume1.20 ft³ (34 L)
Tuning (Fb)30 Hz
Port2 round ports Ø2 1/2″, 22 13/16″ long
Port velocity at 250 W95 ft/s
F3 (−3 dB, no cabin gain)26 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 7 1/16″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs40.7 Hz
Qts0.60
Qes0.67
Qms5.46
Vas0.36 ft³
Re (one coil)3.6 Ω
Sd33.2 in²
Xmax0.39″
Vd13.1 in³ calc.
Mms98 g calc.
BL11.6 T·m calc.
EBP61 — sealed or ported calc.
Sensitivity, 1 W / 1 m82.1 dB calc.

General

Size8″
Voice coilsdual 4 Ω
RMS power250 W

Mounting dimensions

Ø8 7/16″cutout Ø7 3/16″mounting depth 3 1/16″magnet Ø≈ 4 11/16″
Cutout diameter7 3/16″
Mounting depth3 1/16″
Overall diameter8 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 Hifonics 8″ models