Sundown Audio HZ-8 D4

8″ subwoofer · dual 4 Ω · 300 W RMS

Fs 41.3 HzQts 0.46Vas 0.27 ft³Xmax 0.55″

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 volume0.28 ft³ (8 L)
Qtc0.65
Fc58 Hz
F3 (−3 dB, no cabin gain)66 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 8 1/2″
Open sealed box in designer

Ported

Net volume0.60 ft³ (17 L)
Tuning (Fb)42 Hz
Portround port Ø2 1/2″, 10 3/4″ long
Port velocity at 300 W166 ft/s
F3 (−3 dB, no cabin gain)37 Hz
Example box (outside)14 5/16″ × 15 3/4″ × 7 11/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs41.3 Hz
Qts0.46
Qes0.549
Qms3
Vas0.27 ft³
Re (one coil)2.9 Ω
Sd31.2 in²
Xmax0.55″
Vd17.2 in³ calc.
Mms113 g calc.
BL12.5 T·m calc.
EBP75 — sealed or ported calc.
Sensitivity, 1 W / 1 m81.8 dB calc.

General

Size8″
Voice coilsdual 4 Ω
RMS power300 W

Mounting dimensions

Ø8 9/16″cutout Ø7 1/4″mounting depth 5 1/4″magnet Ø6 1/8″
Cutout diameter7 1/4″
Mounting depth5 1/4″
Overall diameter8 9/16″
Magnet diameter6 1/8″

The spec sheet's Sd of 53.4 in² is the area of a 8″ circle, not the cone's radiating area — not used.

Cone area (Sd) calculated from Fs, Vas and Mms: 31.2 in².

“≈” 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 Sundown Audio 8″ models