Sundown Audio HZS-12 D4

12″ subwoofer · dual 4 Ω · 500 W RMS

Fs 32.8 HzQts 0.48Vas 2.00 ft³Xmax 0.47″

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 volume1.13 ft³ (32 L)
Qtc0.80
Fc55 Hz
F3 (−3 dB, no cabin gain)52 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 14 9/16″
Open sealed box in designer

Ported

Net volume3.35 ft³ (95 L)
Tuning (Fb)31 Hz
Portslot 2 3/8 × 14 5/16″, 23 1/4″ long
Port velocity at 500 W61 ft/s
F3 (−3 dB, no cabin gain)28 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 17 1/2″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs32.8 Hz
Qts0.48
Qes0.564
Qms3.24
Vas2.00 ft³
Re (one coil)3.43 Ω
Sd86.2 in²
Xmax0.47″
Vd40.7 in³ calc.
Mms182 g calc.
BL15.1 T·m calc.
EBP58 — sealed or ported calc.
Sensitivity, 1 W / 1 m87.5 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power500 W

Mounting dimensions

Ø12 1/2″cutout Ø11 3/16″mounting depth 4 5/16″magnet Ø6 1/8″
Cutout diameter11 3/16″
Mounting depth4 5/16″
Overall diameter12 1/2″
Magnet diameter6 1/8″

The spec sheet's Sd of 114 in² is the area of a 12″ circle, not the cone's radiating area — not used.

Cone area (Sd) calculated from Fs, Vas and Mms: 86.2 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 12″ models