Sundown Audio HZ-12 D4

12″ subwoofer · dual 4 Ω · 500 W RMS

Fs 31.7 HzQts 0.52Vas 1.92 ft³Xmax 0.55″

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 volume1.38 ft³ (39 L)
Qtc0.80
Fc49 Hz
F3 (−3 dB, no cabin gain)46 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 17 3/16″
Open sealed box in designer

Ported

Net volume3.07 ft³ (87 L)
Tuning (Fb)31 Hz
Portslot 2 3/16 × 14 5/16″, 23 1/2″ long
Port velocity at 500 W62 ft/s
F3 (−3 dB, no cabin gain)28 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 16 1/4″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs31.7 Hz
Qts0.52
Qes0.598
Qms3.77
Vas1.92 ft³
Re (one coil)3.07 Ω
Sd79.3 in²
Xmax0.55″
Vd43.7 in³ calc.
Mms172 g calc.
BL13.3 T·m calc.
EBP53 — sealed or ported calc.
Sensitivity, 1 W / 1 m86.6 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power500 W

Mounting dimensions

Ø12 1/2″cutout Ø11 3/16″mounting depth 6 5/16″magnet Ø6 1/8″
Cutout diameter11 3/16″
Mounting depth6 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: 79.3 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