Sundown Audio Zv6-18 D2

18″ subwoofer · dual 2 Ω · 3,250 W RMS

Fs 24.1 HzQts 0.40Vas 4.11 ft³Xmax 1.38″

Recommended box

For a sedan, one sub, 3,250 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 volume2.79 ft³ (79 L)
Qtc0.63
Fc38 Hz
F3 (−3 dB, no cabin gain)46 Hz
Example box (outside)19 11/16″ × 19 11/16″ × 17 5/16″
Open sealed box in designer

Ported

Net volume4.38 ft³ (124 L)
Tuning (Fb)26 Hz
Portslot 4 5/16 × 19 1/16″, 67″ long
Port velocity at 3,250 W67 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 26 5/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs24.1 Hz
Qts0.40
Qes0.427
Qms5.74
Vas4.11 ft³
Re (one coil)2 Ω
Sd176.9 in²
Xmax1.38″
Vd243.8 in³ calc.
Mms691 g calc.
BL22.1 T·m calc.
EBP56 — sealed or ported calc.
Sensitivity, 1 W / 1 m87.8 dB calc.

General

Size18″
Voice coilsdual 2 Ω
RMS power3,250 W

Mounting dimensions

Ø18 1/2″cutout Ø16 11/16″mounting depth 14 15/16″magnet Ø≈ 10 7/8″
Cutout diameter16 11/16″
Mounting depth14 15/16″
Overall diameter18 1/2″

The spec sheet's Sd of 254.5 in² is the area of a 18″ circle, not the cone's radiating area — not used.

Cone area (Sd) calculated from Fs, Vas and Mms: 176.9 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 18″ models