Sundown Audio SA Classic 15 D4

15″ subwoofer · dual 4 Ω · 1,000 W RMS

Fs 36.4 HzQts 0.51Vas 2.38 ft³Xmax 0.75″

Recommended box

For a sedan, one sub, 1,000 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 volume1.66 ft³ (47 L)
Qtc0.80
Fc57 Hz
F3 (−3 dB, no cabin gain)54 Hz
Example box (outside)17 5/16″ × 17 5/16″ × 13 15/16″
Open sealed box in designer

Ported

Net volume5.05 ft³ (143 L)
Tuning (Fb)31 Hz
Portslot 3 3/8 × 16 11/16″, 24 5/8″ long
Port velocity at 1,000 W64 ft/s
F3 (−3 dB, no cabin gain)28 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 22 1/2″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs36.4 Hz
Qts0.51
Qes0.62
Qms2.94
Vas2.38 ft³
Re (one coil)3.5 Ω
Sd130.2 in²
Xmax0.75″
Vd97.4 in³ calc.
Mms284 g calc.
BL19.1 T·m calc.
EBP59 — sealed or ported calc.
Sensitivity, 1 W / 1 m89.2 dB calc.

General

Size15″
Voice coilsdual 4 Ω
RMS power1,000 W

Mounting dimensions

Ø15 1/2″cutout Ø14″mounting depth 7 11/16″magnet Ø7 13/16″
Cutout diameter14″
Mounting depth7 11/16″
Overall diameter15 1/2″
Magnet diameter7 13/16″

The spec sheet's Sd of 177 in² is the area of a 15″ circle, not the cone's radiating area — not used.

Cone area (Sd) calculated from Fs, Vas and Mms: 130.2 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 15″ models