Skar Audio SDR-15 D4

15″ subwoofer · dual 4 Ω · 600 W RMS

Fs 29 HzQts 0.52Vas 3.50 ft³Xmax 0.53″
The published specs don’t add up:

Recommended box

For a sedan, one sub, 600 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 volume2.51 ft³ (71 L)
Qtc0.80
Fc45 Hz
F3 (−3 dB, no cabin gain)42 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 10 5/8″
Open sealed box in designer

Ported

Net volume4.52 ft³ (128 L)
Tuning (Fb)30 Hz
Portslot 2 3/8 × 16 11/16″, 20 3/4″ long
Port velocity at 600 W63 ft/s
F3 (−3 dB, no cabin gain)27 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 19 9/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs29 Hz
Qts0.52
Qes0.57
Qms5.47
Vas3.50 ft³
Re (one coil)≈ 3.4 Ω
Sd117 in²
Xmax0.53″
Vd62.2 in³ calc.
Mms245 g calc.
BL16.3 T·m calc.
EBP51 — sealed or ported calc.
Sensitivity, 1 W / 1 m88.3 dB calc.

General

Size15″
Voice coilsdual 4 Ω
RMS power600 W

Mounting dimensions

Ø≈ 15 3/16″cutout Ø14″mounting depth 7 5/8″magnet Ø6 1/8″
Cutout diameter14″
Mounting depth7 5/8″
Magnet diameter6 1/8″

“≈” 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 Skar Audio 15″ models