Skar Audio DDX-12 D4

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

Fs 34.2 HzQts 0.37Vas 0.91 ft³Xmax 0.59″
The published specs don’t add up:

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 volume0.71 ft³ (20 L)
Qtc0.56
Fc52 Hz
F3 (−3 dB, no cabin gain)71 Hz
Example box (outside)14 9/16″ × 14 9/16″ × 9 9/16″
Open sealed box in designer

Ported

Net volume1.52 ft³ (43 L)
Tuning (Fb)30 Hz
Portslot 1 3/4 × 14 5/16″, 45 1/2″ long
Port velocity at 1,000 W81 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 11 1/2″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs34.2 Hz
Qts0.37
Qes0.41
Qms3.9
Vas0.91 ft³
Re (one coil)≈ 3.4 Ω
Sd79.1 in²
Xmax0.59″
Vd46.7 in³ calc.
Mms309 g calc.
BL23.4 T·m calc.
EBP83 — sealed or ported calc.
Sensitivity, 1 W / 1 m86 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power1,000 W

Mounting dimensions

Ø12 9/16″cutout Ø11 1/4″mounting depth 6 9/16″magnet Ø7 5/8″
Cutout diameter11 1/4″
Mounting depth6 9/16″
Overall diameter12 9/16″
Magnet diameter7 5/8″

“≈” 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 12″ models