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 Ported · SPL in dB at 1 W / 1 m, no cabin gain
Thiele/Small parameters
Fs
32.7 Hz
Qts
0.56
Qes
0.62
Qms
5.89
Vas
1.35 ft³
Re (one coil)
3.9 Ω
Sd
79.1 in²
Xmax
0.79″
Vd
62.2 in³ calc.
Mms
228 g calc.
BL
17.2 T·m calc.
EBP
53 — sealed or ported calc.
Sensitivity, 1 W / 1 m
85.3 dB calc.
General
Size
12″
Voice coils
dual 4 Ω
RMS power
600 W
Mounting dimensions
Cutout diameter
10 7/8″
Mounting depth
6 7/8″
Overall diameter
12 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.