For a sedan, one sub, 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 Ported · SPL in dB at 1 W / 1 m, no cabin gain
Thiele/Small parameters
Fs
33 Hz
Qts
0.57
Qes
0.59
Qms
14.85
Vas
1.81 ft³
Re
3.1 Ω
Sd
79.1 in²
Xmax
0.29″
Vd
23 in³ calc.
Mms
167 g calc.
BL
13.5 T·m calc.
EBP
56 — sealed or ported calc.
Sensitivity, 1 W / 1 m
87 dB calc.
General
Size
12″
Voice coils
4 Ω
RMS power
250 W
Mounting dimensions
Cutout diameter
≈ 11 1/8″
Mounting depth
5 13/16″
“≈” 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.