For a sedan, one sub, 1,200 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
30.7 Hz
Qts
0.41
Qes
0.456
Qms
4.38
Vas
1.26 ft³
Re (one coil)
1.9 Ω
Sd
79.1 in²
Xmax
0.55″
Vd
43.6 in³ calc.
Mms
276 g calc.
BL
14.9 T·m calc.
EBP
67 — sealed or ported calc.
Sensitivity, 1 W / 1 m
85.6 dB calc.
General
Size
12″
Voice coils
dual 2 Ω
RMS power
1,200 W
Mounting dimensions
Cutout diameter
10 15/16″
Mounting depth
6 3/4″
Overall diameter
12 1/2″
“≈” 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.