For a sedan, one sub, 1,250 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
50 Hz
Qts
0.39
Qes
0.448
Qms
2.9
Vas
0.33 ft³
Re (one coil)
2 Ω
Sd
76.1 in²
Xmax
1.18″
Vd
89.9 in³ calc.
Mms
371 g calc.
BL
22.8 T·m calc.
EBP
112 — suits ported calc.
Sensitivity, 1 W / 1 m
86.2 dB calc.
General
Size
12″
Voice coils
dual 2 Ω
RMS power
1,250 W
Mounting dimensions
Cutout diameter
11 1/8″
Mounting depth
7 1/16″
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.