For a sedan, one sub, 1,800 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
55.8 Hz
Qts
0.80
Qes
0.88
Qms
8.63
Vas
0.32 ft³
Re (one coil)
≈ 1.7 Ω
Sd
76.7 in²
Xmax
0.94″
Vd
72.5 in³ calc.
Mms
316 g calc.
BL
14.6 T·m calc.
EBP
63 — sealed or ported calc.
Sensitivity, 1 W / 1 m
84.5 dB calc.
General
Size
12″
Voice coils
dual 2 Ω
RMS power
1,800 W
Mounting dimensions
Cutout diameter
11″
Mounting depth
7″
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.