For a sedan, one sub, 400 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
28.7 Hz
Qts
0.49
Qes
0.505
Qms
13.93
Vas
1.25 ft³
Re (one coil)
1.91 Ω
Sd
54.2 in²
Xmax
0.53″
Vd
28.6 in³ calc.
Mms
151 g calc.
BL
10.1 T·m calc.
EBP
57 — sealed or ported calc.
Sensitivity, 1 W / 1 m
84.2 dB calc.
General
Size
10″
Voice coils
dual 2 Ω
RMS power
400 W
Mounting dimensions
Cutout diameter
9 1/8″
Mounting depth
3 7/16″
Overall diameter
10 11/16″
Magnet diameter
6 3/8″
“≈” 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.