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
34.5 Hz
Qts
0.57
Qes
0.6
Qms
10.8
Vas
1.21 ft³
Re
3.3 Ω
Sd
53.6 in²
Xmax
0.59″
Vd
31.7 in³ calc.
Mms
105 g calc.
BL
11.2 T·m calc.
EBP
58 — sealed or ported calc.
Sensitivity, 1 W / 1 m
85.7 dB calc.
General
Size
10″
Voice coils
4 Ω
RMS power
400 W
Mounting dimensions
Cutout diameter
9 5/16″
Mounting depth
5 13/16″
Overall diameter
11″
“≈” 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.