For a sedan, one sub, 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
31.2 Hz
Qts
0.33
Qes
0.35
Qms
5.64
Vas
1.80 ft³
Re
3.5 Ω
Sd
56.7 in²
Xmax
≈ 0.39″
Mms
97 g calc.
BL
13.8 T·m calc.
EBP
89 — sealed or ported calc.
Sensitivity, 1 W / 1 m
88.5 dB calc.
General
Size
10″
Voice coils
4 Ω
RMS power
250 W
Mounting dimensions
Cutout diameter
9 5/16″
Mounting depth
6″
Overall diameter
10 1/4″
Magnet diameter
5 13/16″
“≈” 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.