For a sedan, one sub, 900 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
28.4 Hz
Qts
0.58
Qes
0.61
Qms
10.4
Vas
3.10 ft³
Re (one coil)
4 Ω
Sd
124 in²
Xmax
0.89″
Vd
109.8 in³ calc.
Mms
325 g calc.
BL
19.5 T·m calc.
EBP
47 — suits sealed calc.
Sensitivity, 1 W / 1 m
87.2 dB calc.
General
Size
15″
Voice coils
dual 4 Ω
RMS power
900 W
Mounting dimensions
Cutout diameter
13 5/8″
Mounting depth
7 5/16″
Overall diameter
15 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.