For a sedan, one sub, 2,000 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
28.9 Hz
Qts
0.64
Qes
0.703
Qms
6.61
Vas
4.02 ft³
Re (one coil)
1.78 Ω
Sd
218 in²
Xmax
1.23″
Vd
268.6 in³ calc.
Mms
746 g calc.
BL
18.5 T·m calc.
EBP
41 — suits sealed calc.
Sensitivity, 1 W / 1 m
87.9 dB calc.
General
Size
18″
Voice coils
dual 2 Ω
RMS power
2,000 W
Mounting dimensions
Cutout (square, side)
≈ 16 9/16″
Mounting depth
≈ 8 1/4″
Magnet diameter
8 15/16″
“≈” 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.