For a sedan, one sub, 1,600 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
26.8 Hz
Qts
0.52
Qes
0.57
Qms
5.4
Vas
4.81 ft³
Re (one coil)
≈ 1.7 Ω
Sd
180.4 in²
Xmax
1.14″
Vd
206 in³ calc.
Mms
497 g calc.
BL
15.8 T·m calc.
EBP
47 — suits sealed calc.
Sensitivity, 1 W / 1 m
88.6 dB calc.
General
Size
18″
Voice coils
dual 2 Ω
RMS power
1,600 W
Mounting dimensions
Cutout diameter
16 7/8″
Mounting depth
10 11/16″
Overall diameter
18 1/2″
Magnet diameter
7 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.