American Bass KING-1811

18″ subwoofer · dual 1 Ω · 6,500 W RMS

Fs 43.1 HzQts 0.77Vas 1.07 ft³Xmax 0.89″

Recommended box

For a sedan, one sub, 6,500 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

Net volume2.58 ft³ (73 L)
Qtc0.92
Fc51 Hz
F3 (−3 dB, no cabin gain)43 Hz
Example box (outside)20 1/16″ × 20 1/16″ × 15 5/8″
Open sealed box in designer

Ported

Net volume7.13 ft³ (202 L)
Tuning (Fb)26 Hz
Port2 round ports Ø5″, 18 1/8″ long
Port velocity at 6,500 W285 ft/s
F3 (−3 dB, no cabin gain)23 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 24 11/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs43.1 Hz
Qts0.77
Qes0.87
Qms6.9
Vas1.07 ft³
Re (one coil)0.8 Ω
Sd184.5 in²
Xmax0.89″
Vd163.4 in³ calc.
Mms901 g calc.
BL15 T·m calc.
EBP50 — suits sealed calc.
Sensitivity, 1 W / 1 m86.5 dB calc.

General

Size18″
Voice coilsdual 1 Ω
RMS power6,500 W

Mounting dimensions

Ø≈ 18 1/16″cutout Ø16 7/8″mounting depth 13 3/16″magnet Ø≈ 10 15/16″
Cutout diameter16 7/8″
Mounting depth13 3/16″

“≈” 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.

Data sources

Other American Bass 18″ models