American Bass GF-1811

18″ subwoofer · dual 1 Ω · 3,000 W RMS

Fs 30.9 HzQts 0.51Vas 3.47 ft³Xmax 1.18″

Recommended box

For a sedan, one sub, 3,000 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

Net volume2.40 ft³ (68 L)
Qtc0.80
Fc48 Hz
F3 (−3 dB, no cabin gain)46 Hz
Example box (outside)19 11/16″ × 19 11/16″ × 15 5/16″
Open sealed box in designer

Ported

Net volume6.82 ft³ (193 L)
Tuning (Fb)28 Hz
Portslot 5 11/16 × 19 1/16″, 45 13/16″ long
Port velocity at 3,000 W65 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 32 5/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs30.9 Hz
Qts0.51
Qes0.592
Qms3.74
Vas3.47 ft³
Re (one coil)≈ 0.85 Ω
Sd176.2 in²
Xmax1.18″
Vd208.1 in³ calc.
Mms494 g calc.
BL11.7 T·m calc.
EBP52 — sealed or ported calc.
Sensitivity, 1 W / 1 m88.9 dB calc.

General

Size18″
Voice coilsdual 1 Ω
RMS power3,000 W

Mounting dimensions

Ø≈ 17 11/16″cutout Ø16 9/16″mounting depth 11 1/4″magnet Ø≈ 10 3/4″
Cutout diameter16 9/16″
Mounting depth11 1/4″

Cone area (Sd) calculated from Fs, Vas and Mms: 176.2 in².

“≈” 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