American Bass VFLCOMP-1811

18″ subwoofer · dual 1 Ω · 5,000 W RMS

Fs 33.6 HzQts 0.48Vas 3.13 ft³Xmax 1.08″
The published specs don’t add up:

Recommended box

For a sedan, one sub, 5,000 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 volume2.12 ft³ (60 L)
Qtc0.75
Fc53 Hz
F3 (−3 dB, no cabin gain)52 Hz
Example box (outside)19 11/16″ × 19 11/16″ × 13 7/8″
Open sealed box in designer

Ported

Net volume5.69 ft³ (161 L)
Tuning (Fb)30 Hz
Port2 round ports Ø4″, 10 5/16″ long
Port velocity at 5,000 W341 ft/s
F3 (−3 dB, no cabin gain)27 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 20″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs33.6 Hz
Qts0.48
Qes0.537
Qms4.49
Vas3.13 ft³
Re (one coil)≈ 0.85 Ω
Sd180.2 in²
Xmax1.08″
Vd195.1 in³ calc.
Mms485 g calc.
BL12.7 T·m calc.
EBP63 — sealed or ported calc.
Sensitivity, 1 W / 1 m90 dB calc.

General

Size18″
Voice coilsdual 1 Ω
RMS power5,000 W

Mounting dimensions

Ø≈ 17 11/16″cutout Ø16 9/16″mounting depth 11 3/8″magnet Ø≈ 10 3/4″
Cutout diameter16 9/16″
Mounting depth11 3/8″

Cone area (Sd) calculated from Fs, Vas and Mms: 180.2 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