Crescendo Audio Contralto 18 D1

18″ subwoofer · dual 1 Ω · 2,500 W RMS

Fs 22.5 HzQts 0.33Vas 9.57 ft³Xmax 1.02″

Recommended box

For a sedan, one sub, 2,500 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 volume2.31 ft³ (65.5 L)
Qtc0.74
Fc51 Hz
F3 (−3 dB, no cabin gain)52 Hz
Example box (outside)20 1/16″ × 20 1/16″ × 14 5/16″
Open sealed box in designer

Ported

Net volume5.83 ft³ (165 L)
Tuning (Fb)29 Hz
Portslot 4 1/2 × 19 7/16″, 40 5/16″ long
Port velocity at 2,500 W64 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 26 1/4″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs22.5 Hz
Qts0.33
Qes0.35
Qms5.01
Vas9.57 ft³
Re (one coil)≈ 0.85 Ω
Sd≈ 180.6 in²
Xmax1.02″
EBP64 — sealed or ported calc.
Sensitivity, 1 W / 1 m91.5 dB calc.

General

Size18″
Voice coilsdual 1 Ω
RMS power2,500 W

Mounting dimensions

Ø18 1/2″cutout Ø16 13/16″mounting depth 11 13/16″magnet Ø≈ 10 15/16″
Cutout diameter16 13/16″
Mounting depth11 13/16″
Overall diameter18 1/2″

“≈” 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