Audioque HDC318-A D1

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

Fs 31 HzQts 0.43Vas 3.85 ft³

Recommended box

For a sedan, one sub, 1,000 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 volume1.70 ft³ (48 L)
Qtc0.79
Fc56 Hz
F3 (−3 dB, no cabin gain)54 Hz
Example box (outside)19 11/16″ × 19 11/16″ × 11 11/16″
Open sealed box in designer

Ported

Net volume5.26 ft³ (149 L)
Tuning (Fb)31 Hz
Portslot 2 15/16 × 19 1/16″, 23 9/16″ long
Port velocity at 1,000 W64 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 20 13/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs31 Hz
Qts0.43
Qes0.5
Qms3.3
Vas3.85 ft³
Re (one coil)≈ 0.85 Ω
Sd184.5 in²
Xmax≈ 0.39″
Mms485 g calc.
BL12.7 T·m calc.
EBP62 — sealed or ported calc.
Sensitivity, 1 W / 1 m90.1 dB calc.

General

Size18″
Voice coilsdual 1 Ω
RMS power1,000 W

Mounting dimensions

Ø≈ 17 11/16″cutout Ø16 1/2″mounting depth ≈ 8 1/4″magnet Ø8 11/16″
Cutout diameter16 1/2″
Mounting depth≈ 8 1/4″
Magnet diameter8 11/16″

“≈” 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 Audioque 18″ models