Hifonics ZXT18D2

18″ subwoofer · dual 2 Ω · 4,000 W RMS

Fs 36 HzQts 0.62Vas 3.07 ft³Xmax 0.91″

Recommended box

For a sedan, one sub, 4,000 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 volume4.10 ft³ (116 L)
Qtc0.83
Fc48 Hz
F3 (−3 dB, no cabin gain)43 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 14 3/8″
Open sealed box in designer

Ported

Net volume6.96 ft³ (197 L)
Tuning (Fb)32 Hz
Portslot 5 7/8 × 19 7/16″, 34 1/4″ long
Port velocity at 4,000 W74 ft/s
F3 (−3 dB, no cabin gain)28 Hz
Example box (outside)31 1/2″ × 20 7/8″ × 30″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs36 Hz
Qts0.62
Qes0.73
Qms4.29
Vas3.07 ft³
Re (one coil)2 Ω
Sd179.8 in²
Xmax0.91″
Vd162.8 in³ calc.
Mms428 g calc.
BL16.3 T·m calc.
EBP49 — suits sealed calc.
Sensitivity, 1 W / 1 m89.5 dB calc.

General

Size18″
Voice coilsdual 2 Ω
RMS power4,000 W

Mounting dimensions

Ø18 1/4″cutout Ø16 7/8″mounting depth 10 15/16″magnet Ø≈ 10 15/16″
Cutout diameter16 7/8″
Mounting depth10 15/16″
Overall diameter18 1/4″

“≈” 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