B2 Audio ISx18 D1

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

Fs 30.3 HzQts 0.74Vas 5.10 ft³Xmax 0.98″

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 volume4.13 ft³ (117 L)
Qtc1.11
Fc45 Hz
F3 (−3 dB, no cabin gain)36 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 14 3/4″
Open sealed box in designer

Ported

Net volume6.99 ft³ (198 L)
Tuning (Fb)34 Hz
Portslot 3 3/8 × 19 1/16″, 14 1/2″ long
Port velocity at 1,000 W62 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 25 3/16″
Open ported box in designer
2030405060801001502007278849096102HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs30.3 Hz
Qts0.74
Qes0.84
Qms6.2
Vas5.10 ft³
Re (one coil)0.95 Ω
Sd≈ 180.6 in²
Xmax0.98″
EBP36 — suits sealed calc.
Sensitivity, 1 W / 1 m88.8 dB calc.

General

Size18″
Voice coilsdual 1 Ω
RMS power1,000 W

Mounting dimensions

Ø18 7/16″cutout ≈ Ø16 9/16″mounting depth ≈ 8 1/4″magnet Ø≈ 10 3/4″
Cutout diameter≈ 16 9/16″
Mounting depth≈ 8 1/4″
Overall diameter18 7/16″

“≈” 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 B2 Audio 18″ models