Infinity Beta EightX (8X)

8″ subwoofer · 4 Ω · 200 W RMS

Fs 31.7 HzQts 0.33Vas 1.19 ft³Xmax 0.37″

Recommended box

For a sedan, one sub, 200 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 volume0.32 ft³ (9 L)
Qtc0.73
Fc69 Hz
F3 (−3 dB, no cabin gain)72 Hz
Example box (outside)10 5/8″ × 10 5/8″ × 8 5/8″
Open sealed box in designer

Ported

Net volume0.78 ft³ (22 L)
Tuning (Fb)39 Hz
Port2 round ports Ø2 1/2″, 20 11/16″ long
Port velocity at 200 W69 ft/s
F3 (−3 dB, no cabin gain)39 Hz
Example box (outside)26 7/16″ × 15 3/4″ × 6 1/8″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs31.7 Hz
Qts0.33
Qes0.35
Qms6.8
Vas1.19 ft³
Re2.9 Ω
Sd33.5 in²
Xmax0.37″
Vd12.5 in³ calc.
Mms50 g calc.
BL9 T·m calc.
EBP90 — sealed or ported calc.
Sensitivity, 1 W / 1 m86.9 dB calc.

General

Size8″
Voice coils4 Ω
RMS power200 W

Mounting dimensions

Ø8 3/4″cutout Ø7 5/16″mounting depth 3 5/8″magnet Ø≈ 4 3/4″
Cutout diameter7 5/16″
Mounting depth3 5/8″
Overall diameter8 3/4″

“≈” 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

Other Infinity 8″ models