Crunch GTi84

8″ subwoofer · 4 Ω · 200 W RMS

Fs 42 HzQts 0.62Vas 0.38 ft³Xmax 0.30″

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 volume0.60 ft³ (17 L)
Qtc0.80
Fc54 Hz
F3 (−3 dB, no cabin gain)50 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 15 9/16″
Open sealed box in designer

Ported

Net volume1.27 ft³ (36 L)
Tuning (Fb)31 Hz
Port2 round ports Ø2 1/2″, 20″ long
Port velocity at 200 W89 ft/s
F3 (−3 dB, no cabin gain)27 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 7 1/4″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs42 Hz
Qts0.62
Qes0.678
Qms7.84
Vas0.38 ft³
Re3.8 Ω
Sd33.2 in²
Xmax0.30″
Vd9.8 in³ calc.
Mms86 g calc.
BL11.3 T·m calc.
EBP62 — sealed or ported calc.
Sensitivity, 1 W / 1 m82.7 dB calc.

General

Size8″
Voice coils4 Ω
RMS power200 W

Mounting dimensions

Ø8 7/16″cutout Ø7 3/16″mounting depth 3 1/16″magnet Ø≈ 4 11/16″
Cutout diameter7 3/16″
Mounting depth3 1/16″
Overall diameter8 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