Crossfire C7 8D2

8″ subwoofer · dual 2 Ω · 1,000 W RMS

Fs 49 HzQts 0.27Vas 0.15 ft³Xmax 0.39″

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 volume0.32 ft³ (9 L)
Qtc0.33
Fc59 Hz
F3 (−3 dB, no cabin gain)162 Hz
Example box (outside)11″ × 11″ × 8″
Open sealed box in designer

Ported

Net volume0.57 ft³ (16 L)
Tuning (Fb)30 Hz
Portslot 1 15/16 × 14 5/16″, 143 7/8″ long
Port velocity at 1,000 W48 ft/s
F3 (−3 dB, no cabin gain)152 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 14 5/16″

The volume and tuning are the recommendation, but the port doesn’t fit this example box. Size the box and port in the designer.

Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs49 Hz
Qts0.27
Qes0.29
Qms4.45
Vas0.15 ft³
Re (one coil)2 Ω
Sd29.3 in²
Xmax0.39″
Vd11.5 in³ calc.
Mms127 g calc.
BL16.4 T·m calc.
EBP169 — suits ported calc.
Sensitivity, 1 W / 1 m84.3 dB calc.

General

Size8″
Voice coilsdual 2 Ω
RMS power1,000 W

Mounting dimensions

Ø8 11/16″cutout ≈ Ø7 13/16″mounting depth 5 1/2″magnet Ø≈ 5 1/16″
Cutout diameter≈ 7 13/16″
Mounting depth5 1/2″
Overall 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 Crossfire 8″ models