Rockford Fosgate Punch P2D4-8

8″ subwoofer · dual 4 Ω · 250 W RMS

Fs 43 HzQts 0.52Vas 0.35 ft³Xmax 0.30″

Recommended box

For a sedan, one sub, 250 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)
Qtc0.76
Fc62 Hz
F3 (−3 dB, no cabin gain)61 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 9 1/4″
Open sealed box in designer

Ported

Net volume0.81 ft³ (23 L)
Tuning (Fb)35 Hz
Portround port Ø3″, 16 11/16″ long
Port velocity at 250 W116 ft/s
F3 (−3 dB, no cabin gain)31 Hz
Example box (outside)20 15/16″ × 15 3/4″ × 7 5/16″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs43 Hz
Qts0.52
Qes0.58
Qms5.4
Vas0.35 ft³
Re (one coil)3.45 Ω
Sd34.3 in²
Xmax0.30″
Vd10.4 in³ calc.
Mms96 g calc.
BL12.4 T·m calc.
EBP74 — sealed or ported calc.
Sensitivity, 1 W / 1 m83.3 dB calc.

General

Size8″
Voice coilsdual 4 Ω
RMS power250 W

Mounting dimensions

Ø≈ 8 5/16″cutout Ø7 1/8″mounting depth 4 3/4″magnet Ø≈ 4 5/8″
Cutout diameter7 1/8″
Mounting depth4 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 Rockford Fosgate 8″ models