Rockford Fosgate Punch P1S4-8

8″ subwoofer · 4 Ω · 200 W RMS

Fs 40 HzQts 0.43Vas 0.42 ft³Xmax 0.31″
The published specs don’t add up:

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 volume0.28 ft³ (8 L)
Qtc0.68
Fc63 Hz
F3 (−3 dB, no cabin gain)69 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 8 1/2″
Open sealed box in designer

Ported

Net volume0.64 ft³ (18 L)
Tuning (Fb)37 Hz
Portround port Ø2 1/2″, 13 1/2″ long
Port velocity at 200 W126 ft/s
F3 (−3 dB, no cabin gain)35 Hz
Example box (outside)17 3/4″ × 15 3/4″ × 6 7/8″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs40 Hz
Qts0.43
Qes0.48
Qms4
Vas0.42 ft³
Re3.8 Ω
Sd32.7 in²
Xmax0.31″
Vd10.3 in³ calc.
Mms83 g calc.
BL12.9 T·m calc.
EBP83 — sealed or ported calc.
Sensitivity, 1 W / 1 m84 dB calc.

General

Size8″
Voice coils4 Ω
RMS power200 W

Mounting dimensions

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

“≈” 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