PSI PSI-8

8″ subwoofer · DVC · 400 W RMS

Fs 35 HzQts 0.97Vas 0.37 ft³Xmax 0.94″

Recommended box

For a sedan, one sub, 400 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 volume0.71 ft³ (20 L)
Qtc1.20
Fc43 Hz
F3 (−3 dB, no cabin gain)33 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 17 7/8″
Open sealed box in designer

Ported

Net volume1.20 ft³ (34 L)
Tuning (Fb)30 Hz
Port2 round ports Ø2 1/2″, 22 13/16″ long
Port velocity at 400 W113 ft/s
F3 (−3 dB, no cabin gain)24 Hz
Example box (outside)27″ × 15 3/4″ × 8 1/16″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs35 Hz
Qts0.97
Qes1.1
Qms8.5
Vas0.37 ft³
Re (one coil)3 Ω
Sd31 in²
Xmax0.94″
Vd29.3 in³ calc.
Mms112 g calc.
BL8.2 T·m calc.
EBP32 — suits sealed calc.
Sensitivity, 1 W / 1 m78.1 dB calc.

General

Size8″
Voice coilsDVC
RMS power400 W

Mounting dimensions

Ø8 1/2″cutout Ø7 1/4″mounting depth 5 1/2″magnet Ø≈ 4 11/16″
Cutout diameter7 1/4″
Mounting depth5 1/2″
Overall diameter8 1/2″

“≈” 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