Rockville W8K9D4

8″ subwoofer · dual 4 Ω · 500 W RMS

Fs 39.5 HzQts 0.47Vas 0.17 ft³Xmax 0.39″

Recommended box

For a sedan, one sub, 500 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 volume0.34 ft³ (9.5 L)
Qtc0.58
Fc49 Hz
F3 (−3 dB, no cabin gain)63 Hz
Example box (outside)11″ × 11″ × 8 3/8″
Open sealed box in designer

Ported

Net volume0.57 ft³ (16 L)
Tuning (Fb)29 Hz
Portslot 1 15/16 × 14 5/16″, 154 5/16″ long
Port velocity at 500 W32 ft/s
F3 (−3 dB, no cabin gain)26 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 15″

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
2030405060801001502005460667278HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs39.5 Hz
Qts0.47
Qes0.553
Qms3.23
Vas0.17 ft³
Re (one coil)3.8 Ω
Sd29.2 in²
Xmax0.39″
Vd11.5 in³ calc.
Mms168 g calc.
BL16.9 T·m calc.
EBP71 — sealed or ported calc.
Sensitivity, 1 W / 1 m79.4 dB calc.

General

Size8″
Voice coilsdual 4 Ω
RMS power500 W

Mounting dimensions

Ø≈ 8 15/16″cutout Ø7 3/4″mounting depth 5 7/8″magnet Ø5 11/16″
Cutout diameter7 3/4″
Mounting depth5 7/8″
Magnet diameter5 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 Rockville 8″ models