Phoenix Gold SX18S4 (SVC 4 ohm)

8″ subwoofer · 4 Ω · 200 W RMS

Fs 40.2 HzQts 0.66Vas 0.33 ft³Xmax 0.59″

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 volume0.64 ft³ (18 L)
Qtc0.81
Fc49 Hz
F3 (−3 dB, no cabin gain)46 Hz
Example box (outside)10 5/8″ × 10 5/8″ × 15 1/16″
Open sealed box in designer

Ported

Net volume1.27 ft³ (36 L)
Tuning (Fb)29 Hz
Port2 round ports Ø2 1/2″, 23 1/16″ long
Port velocity at 200 W89 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 7 3/8″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs40.2 Hz
Qts0.66
Qes0.714
Qms7.96
Vas0.33 ft³
Re3.8 Ω
Sd32.6 in²
Xmax0.59″
Vd19.2 in³ calc.
Mms106 g calc.
BL11.9 T·m calc.
EBP56 — sealed or ported calc.
Sensitivity, 1 W / 1 m81.2 dB calc.

General

Size8″
Voice coils4 Ω
RMS power200 W

Mounting dimensions

Ø≈ 8 7/16″cutout Ø7 5/16″mounting depth 4 5/16″magnet Ø≈ 4 3/4″
Cutout diameter7 5/16″
Mounting depth4 5/16″

“≈” 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 Phoenix Gold 8″ models