Hertz Energy ES 300.5 (SVC 4 ohm)

12″ subwoofer · 4 Ω · 350 W RMS

35 HzFs, resonance
0.66Qts
1.71 ft³Vas
0.35″Xmax
350 WRMS

Recommended box

For a sedan, one sub, 350 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

smaller, tighter
1.80 ft³ (51 L)
Net volume
Qtc0.92
Fc49 Hz
F3 (−3 dB, no cabin gain)42 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 9 1/16″
Open sealed box in designer

Ported

deeper, louder
3.04 ft³ (86 L)
Net volume
Tuning (Fb)34 Hz
Portslot 1 15/16 × 14 5/16″, 17 1/16″ long
Port velocity at 350 W61 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 15 7/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs35 Hz
Qts0.66
Qes0.7
Qms11.4
Vas1.71 ft³
Re3.1 Ω
Sd78.5 in²
Xmax0.35″
Vd27.8 in³ calc.
Mms155 g calc.
BL12.3 T·m calc.
EBP50 — sealed or ported calc.
Sensitivity, 1 W / 1 m86.7 dB calc.

General

Size12″
Voice coils4 Ω
RMS power350 W

Mounting dimensions

Ø12 5/16″cutout Ø10 7/8″mounting depth 5 1/16″magnet Ø≈ 7 1/16″
Cutout diameter10 7/8″
Mounting depth5 1/16″
Overall diameter12 5/16″

Cone area (Sd) calculated from Fs, Vas and Mms: 78.5 in².

“≈” 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 Hertz 12″ models