Hertz Hi-Energy HX 300 (SVC 4 ohm)

12″ subwoofer · 4 Ω · 600 W RMS

Fs 33 HzQts 0.47Vas 1.75 ft³Xmax 0.55″

Recommended box

For a sedan, one sub, 600 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 volume0.95 ft³ (27 L)
Qtc0.80
Fc56 Hz
F3 (−3 dB, no cabin gain)53 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 12 11/16″
Open sealed box in designer

Ported

Net volume3.00 ft³ (85 L)
Tuning (Fb)30 Hz
Portslot 2 3/8 × 14 5/16″, 28 11/16″ long
Port velocity at 600 W64 ft/s
F3 (−3 dB, no cabin gain)27 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 16 11/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs33 Hz
Qts0.47
Qes0.53
Qms4.4
Vas1.75 ft³
Re2.9 Ω
Sd77.8 in²
Xmax0.55″
Vd42.9 in³ calc.
Mms167 g calc.
BL13.8 T·m calc.
EBP62 — sealed or ported calc.
Sensitivity, 1 W / 1 m87.3 dB calc.

General

Size12″
Voice coils4 Ω
RMS power600 W

Mounting dimensions

Ø12 1/2″cutout Ø11 3/16″mounting depth 6 3/8″magnet Ø≈ 7 1/4″
Cutout diameter11 3/16″
Mounting depth6 3/8″
Overall diameter12 1/2″

Cone area (Sd) calculated from Fs, Vas and Mms: 77.8 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