Hertz Energy ES F30.5 (free-air/shallow, SVC 4 ohm)
12″ subwoofer · 4 Ω · 350 W RMS
Fs 38 HzQts 0.60Vas 2.12 ft³Xmax 0.24″
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
| Net volume | 1.84 ft³ (52 L) |
|---|---|
| Qtc | 0.89 |
| Fc | 56 Hz |
| F3 (−3 dB, no cabin gain) | 49 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 9 3/16″ |
Ported
| Net volume | 3.11 ft³ (88 L) |
|---|---|
| Tuning (Fb) | 38 Hz |
| Port | slot 1 15/16 × 14 5/16″, 12 7/16″ long |
| Port velocity at 350 W | 61 ft/s |
| F3 (−3 dB, no cabin gain) | 34 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 15 5/16″ |
Thiele/Small parameters
| Fs | 38 Hz |
|---|---|
| Qts | 0.60 |
| Qes | 0.7 |
| Qms | 4.44 |
| Vas | 2.12 ft³ |
| Re | 2.9 Ω |
| Sd | 79.9 in² |
| Xmax | 0.24″ |
| Vd | 18.9 in³ calc. |
| Mms | 110 g calc. |
| BL | 10.4 T·m calc. |
| EBP | 54 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 88.7 dB calc. |
General
| Size | 12″ |
|---|---|
| Voice coils | 4 Ω |
| RMS power | 350 W |
Mounting dimensions
| Cutout diameter | 10 7/8″ |
|---|---|
| Mounting depth | 3 3/4″ |
| Overall diameter | 12 1/16″ |
Cone area (Sd) calculated from Fs, Vas and Mms: 79.9 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
- web.archive.org/web/20170706021729/http://www.hertzaudiovideo.com/wp-content/upl
- web.archive.org/web/20180101085123/http://www.hertzaudiovideo.com/car-audio-subw
Other Hertz 12″ models
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