Hertz Mille Pro MPS 300 S4 (shallow, SVC 4 ohm)

12″ subwoofer · 4 Ω · 500 W RMS

Fs 23 HzQts 0.42Vas 2.19 ft³Xmax 0.66″

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 volume	0.85 ft³ (24 L)
Qtc	0.80
Fc	44 Hz
F3 (−3 dB, no cabin gain)	42 Hz
Example box (outside)	14 3/16″ × 14 3/16″ × 11 9/16″

Open sealed box in designer

Ported

Net volume	2.72 ft³ (77 L)
Tuning (Fb)	25 Hz
Port	slot 1 15/16 × 14 5/16″, 40″ long
Port velocity at 500 W	61 ft/s
F3 (−3 dB, no cabin gain)	23 Hz
Example box (outside)	31 1/2″ × 15 3/4″ × 16 3/16″

Open ported box in designer

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

Thiele/Small parameters

Fs	23 Hz
Qts	0.42
Qes	0.45
Qms	6.3
Vas	2.19 ft³
Re	3.4 Ω
Sd	83.9 in²
Xmax	0.66″
Vd	55.5 in³ calc.
Mms	320 g calc.
BL	18.7 T·m calc.
EBP	51 — sealed or ported calc.
Sensitivity, 1 W / 1 m	84.3 dB calc.

General

Size	12″
Voice coils	4 Ω
RMS power	500 W

Mounting dimensions

Cutout diameter	11 1/8″
Mounting depth	3 1/2″
Overall diameter	12 1/2″
Magnet diameter	6 1/8″

“≈” 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

Hertz Cento CS 300 S2 (SVC 2 ohm) 12″ · 2 Ω
Hertz Cento CS 300 S4 (SVC 4 ohm) 12″ · 4 Ω
Hertz Dieci DS 30.3 (SVC 4 ohm) 12″ · 4 Ω
Hertz Dieci DS 300.3 (SVC 4 ohm) 12″ · 4 Ω
Hertz Energy ES 300.5 (SVC 4 ohm) 12″ · 4 Ω
Hertz Energy ES 300D.5 (DVC 4+4 ohm) 12″ · dual 4 Ω
Hertz Energy ES F30.5 (free-air/shallow, SVC 4 ohm) 12″ · 4 Ω
Hertz Hi-Energy HX 300 (SVC 4 ohm) 12″ · 4 Ω
Hertz Hi-Energy HX 300 D (DVC 4+4 ohm) 12″ · dual 4 Ω
Hertz Mille Pro MP 300 D2.3 (DVC 2+2 ohm) 12″ · dual 2 Ω
Hertz Mille Pro MP 300 D4.3 (DVC 4+4 ohm) 12″ · dual 4 Ω
Hertz Mille Pro MPS 300 S2 (shallow, SVC 2 ohm) 12″ · 2 Ω