HERTZ MPS250S4 Car Audio Systems Owner’s Manual
ENCLOSURE DESIGN MP/MPS
In the following pages the Hertz Tech Team developed Sealed and Reflex designs for MP and MPS subwoofers. They are ready-to-build solutions, including the panel cut list, considering wood thickness 19mm (0.75in.) for MP and 16mm (0.63in.) for MPS series.
The Vb data is the net volume for the enclosure, i.e. it excludes the speaker volume, ports, any internal bracing and any other internal component.
The declared Fb is the actual tuning frequency of the box realized according to the ready-to-build solution. This geometry can not be accurately modeled using lumped parameter-based design software, hence those software may produce different results.
REGULAR
SHALLOW
Regular and Shallow variants for MPS series provide the same performance in just a different shape. Regular has the widest application while Shallow is the “solution” where low-depth is a matter.
Sealed enclosure designs provide optimally damped response for tight and accurate bass reproduction offering high energy in the range 20Hz-40Hz.
Where a high SPL bass is desired, and space is not a problem, the Reflex designs are the best choice concentrating most of energy in the 40Hz-80Hz range.
ENCLOSURE DESIGN MP 250 D2 / D4
| BOX TECH DATA | Vb | Fc / Fb | Qtc | External dimensions (Pic .1) | Mounting Hole – M | Wood Thickness | PxS-Port inner size | Lp-Port lenght | Damping Material | ||||
| W | H | D | P | S | |||||||||
| l (cu. ft.) | Hz | mm (in.) | mm (in.) | mm (in.) | mm (in.) | mm (in.) | mm (in.) | mm (in.) | mm (in.) | ||||
| MP 250 D2.3 Sealed (Fc) | 17 (0.60) | 50 | 0,85 | 450 (17.72) | 350 (13.78) | 190 (7.48) | 236 (9.29) | 19 (0.75) | – – | – – | – – | Pic. 1 | |
| MP 250 D4.3 Sealed (Fc) | 17 (0.60) | 47 | 0,82 | 450 (17.72) | 350 (13.78) | 190 (7.48) | 236 (9.29) | 19 (0.75) | – – | – – | – – | Pic. 1 | |
| MP 250 D2/D4.3 Reflex (Fb) | 24,5 (0.96) | 38 | – | 568 (22.36) | 330 (12.99) | 276 (10.87) | 236 (9.29) | 19 (0.75) | 292 (11.50) | 50 (1.97) | 670 (26.38) | Pic. 2 | |
SEALED BOX ASSEMBLY
DAMPING MATERIAL BOX ASSEMBLY AND SHAPE
This manual features the box assemblies and shapes which are easiest to create.
However, the bass frequency performance can be noticeably improved with different box shapes, assembly methods and construction materials.
| PANELS CUT LIST | A | Qty | B | Qty | C | Qty | |
| mm (in.) | Pcs | mm (in.) | Pcs | mm (in.) | Pcs | ||
| MP 250 D2/D4.3 Sealed | 450 X 350 (17.72 x 13.78) | 2 | 450 x 152 (17.72 x 5.98) | 2 | 312 x152 (12.28 x 5.98) | 2 | |
| MP 250 D2/D4.3 Reflex | 568 x 330 (22.36 x 12.99) | 2 | 568 x 238 (22.36 x 9.37) | 2 | 292 x 238 (11.50 x 9.37) | 2 |
| PANELS CUT LIST | A | Qty | B | Qty | C | Qty | |
| mm (in.) | Pcs | mm (in.) | Pcs | mm (in.) | Pcs | ||
| MP 300 D2/D4.3 Sealed | 450 X 360 (17.72 x 14.17) | 2 | 450 x 242 (17.72 x 9.53) | 2 | 322 x242 (12.68 x 9.53) | 2 | |
| MP 300 D2/D4.3 Reflex | 620 x 390 (24.41 x 15.35) | 2 | 620 x 292 (24.41 x 11.50) | 2 | 352 x 292 (13.86 x 11.50) |
DAMPING MATERIAL BOX ASSEMBLY AND SHAPE
This manual features the box assemblies and shapes which are easiest to create.
However, the bass frequency performance can be noticeably improved with different box shapes, assembly methods and construction materials.
SUGGESTED PORT POSITION/DIMENSION
ROUND SHAPE SUGGESTED AT THESE POINTS
| FILTER | Suggested Subsonic filter cut-off | Suggested Lo-pass filter cut-off | |
| MPS 250 S2/S4 Sealed | 15 Hz / 24dB Oct | 70-80 Hz / 24 db Oct | |
| MPS 250 S2/S4 Reflex | 20 Hz / 24dB Oct | 60-70 Hz / 24 db Oct |
Elettromedia
Hertz car audio systems | The Sound Experience
