16 ADDITIONAL INFORMATION
Optimum surround sound for different sources
There are currently various types of
2Types of multi-channel signals
Dolby Digital, Dolby Pro Logic, DTS, high definition
“Source” here does not refer to the type of signal (format) but the recorded content. Sources can be divided into two major categories.
2Types of sources
• Movie audio | Signals created to be played in movie theaters. In general sound is recorded to be played in movie theaters equipped |
| with multiple surround speakers, regardless of the format (Dolby Digital, DTS, etc.). |
Movie theater sound field
FL | SW | C | FR |
| SL |
| SR |
Listening room sound field
FL |
| SW |
| C |
| FR |
SL SR
In this case it is important to achieve the same sense of expansion as in a movie theater with the surround channels. To do so, in some cases the number of surround speakers is increased (to four or eight) or speakers with bipolar or dipolar properties are used.
Multiple surround speakers
• Other types of audio These signals are designed to recreate a 360° sound field using three to five speakers.
FL | SW | C | FR |
SL |
|
| SR |
In this case the speakers should surround the listener from all sides to create a uniform sound field from 360°. Ideally the surround speakers should function as “point” sound sources in the same way as the front speakers.
These two types of sources thus have different properties, and different speaker settings, particularly for the surround speakers, are required in order to achieve the ideal sound.
The
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