Cisco D9054 Installation And Operation Manual page 144

Setting Up the Dolby Digital Processing,
4. If relevant, enable the Bandwidth Lowpass Filter.
By enabling this filter you apply a low-pass filter to the input channel before the
Dolby Digital encoding. The default is On.
5. If relevant, enable the DC Highpass filter.
By enabling this filter you apply a DC high-pass filter to the input channel
before the Dolby Digital encoding. The default is On.
6. Select the Bit Stream Mode.
Use this field to select the type of information that the bit stream conveys. This is
an information-only field for the benefit of operators and other technicians and
does not affect the performance or behavior of the actual signal.
The current system choices are:
• Main Audio Service
• Main Audio Service: Dialog
• Visually Impaired
• Hearing Impaired
• Dialog
• Commentary
• Emergency Flash
The default is Main Audio Service.
7. Select the Dolby Surround Mode.
This option indicates whether or not a two-channel Dolby Digital bit stream is
providing a Dolby Surround encoded program. This setting is used only if you
have selected Stereo 2/0. Possible options are Dolby Surround Encoded, Not
Dolby Surround Encoded, or Not Indicated. The default is "No Indication".
8. Select to enable or disable LFE Enable.
This option enables low-frequency effects.
If you select Disable, it disables LFE for the audio input selections when setting
up the Dolby Digital Input Audio.
9. Select the LFE Lowpass Filter option. Select On to enable the digital 120 Hz low-
pass filtering to the LFE channel. Otherwise, select Off.
10. Select the Surround 90 degrees Phase-Shift. Select On to apply a 90-degree
phase shift to the surround channel. Otherwise, select Off.
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