Cisco Headend Digital Broadband Delivery System User Guide

2-8 

Audio Options 

4002178 Rev C 

The Audio Range option affects how the Dolby Digital decoder in the set-top 

presents the audio to the subscriber. When the original program encoder sends the 

audio level information to the set-top, the decoder in the set-top uses this 

information to compress the dynamic range of the audio in varying degrees.  

The amount of compression that is applied to the audio affects the output that your 

subscribers will hear. You can apply either a narrow, normal, or wide range of 

compression to the audio. You can select the best audio range for your subscribers, 

or allow your subscribers to select the range. Read the following information to 

determine the best range for your subscribers. 
Narrow 
With a narrow setting, the set-top performs the most extensive dynamic range 

compression available. The narrow setting boosts the dialog levels to more closely 

match analog channels. Most subscribers prefer the narrow setting for channel 

surfing and program viewing because it minimizes the difference in volume levels 

from channel to channel. The Narrow setting also works well for programs that have 

lots of loud and soft passages. 
Normal 
With a normal setting, the set-top preserves a large dynamic range with only a 

moderate amount of compression. The dialog level may be noticeably quieter on 

some channels, while the loudest passages will be noticeably louder. Most 

subscribers will not like the normal setting while channel surfing because the 

volume level can differ significantly from channel to channel. If your subscribers are 

using a home theater system that does not support a digital input, they may find that 

the Normal setting provides more of a movie-theater experience, but subscribers 

may have to adjust the volume more frequently.  
Wide 
The wide setting disables dynamic range compression. For multichannel sources, 

this setting reduces average signal levels to be significantly quieter than those for the 

normal setting.  
Important:  The wide setting is not recommended for subscriber use; this setting has 

been provided for testing purposes only. 

Enable this option to allow subscribers to select the audio range. We recommend that 

you select narrow as the default.