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Dolby® Encoding and Monitoring
RF Mode
The RF Mode control (7-6C) sets the DRC profile for the RF input on a television, usually through the antenna
output of a set top box. It typically uses a profile that employs a greater degree of compression and limiting
compared to Line Mode, as the RF Mode profile is often used for the "midnight mode" on decoders.
Profiles for both the Line Mode and RF Mode include:
Film Standard: Provides a 5dB null band around the loudness target and offers consistent loudness for most
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television content while preserving some dynamics
Film Light: Provides a 20dB null band around the loudness target and delivers a much more dynamic and
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theatrical presentation than Film Standard
Music Standard: Provides a 5dB null band around the loudness target and uses higher ratios than the Film
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profiles to more effectively manage highly produced music formats
Music Light: Provides a 12dB null band around the loudness target and uses lower ratios to preserve the
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dynamics of genres such as classical and jazz
Speech: Provides a 5dB null band but higher ratios to more effectively deal with the varying levels and high
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peaks typically found in speech
Downmix Gain Controls
The Downmix Gain controls (7-6D) can be individually set for the Lo/Ro Surround, Lo/Ro Center, Lt/Rt
Surround, and Lt/Rt Center channels.
Values for the Surround channels range from -1.5dB through -6.0dB and –Inf, which disables the Surround
channels. Values for the Center channels range from -6.0dB through +3.0db.
LFE Filter
The LFE Filter control (7-6E) applies low-pass filter (LPF) at 250Hz in the LFE channel.
Phase 90 Filter
The Phase 90 Filter control (7-6F) applies a 90-degree phase shift to the Surround channels, allowing the
downstream decoder to create a Lt/Rt downmix which can be rendered as an L, C, R, S signal by a Dolby Pro Logic
encoder.
Surround Attenuation
Enabling the Surround Attenuation control (7-6G) applies 3dB of attenuation to the Surround channels. This
is primarily included for use in cinema applications where multiple surround speakers sum acoustically and can
become louder than intended. The recommended setting for broadcast applications is "Disabled."
Chapter 7 | 41
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