Polycom SoundStructure C16 Design Manual page 40

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12
SR-Series Noise Cancellation Input Processing
Mic or Line Analog A/D Parametric
Input Converter Equalization
Gain
Parametric
Equalization
SR-Series Sound Reinforcement Input Processing
Mic or Line Analog A/D Parametric
Input Gain Converter Equalization
Parametric
Equalization
2 - 22
to paging zones that are not acoustically coupled to the microphone. This is the
default processing for microphone inputs when the automixed version of the
signal is selected.
Noise
Cancellation
Feedback
Cancellation
Noise Automatic
Cancellation Gain Control
Sound Reinforcement Version
The sound reinforcement version is processed with the parametric equaliza-
tion, noise cancellation, optional feedback elimination processing, automatic
gain control, dynamics processing, automixer, fader, delay, and input mute.
This is the path that is typically used for sending local audio to loudspeakers
in the room for sound reinforcement.
The automatic gain control on the sound reinforcement path is different from
the automatic gain control on the noise cancelled version of the signal in that
the sound reinforcement automatic gain control will not add gain to the signal.
In other words, the sound reinforcement AGC will only reduce the gain of the
signal and will not add gain to the signal. This restriction on the sound rein-
forcement AGC is to prevent the automatic gain control from reducing the
available potential acoustic gain before the onset of feedback.
Noise
Cancellation
Feedback
Cancellation
Noise Feedback Automatic
Cancellation Cancellation Gain Control
The automatic gain control on the sound reinforcement processing path will not add
gain to the signal, it will only reduce the gain of the signal.
AGC Dynamics Fader
Automatic Dynamics
Fader
Gain Control Processor
Automixer
Automatic Dynamics
Fader
Automixer
Gain Control Processor
Automatic Dynamics
Automixer Fader
Gain Control Processor
Dynamics
Automixer
Processor
AGC Dynamics Fader
Automatic Dynamics
Fader
Gain Control Processor
Automixer
Automatic Dynamics
Automixer Fader
Gain Control Processor
Automatic Dynamics
Automixer Fader
Gain Control Processor
Dynamics
Automixer
Processor
Delay Mute
Input to
Delay
Matrix
Input to
Delay
Matrix
Input to
Delay
Matrix
Fader Delay Mute
Delay Mute
Input to
Delay
Matrix
Input to
Delay
Matrix
Input to
Delay
Matrix
Fader Delay Mute
Recording/
Ungated
Noise Cancelled
Sound
Reinforcement
Recording/
Ungated
Noise Cancelled
Sound
Reinforcement