Polycom SoundStructure C16 Design Manual page 108

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12
UNGATED - Sound Reinforcement Processing
Mic or Line Analog A/D Parametric
Input Converter Equalization
Gain
Parametric
Equalization
UNGATED - Low Delay Sound Reinforcement Processing
Mic or Line Analog A/D Parametric
Converter
Input Gain Equalization
Parametric
Equalization
5 - 26
The normal delay type for the Sound Reinforcement ungated type corresponds
to the processing paths that have been defined previously and shown in the
following figure.
Non Linear
Acoustic Echo Noise
Processing
Cancellation Cancellation
Feedback
Cancellation
Acoustic Echo Noise Feedback
Cancellation Cancellation Cancellation
The low delay type corresponds to a processing path that completely bypasses
the processing of the AEC and noise cancellation. Because these processing
blocks are not in the signal path, the signal has lower latency. The AEC and
noise cancellation add 16 msec of latency to the signal path. The resulting pro-
cessing path from bypassing the AEC and noise cancellation paths is shown in
the following figure.
Non Linear
Acoustic Echo Noise
Processing
Cancellation Cancellation
Feedback
Cancellation
Router
Feedback
Cancellation
When the low delay option is selected, the sound reinforcement and sound
reinforcement ungated processing paths will NOT have any echo and noise
cancellation processing. Only the conferencing and ungated conferencing versions
of the input processing will have echo and noise cancellation processing.
These two delay options are summarized in the following table.
Delay Type
Normal
Low delay
AGC Dynamics
Automatic Dynamics
Gain Control Processor
Automixer
Automatic Dynamics
Automixer
Gain Control Processor
Automatic Dynamics
Automixer
Gain Control Processor
Automatic Dynamics
Gain Control Processor
AGC Dynamics
Automatic Dynamics
Gain Control Processor
Router
Automixer
Automatic Dynamics
Automixer
Processor
Gain Control
Automatic Dynamics
Automixer
Gain Control Processor
Automatic Dynamics
Gain Control Processor
Meaning
The signal path includes the latency
associated with the echo and noise
cancellation signal path
The signal path does NOT include the
latency associated with the echo and
noise cancellation signal path. The echo
and noise cancellation blocks are
completely bypassed.
Fader Delay Mute
Input to
Fader Delay
Matrix
Input to
Fader Delay
Matrix
Input to
Fader Delay
Matrix
Fader Delay Mute
Fader Delay Mute
Input to
Fader Delay
Matrix
Input to
Fader Delay
Matrix
Input to
Fader Delay
Matrix
Fader Delay Mute
Recording/
Ungated
Conferencing
Sound
Reinforcement
Recording/
Ungated
Conferencing
Sound
Reinforcement