Polycom SoundStructure C16 Design Manual page 38

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12
A/D
Mic or Line Analog
Input Gain Converter
2 - 20
Each analog input signal has an analog gain stage that is used to adjust the gain
of the input signal to the SoundStructure's nominal signal level of 0 dBu. The
analog gain stage can provide from -20 to 64 dB of analog gain in 0.5 dB incre-
ments. There is also an option to enable 48 V phantom power on each input.
Finally the analog input signal is digitized and ready for processing.
SR-Series Input Processing
Router
Parametric Noise
Equalization Cancellation
Feedback
Cancellation
Mic or Line
Input
Continuing through the signal path as shown in the next figure, the input
signal processing continues through the AGC (automatic gain control),
dynamics processing, an automixer, an audio fader, and finally through the
input delay.
Each analog input signal will be processed to generate three different versions
of the processed input signal that can be used simultaneously in the matrix:
1. Noise cancelled version,
2. Sound reinforcement version, and
3. Recording/ungated version
The AGC, dynamics processor, and input fader are linked together on all three
audio paths and apply the same gain to the signal paths based on an analysis
of the signal earlier in the signal path.
AGC Dynamics Fader
Automatic Dynamics
Fader
Gain Control Processor
Automixer
Dynamics
Automatic
Automixer Fader
Gain Control Processor
SR-Series Input Processing
Automatic Dynamics
Automixer Fader
Gain Control Processor
Analog A/D
Converter
Gain
Delay
Input to
Delay
Matrix
Input to
Delay
Matrix
Input to
Delay
Matrix
Parametric Noise
Equalization Cancellation
Feedback
Cancellation
Rou