Polycom SoundStructure C16 Design Manual page 94

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12
C-Series Input Processing
Mic or Line Analog A/D Parametric
Input Converter Equalization
Gain
level_pre
5 - 14
to the SoundStructure device, however the meters will be most responsive
over the Ethernet interface. If meters are viewed over the RS-232 interface, it is
recommended that the highest data rate of 115,200 baud be used to minimize
any lag between registering for meters and having the meter information dis-
played on the screen.
Meter Types
There are typically two types for meters that are available for each input chan-
nel - a level that is before, or pre, any processing known as a level_pre and a
level that is after, or post, any input processing known as level_post.
The level_pre meter always shows the signal level just after the A/D con-
verter. This meter shows the effect of the analog signal gain before any digital
processing takes place as shown in the following figure. Chapter 7 discusses
how the analog gain should be set for best performance. The level_pre for all
input signals is shown in the following figure.
Router
Non Linear
Acoustic Echo Noise
Processing
Cancellation Cancellation
Feedback
Cancellation
e A/D
Analog
Converter
Gain
level_pre
Within SoundStructure Studio, the level_pre signal meter is adjacent to the
analog input gain slider in SoundStructure Studio, as shown in the following
figure. Adjustments to the gain slider will be reflected in the meter - add more
gain and the meter will show more signal activity. Lower the gain and the
AGC Dynamics Fader
Automatic Dynamics
Fader
Gain Control Processor
Automixer
Automatic Dynamics
Fader
Automixer
Gain Control Processor
Automatic Dynamics
Automixer Fader
Gain Control Processor
Parametric
Equalization
Delay Mute
Input to Recording/
Delay
Matrix
Ungated
Input to
Conferencing
Delay
Matrix
Sound
Input to
Delay
Matrix Reinforcement