C-Series Matrix Crosspoints - Polycom SoundStructure C16 Design Manual

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12
UNGATED - Sound Reinforcement Processing
Mic or Line A/D Parametric
Analog
Input Gain Converter Equalization
Parametric
Equalization

C-Series Matrix Crosspoints

2 - 12
Recording/Ungated - Sound Reinforcement
Finally, the sound reinforcement recording input includes the echo and noise
cancellation and optional feedback elimination processing as shown in the fol-
lowing figure.
Non Linear
Acoustic Echo Noise
Processing
Cancellation Cancellation
Feedback
Cancellation
Acoustic Echo Noise Feedback
Cancellation Cancellation Cancellation
All three versions (conferencing, sound reinforcement, recording/ungated) of
the input signal processing can be used simultaneously in the matrix. The con-
ferencing version is typically used to send to remote participants, the sound
reinforcement version is typically used to send to the local loudspeaker sys-
tem, and the recording version is typically used for archiving the conference
audio content.
The audio matrix is used to create different mixes of input signals and submix
signals to be sent to output signals and submix signals. Matrix crosspoints gain
values are shown in dB where 0 dB means a signal value is unchanged. For
example, a crosspoint value of -6 dB will lower the signal gain by 6 dB before
it is summed with other signals. The matrix crosspoint gain can be adjusted in
0.1 dB steps between -100 and +20 dB and may also be completely muted. In
addition, the matrix crosspoint can also be negated/inverted so that the
crosspoint arithmetic creates a subtraction rather than an addition. The inver-
sion technique may be effective in difficult room reinforcement environments
by creating phase differences in alternating zones to add more gain before
feedback.
Matrix crosspoints associated with stereo channels have a balance or pan to
control mapping mono to stereo channels, stereo to mono channels, and stereo
to stereo channels.
The three different versions of the input processing - the ungated, conferenc-
ing, and sound reinforcement - are selected at the matrix crosspoint. The
SoundStructure Studio software allows the user to select which version of the
input signal processing at the matrix crosspoint. As will be shown in Chapter
4 Creating Designs, the different versions of the input processing will be rep-
resented with different background colors in the matrix crosspoint.
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
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