Polycom SoundStructure C16 Design Manual page 706

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12
C - 24
following figure. As discussed in an earlier section, the microphones should be
placed as close to the local participants as possible to minimize the amount of
background noise and reverberation.
The next figure shows the room of the previous figure with the directional
microphone pickup patterns and a 100 sq. ft. loudspeaker pattern overlaid.
Notice that the microphones are at the periphery of the loudspeaker coverage
pattern (to maximize the ERL of the room) and that while there is not 100%
loudspeaker coverage over the center of the table there is adequate coverage
of the audio in the room for both the seated participants and any overflow
seating for extra participants.
Table top microphone (8x)