Designing With Hdx Digital Microphone Arrays - Polycom SoundStructure C16 Design Manual

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12

Designing With HDX Digital Microphone Arrays

6 - 12
It is also possible to limit the minimum and maximum user gain settings via
SoundStructure Studio software by using the min and max gain limits on the
fader control. This can be done graphically on the channels page as shown in
the following figure or via the SoundStructure API. See the fader command for
the syntax of how to use the min and max user limits.
Because SoundStructure systems receive volume change requests from the
HDX and with pre 1.3 SoundStructure firmware do not send volume messages
to the Polycom HDX, any volume limit set on the SoundStructure system will
not be recognized by the HDX. This means that while the user adjusts volume
on the Polycom HDX, it will appear as the volume continues to change on the
Polycom HDX UI although a volume limit may have already been reached
within the SoundStructure system which would prevent the system from get-
ting any louder in the room.
SoundStructure devices with version 1.3 firmware or later will use events to
both receive and set the HDX volume parameter. See Chapter 9 for informa-
tion on using events with an HDX video codec.
Each HDX digital microphone array has three microphone elements and must
be thought of as three microphone inputs. As a result, each HDX digital
microphone requires the processing of three SoundStructure analog input
channels. In other words, for Because each digital microphone array is
represented as three microphones, every microphone array and its respective
three microphone elements can be used independently with a SoundStructure
device. This means that several HDX microphone arrays can be linked
together and used, for example, in room combining applications where one or
more microphone arrays are in one room and one or more microphone arrays