Hopefully someone can help answer this for me. I will try to summarize the main parts of the system.
We have an installation where we have Audio Technica boundary mics mounted to the ceiling. These are connected to a Soundstructure.
The SS has an internal VOIP card and we also have a Cisco VC codec. The mics are mixed down and feed both the internal VOIP card and provide a single mic feed for the codec.
We then use the ceiling mics in either TC mode or VC mode depending on user preference.
The issue is that in VC mode the mic pickup is perfect but in TC mode it doesn't matter how much we try we cant adjust the mics to pick up the user without increasing the gain too much at which point you can hear everything!
In essence the codec is doing a better job than the VOIP card of coping with the pickup distance.
I dont consider myself a novice but this is proving impossible to overcome.