I am seeking a solution for push to talk microphones and mixer that will support a class room of 20 people with one microphone for every two students. The system will interface with a videoconferencing system. The videoconferencing system provides RCA audio out.
Consider the Shure MX412D or MX418D mic connected to Shure SCM810 or SCM800 mixers.
Also, read Audio for Distance Learning at