Network collaboration system with private voice chat

A network collaboration system facilitates collaborations between network clients having access to a digital network. The system uses audio mixes to provide different levels of voice conferences between the meeting participants. In a main collaboration, those participating in the main collaboration receive an audio output that includes audio inputs from the other participants. A subset group of clients may also have a voice chat, in which their audio inputs are removed from the outputs delivered to the clients not participating in the voice chat. Meanwhile, the participants in the voice chat hear each other at full volume, but hear the collaborators who are not part of the voice chat at a reduced volume.