MVP8400 as a door phone

I have used it in an application with ethernet cameras that are streaming video to the touch panel. There is a speaker and mic at the door that is connected to a speaker and mic on the wall next to the wall-mounted touch panel run through and echo canceller. The person at the door presses a button which brings up the ethernet camera on screen, the audio connection is made and you talk to the person at the door. Pressing a button activates a mag lock switch that opens the door. Works great but you have to be standing near enough to the mic and speaker for it to pick up your voice. There was a system like this installed in a high end condo in Dallas that had 60+ units and multiple points of entry with multiple cameras that I did.

Added to the $$ million ++ cost of each condo....not much extra.

Your are correct - the speaker and mic installed next to the panel is handling all of the audio and the panel handles the interface to the door along with selecting the unit that needs to be dialed when you walk up to a door from the outside. Speaker and mic alone do not make up the doorphone - it is a combination of all that makes it work.