I am trying to design a system to run sound effects and music in multiple rooms of a haunted house. To make this work like I want, I need a mixer that will allow a mic connected to one sound card to be output on multiple cards, but I also need multiple mp3 players so I can control the music in each room individually. My goal for the mic is to be able to address the entire house or one room at a time. What would be the best way to accomplish this?