I have a client that uses nextkast for their online radio and they recently came to me for live stream video. He uses Nextkast as his broadcast equipment and routes his microphone and other sound items through a mackie mixer. When we bring in the signal from the board, there is a major echo that is taking place. When he depresses the USB button on the board, the echo leaves but no sound from nextkast. Any ideas? Maybe it's a vmix error in the way we have his inputs... using usb mic (2).