https://support.qsys.com/faq/faq-%7C-why-cant-i-connect-four-mxa910-mics-to-the-und4o
FAQ | Why can't I connect four MXA910 mics to the unD4O? - Q-SYS
Answer The Attero Tech by QSC unD4O is a Dante output device utilizing the Audinate UltimoX card. While the device can output four channels of audio from t