SABINE FBX-901 is an easy-to-use automatic real-time feedback controller that increases the clarity and volume of your system. It automatically senses feedback in a sound system and determines its pitch. It then places one of nine micra-filters on the resonating frequency and eliminates the feedback in typically less than one second. Virtually every sound system will be improved with the FBX. Auditoriums and churches of all sizes will benefit from automatic, real-time feedback control.