PAIR WITH MULTEQ-X - The Audyssey ACM1-X calibration microphone is exclusively designed for use with the MultEQ-X app (download from the Microsoft Store. In-app purchase required), offering accurate room calibration and professional-grade precision INDIVIDUALLY CALIBRATED MICROPHONE - Each ACM1-X Audyssey calibration microphone is individually analyzed and assigned a unique calibration file tailored to each mic, ensuring measurements that can be corrected to match "Type 1" reference microphones OMNIDIRECTIONAL MICROPHONE FOR PRECISE SOUND MEASUREMENT - Equivalent to the ACM1HB Audyssey microphone included in popular AVR models, the ACM1-X captures sound from all directions, delivering accurate measurements for room acoustics correction NEW APP BASED APPROACH FOR ROOM EQ - Audyssey MultEQ-X lets you fine-tune both new and existing AVRs with MultEQ technology, providing enhanced control over calibration settings and detailed acoustic insights for superior audio experiences