The linear frequency response and omnidirectional polar pattern of the Apex220 allows you to carry out measurement and alignment tasks with ease and precision. It is the ideal measurement microphone for use with any real-time analyzer or other audio test equipment. The Apex220's rugged construction ensures years of reliability.Note: A linear measurement microphone is, by design, meant to have a very flat frequency response and may not yield the best results when used as an audio source microphone for live or recording applications.