The measurement mic if you're serious about sound. Accuracy, consistency, and reliability have made the Earthworks M30 measurement microphone the first choice of live sound professionals, acousticians, and researchers all over the world. Used on countless full-scale concert tours, as well as in scientific research laboratories, tropical rainforests, and rocket testing facilities, the M30 and its M-Series siblings have proven to be lab-grade audio instruments that can handle any environment. The M30 is a precision engineered 30kHz omnidirectional measurement microphone ideally suited for acoustical measurements including loudspeaker design and quality control, sound system setup and troubleshooting, room acoustics, or any application where an accurate free-field measurement microphone is required. The M30's audio performance is unparalleled. It has a flat frequency response that extends from 3Hz to 30kHz, an exceptionally consistent omnidirectional polar response, 140dB SPL rating without distortion and no handling noise. With temperature compensated electronics, the M30 was built to deliver repeatable results no matter what the environment. Extremely fast impulse response and linear phase response make the M30 ideal for use with high-quality FFT-based real-time audio system measurement software like SMAART™, SIM™, REW™, Electroacoustics Toolbox™, FuzzMeasure™ and others, as well as for use in PA system alignment and loudspeaker design. Every M30 is individually hand-tuned and tested and is delivered with its own printed frequency response chart. An Electronic Calibration File (ECF) is generated for each microphone during final testing, and can be downloaded free of charge after product registration.