This is a complete Surround Kit with five carefully factory-matched . Even though the standard tolerances on the 4015s  are extremely low, the surround match is even closer. The specially selected 4015 Wide Cardioid Microphones are matched within ±1 dB on both frequency response and sensitivity from mean of set. Recording orchestras or other acoustic ensembles sometimes requires a compromise between blending in the room reverberation and a more precise localization. The natural response and dynamic range make this Surround Kit an obvious choice for precise tone quality and wide dynamic range. This is a great solution for AB, Decca Tree or surround main arrays like our Wide Cardioid Surround Array.