Professional music mastering or post production is an important final technological process in the production of a commercially successful high quality audio product. Several operations, performed by a sound engineer, for processing the combined track ensure high quality sound in accordance with the world standards and full sound reproduction. As a rule, professional music mastering includes, if necessary, elimination of obvious defects, inconsistencies and misalignment of tracks recorded not only at separate time intervals, but also in different recording studios. The direct processing of sound is composed of dynamic and timbre correction, harmonic signal saturation, stereo correction if necessary, and the adjustment of all soundtracks taking into account the required sound volume and frequency spectrum according to the specific stylistic direction of music. Such professional audio processing with properly performed mastering can lead to a stunning high quality track that sounds just great. At the final stage of mastering, the track fade-in and fade-out (necessary ascent and descent of sound at the beginning and at the end of tracks) and quality editing of the album in accordance with the Red Book CD standard for CD replication are conducted. Also, the final preparation of tracks in the audio formats required by the customer for further replicating and transferring them to certain audio carriers is carried out.