Audio mixing is the art form of optimizing and summing multitrack recordings into a final mono, stereo or surround sound product. During this process the separated tracks are adjusted and balanced in level, edited, and go through various processing such as equalization, compression, and timed based effects as needed. Once the final mix is completed it can be sent to a mastering engineer for fine-tuning and enhancement.
Mastering is an art form of audio post production. Mastering a song involves taking a final mix and putting the final touches on it by elevating certain sonic characteristics. This can involve adjusting levels, stereo enhancement, and discrete audio processing. The final product will be polished and has a clean sound that translates well across different formats and systems. Modern mastering also includes monitoring, and the implementation of LUF recommendations and embedding metadata into files.