Sound mixers are responsible for recording and managing sound for theatrical productions, films, and television shows. They will record the dialogue and sound effects for the production. They have major responsibilities both before and during production. After production, the sound files will generally be sent to someone else. Before filming, they will meet with directors to determine how they want it to sound, what the technical requirements are, and what the budget is like.
They will also meet with many other departments to decide where the microphones will be placed. They will go to all filming locations to determine if there will be any sound problems. During filming, sound mixers will determine which microphones need to be used. They must notify the director of any issues that they are having with the sound and ask for another take if necessary. They must make sure that the sound is absolutely perfect, so they must watch for distortion due to high levels, keep the levels consistent, and provide a soundtrack with perfect audio. Sound mixers are usually over a crew that has at least one boom operator and one cable person. They must make sure that there are no boom shadows present in the filming area.
Sound mixers usually do not have any educational requirements, but they generally do have some type of sound training. They will have worked in some capacity in the film or sound industry before becoming a mixer. They must be well-versed in acoustics and sound equipment.