What is Audio Engineering and What do Audio Engineers do?

Audio engineers are professionals responsible for polishing audio and managing the technical aspects of sound production. Engineering comprises various tasks and can be divided into three categories: recording, mixing, and mastering. Although many choose to work in the music industry, their skills are needed in various fields that deal with sound, including film, TV, or advertising.

Audio engineering is frequently used as a synonym for mixing and mastering, but the work of many industry professionals starts with recording audio in various contexts. Engineers are essentially responsible for managing the recording process from start to finish. They are expected to create an ideal environment that allows live sound to be captured in a high-quality way, choose and set up the right equipment, distribute suitable microphones across a room, route signals through mixing consoles, and keep track of the sound balance during a recording.

The profession requires organizational skills, a good understanding of how sound behaves in different environments, and a profound knowledge of sound equipment. Moreover, engineers need good expectation management skills to communicate potential limitations and improvements with their clients. They also need to be aware of genre differences in engineering. For instance, the approach to recording, mixing, and mastering classical music differs a lot from other genres. Knowing of such differences can help engineers assess whether they have enough experience to provide clients with the high-quality recording they are looking for.

After finalizing the recording process, all individually recorded audio files are forwarded to a mixing engineer, whose tasks we will discuss next.

Audio mixing is a complex process that considers each individual audio track and its relationship to all other tracks involved.

In the past, a lack of digital technology rendered mixing challenging, expensive, and less accessible. Over time, the development of new analog equipment allowed for faster processing and manipulation of audio. The digital revolution, which introduced easy-to-use and visually appealing virtual tools, simplified the mixing process tremendously. Today, mixing is usually done in complex, well-equipped studios. Engineers typically use analog and digital tools, with some working exclusively with virtual plugins.

Audio mixing comprises various elements that allow for clarity and balance without losing sight of the artistic vision. Such elements are commonly referred to as mixing practices.

Balancing determines the volume-level relationship between all sound elements. It enables some sounds to stand out and places others further in the background to ensure they do not clash and overwhelm the listener.

Panning refers to the distribution of sound across two (or more) channels and speakers. Stereo mixing places sound from left to right, while spatial audio mixing comprises further dimensions (up and down), rendering a mix more immersive and interactive.

EQing revolves around removing undesirable frequencies to avoid muddiness, resonance, and frequency buildups. Cutting out unnecessary frequencies of one sound leaves more room for those essential to another. Equalizers can also be used as effect tools to give sounds a filtered texture, reminiscent of sitting underwater or listening to them through a phone speaker.

Engineers then use various tools to control the dynamics and volume of individual audio tracks. Some of the most commonly used dynamics tools are compressors, limiters, and gating plugins. They use them to ensure each note remains at roughly the same level. However, they also need to ensure they do not render a track lifeless by overcompressing it.

To add further dimension to a mix, engineers use various effects tools and plugins. For instance, reverbs, delays, and echos allow them to adjust the sound to an actual or imagined room, such as a church, tunnel, or studio. They also give a mix more character.

Where one chooses to start is usually a personal preference – while some prefer to begin with EQing to eliminate all nasty and unnecessary frequencies, others like to set the tone by balancing all elements first and then diving into all other aspects.

With that being said, the mixing process is rarely linear, requiring engineers to reconsider their decisions multiple times. This is because one adjustment can inadvertently influence another. For example, cutting out all low-end frequencies can make an instrument seem quieter. As a result, an engineer may have to once again readjust the volume.

Want to learn how to mix? Our article on the best music courses for producers and audio engineers may be a good start!

Once all tracks are adjusted individually and in relation to each other, a mastering engineer steps in. Working with the mixed stereo file, their job is to enhance the overall sound of a track or recording and prepare it for distribution. Among the most common mastering tools are compressors, (brick wall) limiters, metering tools, and stereo wideners. While some choose to use each tool individually, others prefer to work with a mastering suite.

Mastering engineers must know how to adjust the track to various mediums, including streaming platforms, CDs, vinyl, or broadcasting. If working on an album, they are required to create consistency across the entire project by ensuring all songs have the same loudness. Additionally, they are responsible for assembling the project by putting all tracks in the correct order and, if desired, blending one into another. The last step involves exporting all audio files, adding the titles, and including all necessary metadata.

It is important to note that the mastering process revolves around the final sound quality and that an excellent final product requires a high-quality mix. If the mastering process comes with one complication after another, engineers should return to the previous step and ‘fix it in the mix.’ Additionally, mixing and mastering engineers usually use different devices and rooms to monitor the audio quality. A track that sounds good in the studio may sound muddy in the car, requiring further adjustments.