The Foundations of Mixing (What, Why, and How)
1. What is Mixing? (The Definition)
Mixing is the process of combining and blending individual track elements (such as vocals, instruments, and drums) to create a cohesive and balanced piece of recorded music. It occurs after the recording stage and before the final stage of mastering.
A simple technical definition states that mixing is where multitrack material is refined and finalized for tonal balance, dynamic consistency, and optimised for playback across various platforms. Less technically, mixing is described as a sonic presentation of emotions, creative ideas, and performance.
2. The Mixer’s Role and Philosophy
Mixing is often wrongly assumed to be a purely technical service, but it is fundamentally an art. The goal of mixing is simple: to blend the individual tracks in a way that creates a polished, unified, and pleasing auditory experience for the intended listener.
The fundamental principle that all great mixers must follow is to serve the song. The technical skill of the engineer should always serve the creative vision, not the other way around. A mix is only as good as the song itself.
3. The Core Elements (The Holy Quad)
To achieve a finished mix, you manipulate four key areas, often referred to as the “Holy Quad”:
| Element | Tool | Function |
|---|---|---|
| Volume | Fader | The most important and foundational element, adjusting the overall loudness of each track. |
| Equalization (EQ) | Equalizer | Manipulates the tone of instruments by raising or lowering the volume/gain within different, specific frequency ranges. |
| Dynamics | Compressor, Limiter, Clipper | Controls the dynamic range (the difference between the loudest and quietest parts). A compressor is essentially an automatic gain reduction machine. |
| Space | Reverb, Delay, Panning | Gives music a sense of space, realism, or immersion. Panning controls the left-to-right placement of a sound. |
4. Frequency and Balance
The core objective of mixing is to achieve three types of balance: Tonal Balance (frequency), Dynamic Balance (volume/compression), and Spatial Balance (panning/reverb).
- Frequency Range: Sound travels through the air as vibrations. The rate at which sound vibrates is called frequency, measured in Hertz (Hz). The general range of human hearing is from approximately 20 Hz (the low end) up to 20,000 Hz (20 kHz) (the high end). Frequencies below 20 Hz are known as infrasound, and those above 20 kHz are ultrasound.
- The Foundation of Volume: Volume balance alone accounts for approximately 80% of a great mix.
- The Auditory Trick: A fundamental issue in mixing is that our perception of frequency changes relative to the volume level we are listening at. This is described by the equal-loudness contours (such as the Fletcher-Munson Curves). This concept means that louder sounds are automatically perceived as better. This non-linear perception makes it critical to use proper gain staging to ensure you accurately hear what processing (like EQ) is doing without being fooled by the increase in loudness.
