Mixing

The Mixing Process

Mixing is the process of fitting individual instruments together into a well-balanced song.

The goal is to create a coherent performance that reflects the original intent of the artist. Mixing involves several components.

i. Quality Control

The mixing engineer reviews the track for inconsistencies or artifacts that negatively impact the quality of the recording. These may include a noisy background, poor tonal quality, or occasional clicks or pops. If a problem can't be fixed in the mix, the engineer may recommend re-recording a track or section.

ii. Bussing

Related tracks are grouped for common processing. For example, the percussion elements may be grouped into a 'Drum Buss' to share the same spatial character.

iii. Track/Buss Processing

Each track and buss is processed to fit alongside the other instruments. Dynamics and tone are adjusted to give each instrument its own distinctive sound.

Instruments are equalized and compressed as appropriate to the musical genre. For example, in dance music, the drums are typically highly compressed with strong sub-bass characteristics. By contrast, a folk song only needs light compression and peak limiting to retain an open, natural sound.

iv. Track mixing

To produce a final stereo mix, multiple tracks in each buss are blended to create a well-balanced group. The different busses are then mixed together into a complete song. The dynamics and equalization of tracks and buses are adjusted until no instruments 'compete' in the same frequency range or on the soundstage.

Final mixes are usually given sufficient headroom (e.g. around -14 LUFS) and with reasonable peaks (between -6 and -1 dB TPM), so that the mastering process that follows has plenty of scope to tune the dynamics. Otherwise, if a final mix is later judged to be too compressed, the mastering engineer will be hard-pressed to 'de-compress' it.

In other words, the final mix should be clear, open, and tonally complete, but not necessarily radio-ready. It should be already close, but the mastering engineer's job will be to ensure that the track translates well on all systems: earbuds, car stereos, headphones, home stereos, and restaurant/club PAs.