If you are an audio mixer, you probably have used buses, groups, submixes, and stems to organize and process your tracks. But do you know the differences and advantages of each method? In this article, we will explain what buses and groups are, how they differ from submixes and stems, and what are some common challenges or pitfalls of using them.
Buses and groups are two ways of routing multiple tracks to a single channel, where you can apply effects, volume adjustments, or automation. Buses are virtual connections that send the signal from one or more tracks to another track, without affecting the original tracks. Groups are physical connections that link the faders or knobs of several tracks, so that they move together. Buses and groups are useful for creating submixes, which are mixes of specific groups of tracks, such as drums, vocals, or guitars.
Buses and groups are both ways to combine portions of sounds. The MASTER fader, for example, controls the volume of the main group in your mix session. Buses can be thought of as running in "parallel" to the other tracks, where as groups can be thought of as a serial combination of tracks. Groups are typically used to hold a single master control for a submix. Buses can provide greater control, when applying different amounts of independent effects across many tracks. Submixes are rendered audio files containing combined audio tracks that have been recorded through buses and groups. Stems are submixes, but with 1 audio track per instrument or patch. Submixes are good for reducing CPU load when using effects, at the cost of flexibility.
Using buses and groups offers flexibility and efficiency but can lead to challenges. Common pitfalls include complex routing, which may confuse the mix, making it harder to troubleshoot. Automation can become cumbersome when applied to multiple tracks routed through buses. Also, processing applied to buses affects all tracks routed through them, potentially limiting track control. On the other hand, submixes and stems offer more control and clarity but can increase project complexity and CPU load. Managing numerous stems requires meticulous organization and can slow down workflow. Plus, bouncing stems prematurely can restrict future mix adjustments. Grasping these challenges helps in choosing the most suitable approach for each project.
Submixes and stems are two types of audio files that result from bouncing or exporting buses or groups. Submixes are stereo or mono files that contain the processed signal of a bus or group, without any master effects or automation. Stems are stereo or mono files that contain the processed signal of a bus or group, with the master effects and automation applied. Submixes and stems are useful for archiving, sharing, or remixing your projects.
Most labels require Stems for every song mixed. The most common are the following: - Drums - Bass - Guitars - Synths - Keys - Orchestration - Special FX - Lead Vocal DRY - Lead Vocal WET - Backing Vocals - Effects.
Buses and groups have several advantages for audio mixing. They can help you save CPU power, by applying effects to a single channel instead of multiple tracks. They can also help you create a balanced and coherent mix, by controlling the levels and dynamics of different elements. They can also help you add depth and width to your mix, by using panning, reverb, or delay effects. Finally, they can help you speed up your workflow, by making it easier to edit, mute, solo, or copy your tracks.
Special attention can be given to pre- and post-fader staging of buses. This means that buses can receive audio from tracks at any point in the signal chain, which allows for awesome techniques, like: custom delays, ad hoc phasers, and handmade doppler effects
Submixes and stems also have several advantages for audio mixing. They can help you preserve your mix decisions, by creating a backup of your processed tracks. They can also help you collaborate with other mixers, by sending them your submixes or stems, instead of your entire project. They can also help you adapt your mix to different formats or platforms, by adjusting the levels or EQ of your submixes or stems. Finally, they can help you create new versions or variations of your mix, by combining or replacing your submixes or stems.
Buses and groups are not without challenges or pitfalls. One of them is phase cancellation, which occurs when two or more tracks with similar frequencies are out of phase, resulting in a loss of volume or clarity. To avoid this, you should check the phase alignment of your tracks, and use phase inversion or delay plugins if needed. Another challenge is over-processing, which occurs when you apply too many effects or compression to a bus or group, resulting in a dull or distorted sound. To avoid this, you should use effects sparingly and tastefully, and use parallel processing or automation if needed.
Bandwith is another important issue. Care should be taken, as buses/sends and groups can quickly become distorted by too much volume information
Submixes and stems also have some challenges or pitfalls. One of them is file management, which involves naming, organizing, and storing your submixes or stems in a clear and consistent way. To avoid confusion, you should use descriptive and logical names, and create folders or categories for your submixes or stems. Another challenge is quality loss, which occurs when you bounce or export your submixes or stems at a lower bit depth or sample rate than your original tracks, resulting in a loss of resolution or fidelity. To avoid this, you should bounce or export your submixes or stems at the same or higher bit depth and sample rate as your original tracks.
Submixes can become cumbersome quickly. It's usually best to only use submixes in situations where a large number of tracks need to be effected as one group. There's nothing worse that having to bounce an entire session for the 100th time, to accommodate that .1 decible volume drop in the cowbell