Buses group tracks together (allowing for group processing) and auxes affect the duplicate signals of tracks (allowing for parallel processing). This gives you control over the mix between the dry (original track) and wet (aux track) signals. The benefit of using an aux track is that you can apply processing to a duplicate signal without affecting the original track's signal. The signal that gets sent to an aux track is a duplicate of the original. Aux (Return) TracksĪn auxiliary (aux) track accepts signal being sent to it from various different tracks the main thing that differentiates it from a regular track is that you can't record audio to it. It's where all of your track outputs merge together before leaving your DAW. The master channel in your DAW is also a bus and is commonly referred to as the master bus. Songs will typically have a drum bus, instrument bus, and vocal bus. Different instrument groups are often bussed and processed together to make them sound cohesive.

BusesĪ bus is a point in a signal flow where multiple channels are routed into the same output. They're all modelled after mixing consoles, so the way signal is routed through them is similar to how it's routed through a console. This holds true in all the DAWs that I've come across as well. To perform parallel processing, you have to send signal to an auxiliary (aux) track.