
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.
