When inserting audio effects across tracks and busses is as easy as moving a fader, should we care about the order in which they happen? We shift things around.
Signal flow is something that most engineers will be aware of, and understanding it is central to so many things that we do in our daily work. Before the DAW, signal flow was certainly more visceral in the hardware studio, where making and breaking connections was easy to understand when physically patching between destinations with leads. In the DAW era, signal flow is no less important when it comes to getting gear or plugins to behave as we expect, but the nature of in-the-box workflows can sometimes make it easy to forget its presence.
Signal Flow
From getting a signal into a system, through processing and mixing, and onto final delivery, everything that happens in a project happens in a certain order as decided by the engineer. This is signal flow, and with the ability to use multiple audio effects or processors in a project, this order is important in shaping the effect plugins or hardware have in a mix. There are both technical and creative reasons that can affect signal flow decisions.
Technical Vs Creative
There are certain cases where logic dictates the order of processors, for example, expansion/gating before compression or limiting. The former needs some dynamic range to work with, while the latter will reduce it, and working the other way around would make both processes less effective. On buses, as the final arbiter of loudness and clip protection, the limiter usually comes last after any compression or EQ.
Although some of the above factors are a consideration in creative processing, ultimately there are no rules when trying to achieve an aesthetic, and this is no more stark when it comes to using creative time-based effects on stage or in the studio. For example, taking a piano sound that has delay and chorus, there’s a choice to be made between adding delay tails to a chorused sound or chorusing to something and its delay tails. The results sound different to each other, and the reason is the order in which they happen.
Effect Order Matters
Knowing and understanding signal flow is key to knowing how your audio plugins or gear are going to behave before you even use them. As well as this, an awareness of it allows us to solve problems quicker and opens up a wider understanding of the studio environment in general. While the engineer must weigh up technical considerations with creative ones when using processors, time based effects present a different approach. Effect order matters because it can be used to change the way multiple instances interact with each other. Getting a handle on this as well as fishing for happy accidents is the best way to get the most out of your creations.