Mixed Signals - a guided tour of mixer topography and signal flow

By Barry Cleveland

Mixed Signals
Our Guided Tour of Mixer Topography Helps You Go With the Signal Flow

Mixers are about signal flow. A good recording mixer lets you route a variety of input signals wherever you’d like and combine them into a stereo, mono, or even surround mix.

Audio travels through a mixer on a signal path. However, signal paths is more accurate because a signal is often sent to multiple destinations simultaneously, and sometimes a signal leaves the mixer and comes back in again. In analog mixers, audio signals travel through wires and circuits and are routed to various physical modules along the way. In digital mixers, the audio signals are converted to digital information at the inputs, and software does all of the routing and processing. (Of course, you can also route already-digitized audio in and out of most digital mixers.) Audio signals never make it past the converters, much less down any wires (see the sidebar “Digital Differences”).

Signals can flow in and out of physical components via actual wires (analog mixing), or a CPU can process a stream of zeroes and ones (digital mixing). Regardless, analog and digital mixers perform many of the same functions, and their user interfaces share many characteristics. For clarity I’ll speak mostly of analog signals moving from one point to another along physical paths. Just bear in mind that the basic concepts also apply to digital mixers.

Although all recording mixers handle more or less the same tasks, none of them do it in exactly the same way. Manufacturers offer a variety of routing options and special features, and they even name controls differently, so generalizing is sometimes difficult. There will always be more than one way to accomplish the simplest task—a prescription for confusion. I’ll look at the most common paths that signals take through mixers and briefly mention appropriate alternatives.

To keep things relatively simple, I’ll avoid issues pertaining only to large production consoles costing tens of thousands of dollars. Instead, I’ll focus on the mixers commonly found in personal studios. Though I won’t talk about any mixer in detail, I’ll use the Mackie 24/8 8-bus analog mixer and the Yamaha 02R digital mixer as examples. As two of the most widely used mixers on the market, they arguably represent the upper end of personal-studio mixers. That said, most of the principles I’ll discuss also apply to larger and smaller mixers.

I’ll take you along the signal path from one end of a hypothetical mixer to the other, stopping at major destinations along the way. But first, let’s talk channels and buses.

NEXT