Understanding the Basics of Analog Signal Flow & How They Relate to DAW Usage
Whether you’re just starting out with audio or an experienced practitioner, some principles are absolute. We may bicker over best practices for microphone placement or the nuances of tube vs. solid state. However, as with everything audio, it’s the fundamentals that are most important. As an educator, I find that one of the most critically important concepts to grasp is that of the signal chain. As we know, our consoles large and small can readily be dissected into parts of various sizes which makes the physical realm very easy to grasp for most individuals. However, signal flow comes in may shapes an sizes! After all, most students arrive at college today having experienced at least some DAW, meaning they have experimented with signal flow without being introduced to the theory. So, let’s take a really brief look at analog console signal flow and how it relates to the DAWs we use. You may be surprised how much more sense your software makes once you understand its analog brethren.
We begin by taking a look at the typical analog signal chain, laid out by David Miles Huber in his newest version of Modern Recording Techniques, 8th Ed. In a traditional hardware mixer (which also goes by the name of board, desk or console) design, the signal flow for each input travels vertically down a plug-in strip known as an I/ O module (See Example) in a manner that generally flows:
-From the input section
-Through a sends section (which taps off to external processing/ monitoring devices)
-Into an equalizer (and other processing functions, such as dynamics)
-Passing through a monitor mix section (which taps off to external monitoring devices)
-To an output fader that includes pan positioning
-Into a routing section that can send signal to selected mix/ signal destinations.
Figure Above: General anatomy of an input strip on the Onyx 4-bus analog mixing console. (Courtesy of Loud Technologies, Inc.)
How does all this relate to your DAW? Just as audio flows top-down through the channel strip of an analog mixer, so too does it flow through the virtual mixer of your DAW! What makes this more complex to grasp is that DAWs don’t follow a complete top-down visual flow which can be confusing, not to mention the fact that each individual DAW has a tendency to adopt their own visual representation of the analog.
Figures Above: The virtual mixer strip layout for (L) Pro Tools and the input strip for (R) Reason’s Mixer. (Courtesy Avid Technology, Inc., and Propellerhead Software)
As you look over the parts of your virtual mixer (several examples above), you should notice that the similarities between the analog and digital are striking. What you should remember is that input path selectors which visually reside at the midpoint of most virtual mixers actually feed the top of each channel strip just like a mixer preamp. Similarly, those output selectors function just like the output assigns on an analog mixer and are directing the overall channel strip output. Thus, you have only your channel signal flow left to worry about. Remember that inserts allow you to add not only EQ like an analog mixer but a host of additional effects to your DAW, and your sends still function as aux sends.
Why is this explanation important? If you’re diving right into digital, you may be surprised by how one change can radically affect your entire session but not understand why. It’s important to understand that signal flow still plays a crucial role in all our mixes, even if they’re taking place in-the-box. For more signal flow basics, be sure to check out David’s in his newest version of Modern Recording Techniques, 8th Ed and stay tuned for more upcoming posts on AudioUndone.com!
Opening image from Flickr user chrisbartelsmusic.
About the Author
Kyle P. Snyder is an educator, engineer, and consultant natively hailing from Northeast Ohio; he’s proud be a member of the Ohio University faculty as a Visiting Assistant Professor. An alumnus of Indiana University and Ball State University, Snyder holds a Masters of Science in Music Technology from Indiana University and a Baccalaureate Degree with specific emphasis in both Digital Media and English from Ball State University.
His research interests include pedagogical approaches relevant to the field of audio engineering and specifically how best audio students learn. Snyder frequently contributes to various industry publications and is widely published, a complete listing can be found on his website and in his curriculum vitae.
As an engineer and consultant, Snyder is routinely called upon by clients of local, national, and international acclaim including countless independent artists and ensembles, private companies, and academic institutions.
Professionally, Snyder is active in numerous organizations, including the Audio Engineering Society for which he serves as a member of the Education Committee and recently hosted the Second Annual Central Indiana Audio Student Workshop in the Spring of 2013. He is also the Faculty Advisor for the Ohio University Student Section of the Audio Engineering Society. Additionally, Snyder is a member of The National Academy of Recording Arts & Sciences, The Society of Professional Audio Recording Services, The Association for the Study of the Art of Record Production, and the Music & Entertainment Industry Educators Association.