Do you want your sound team to have absolute confidence in operating the console? Well, their understanding of the signal flow logic of the console is the key to that confidence because it is the most efficient way to clarify how the controls on a console interact.

The controls on most consoles are arranged in a way that provides an efficient system of operating the console. For example, controls that you would "set and forget" are placed at the top of the input strip, well out of your reach (e.g., the Mic Trim). Controls that you want frequent access to are placed right at your fingertips, like the Channel Faders. Figure 1 shows a typical arrangement of those controls.

The arrangement of the controls in this signal flow diagram (Figure 2) is fairly common. When we plug in a mic at the mic input, the first component that the signal sees is the input transformer. The strength of that mic signal is quite low, and needs to be increased in order to maintain a quiet signal-to-noise ratio throughout the console. That gain increase is accomplished with the Mic Preamp. A related control called the Mic Trim allows you to adjust for differing signal strengths at each channel, which then allows you to operate the faders in their optimum range.

The main path of the signal goes next to the Equalizer (EQ) section of the channel. Equalization is used to improve the tonal quality of a particular voice or instrument.

The signal then flows on to the Channel Fader. The fader is the best place to make adjustments in the balance of each voice or instrument during a song or drama sketch. Your mix will be smoother and quieter if you operate the needed channel faders in the upper one-third of their travel.

Now you'll find our signal path at the summing point. This signal flow diagram shows just one channel of the console, but let's say that it's a sixteen channel console. Each channel is identical up to here, and then the signal from all channels combine at this point.

The signal then goes to the Master Fader where you control the overall level of all the signals with one fader. Finally, the signal goes through the output stage of the console, and then to a connector on the back of the console where we feed the signal out to the input of our power amplifier.

That's the main path through any console. Now, look back at the signal flow diagram and note that right after the mic preamp and before the EQ there is a pickoff point. The path drops down to a control labeled Auxiliary #1, and then connects to the Aux #1 Buss. The "buss" is just a piece of wire that runs from one side of the console to the other. The signal then flows to the right to the Aux #1 master control, which controls the overall level of all the signals fed from the Aux #1 Buss.

Remember, our purpose here is to see how these controls interact, so imagine for a moment that you're adjusting the lead vocal mic on Channel 5, and Aux #1 is the vocal monitor mix. If you make an adjustment to the EQ on Channel 5, would that change be heard in the vocalist's monitor mix? No, because the feed for the monitor mix is picked off before the EQ. If you make an adjustment to the lead vocal fader, would that change be heard in the vocal monitors? No. We're using what is known as a "prefade" auxiliary send, since the signal is picked off before the fader.

Just past the fader is another pickoff point that goes to a control labeled Auxiliary #2. As before, it feeds the Aux #2 Buss. This time, imagine that the Aux #2 output on the back of the console is fed to the input of a reverb unit, and the output of that reverb device returns to the console. We adjust the send on Aux #2 of Channel 5 to add a reverb effect to the vocal. Now if you make an adjustment to the lead vocal fader, does that affect the signal going to your reverb device? Yes. Does adjusting the Master Fader affect the feed to the reverb device? No, because the feed to Aux #2 is picked off before the Master Fader. The Aux #2 send described here is commonly called a "postfade" send.

Understanding signal flow logic really is the key to maximizing the operation of your console. So here's a challenge for you. Study the signal flow diagram in the owner's manual for the console you work with. If their block diagram is awkward to read, redraw it so it looks more like the drawing in this article. Get to the point that you can take out a blank sheet of paper and draw the signal flow of your console from memory. I promise you, from that day on you will operate your console with confidence. Your mix will be consistent from week to week. Then the Holy Spirit can work through you. I found out long ago that the times I allow God to mix are the best. He mixes way better than I do! You'll notice a problem with feedback and your hand will dart to the appropriate knob to resolve the problem, and you won't even know why. This is way cool. So dig into the signal flow of your console, and then praise His Name with technical excellence.

NOTE: The previous section on signal flow logic was shortened to protect the weary and/or innocent. If you would prefer to read the original, unedited and longer version, please see the article in this website titled Maximizing Your Console.