System and Signal Flow

How do you make a smoothie?

You take a drink and some fruit, put it in a blender, and you get a smoothie!

A system is made up of 3 parts:

Input -> Process -> Output

To make a smoothie:

• the Inputs are the fruit and drink
• the Process is the blender, which blends everything together,
• and the Output is the Smoothie.

Let’s apply this to Sound, Visuals and Streaming.

A sound system is used to amplify sound (make it louder).

• Input devices: Mics, Instruments, Computers
• Process devices: Mixer, Amplifier
• Output devices: Speakers

We have a visuals and stream system to help people see lyrics, slides and what’s going on.

• Input: ProPresenter Mac, Cameras
• Process: Video Switcher
• Output: TVs, YouTube

Why is this helpful?

Knowing the signal flow through the system helps you work out how to troubleshoot the system.

For example, the signal flow for a wired mic might be:

mic –> stagebox –> mixer

If you can’t hear the vocal mic, you can check in order that that each part of the signal flow is connected, and working as expected. So in this case, (assuming everything is already turned on), you’d check that:

• Are things plugged in?
  • mic -> cable
  • cable -> stagebox
  • stagebox -> mixer
• Do the different parts work?
  • Mic
  • cable
  • stagebox
  • mixer

Over time, you will learn more about the system you’re working with, which will have more ideas on how to fix things if something isn’t working.