Lesson 8

How Sound Waves Interact

Sound waves in air behave much the same as waves in water. When a crest meets a crest, they are summed together to make a crest of higher amplitude. When a crest meets a trough, they are summed together to cancel each other out. It’s a simple mathematical equation that when 2 waves meet, the position of each wave at the intersecting point is summed with the other, and a new wave is formed. 
When 2 identical waves meet, if they are in phase, the amplitude will double (+6dB), and if they are 180 degrees out of phase, they will cancel each other out, resulting in no sound at all. If they are out of phase by any value other than 180 degrees, the newly formed wave will be a different sound. 

In the video, do some examples of summing 2 waves in Logic. Show diagrams of of the 2 waves being summed, and also the sound. Excitement with different delays, and slightly offset frequencies, and tuning a guitar(wah wah effect)