How Guitar Pedals Work

Okay then, let's look at how some of these great guitar pedals work.



Shown above are some basic "sinusoidal" shaped sound waves. Our ear detects these when music is played. Various "Guitar Pedals" or "Stomp Boxes" can be used to modify these basic sound waves to create new and interesting sounds.

The mathematics of sinusoidal shaped waves involves the trigonometry of right angled triangles. This is illustrated very nicely by the following diagram:
(Copyright Russell Kightley - www.rkm.com.au - used with permission)



Russell also has a brilliant animation of the sine wave being generated, as the radius of a circle is moved in a manner which continually alters the sine value of the angle. (it also cleverly illustrates Cosine at the same time).

Go to the following link to view this sine wave animation:
http://www.rkm.com.au/ANIMATIONS/animation-sine-wave.html

Russell also has many other amazing animations and images at his website:
http://www.rkm.com.au
(Check it out, especially the scientific drawings of influenza viruses).

In this post we will look at "Chorus" and "Distortion", and how the mathematics of wave re-shaping works for these two sound effects.

Chorus Effect

If we add in extra sound waves that are of similar shapes, all around the original sound wave, then we create the classic guitar “CHORUS” sound effect. This makes things sound like more than one guitar is playing and is often said to fill out and "color" the sound.

In the world of guitar effects chorus makes one guitar sound like multiple guitars playing the same thing in unison. Just as each singer in a chorus would have different voices that blend, a chorus effect for a guitar will sound like different guitars all playing together.

This is demonstrated in the two sound samples below.

Press the play button of the mini-player on each one to hear the guitar play, both with and without Chorus effect applied.

Distortion Effect

Distorted Heavy guitar sound occurs when smooth Sine Waves are mathematically transformed into Square shaped, Sawtooth, and Triangle shaped waves. This is shown in the animation below:



Basic Distortion effect is demonstrated in the two sound samples below.

Press the play button of the mini-player on each one to hear the guitar play, both with and without Distortion effect applied.

The sounds in this post were made using "Magix Music Maker 15".



Magix Music Maker is only about $50 AUD to buy on eBay and is a marvelous set of sound loops and song making software that is so nice and easy to use. We will be doing a full review of MM15 in an upcoming post.

But in the meantime, get into stomping on those pedals, and make a myriad of marvelous sounds with your guitar. I know that's what I'll be doing this week :)

Enjoy,
Big Passy Wasabi