EQ: Understanding Sound

I will be doing a series of post on the general use of equalizers for live music, but for this post I wanted to just go over the very basics of sound. Knowing this information will later aid you in fully understanding the concept of equalization.

How is sound made? Simply put, vibrations in the air. The rate at which the vibrations happen is called frequency. High-frequency vibrations produce high pitches and low-frequency vibrations produce low pitches. Frequency is measured in vibrations, or known as cycles per second. These cycles per second are called Hertz (Hz). You will notice knobs on mixers, EQs, and other equipment with a number followed by ‘Hz’ – Hz stands for hertz. (Ex. 80 Hz = 80 Hertz, 1kHz = 1,000 Hz)

Now that you know about frequency, it is important to realize that sounds you hear are not just one frequency. When someone plays a note on a guitar or a piano, you will get a fundamental frequency, but you will also get some higher frequencies, known as overtones or harmonics. The fundamental frequency is the note that you recognize. The overtones make up the tone color of the notes source, or timbre. The timbre is what makes a piano sound like a piano, a trumpet sound like a trumpet, and a violin sound like a violin. When they all play the same note together, their timbre allows you to pick out the different instruments.

All frequencies make up what is called the frequency spectrum and the part of the spectrum that we can hear is called the audio spectrum. The audio spectrum is from about 20Hz to 20kHz and any portion of the frequency spectrum is known as a band. It may be a wide like the range of synthesizers or it may be narrow like the human voice. Bandwidth is how narrow or wide (measured in Hz) the band is.

This is just a basic overview of how sound is made and a couple of terms that are very useful to know. Keep checking back for more information on equalizing live sound. I will quickly go over some of the new words you learned today. 😉

Frequency is the sound vibrations related to what we hear as pitch. Higher-frequency vibrations produce high pitches and low-frequency vibrations produces low pitches.

Hertz (Hz) is a unit of frequency. Simply, the number of vibrations per second.

Fundamental Frequency is the actual pitch that you recognize.

Overtones make up the tone color, or timbre, of an instrument.

Timbre (pronounced TAM-bur) is the term for an instruments tonal characteristics. It is what makes the piano sound like a piano and a trumpet sound like a trumpet.

Frequency Spectrum is a spectrum of frequencies.

Audio Spectrum is the spectrum of frequencies that are audible by the human ear. (About 20Hz – 20kHz)

A Band is a portion of frequencies. Ex. The human voice has a band of approx 80 to 1200Hz.

Bandwidth is how wide or narrow (measured in Hz) a particular band is.


0 Responses to “EQ: Understanding Sound”

  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Seismic Audio

Enter your email address to subscribe to this blog.

Join 2 other followers



%d bloggers like this: