The audio equalizer or EQ is designed to manipulation frequencies heard in any audio signal from music to telephones. There are many types of audio equalizers ranging from the simple treble and bass controls in your cars to the 25-30 band equalizers used in recording studios and live concerts. In this article we will focus on the uses as well as the ideas behind audio equalization.
The Job of the Audio Equalizer
The job of the audio equalizer is to attenuate or boost frequencies of an audio signal. This function is useful for many different purposes. If you’re an audio engineer creating a professional product or if you just want more bump in your car stereo most likely you have used some form of audio equalization. In the world of live and recorded music the audio equalizer is invaluable.
Every room or space has its own acoustic traits and in most cases there a need control sound within the room. For instance, if a room has an undefined “muddy” sound you will hear it in every instrument or signal played in that room. With an audio equalizer you have the ability to attenuate undesirable sounds such as room resonance by ‘cutting’ offending frequency range(s) of the auditory spectrum. Audio equalization is used in every aspect of sound production for crafting a signal into a desired sound.
There are many types of audio equalizers. Whether digital or analog, they all run on the same principle: taking an audio signal and change frequency response. My first experience with audio equalization came when working with less than desirable guitar amplifiers. Through experimentation I got a feel for using an equalizer, shaping sound by reducing lows sounds and/or adding body and shimmer with slight boosts at different frequencies.
Audio Equalizer Differences
Different equalizers allow different equalization techniques. Parametric equalizers are known for allowing adjustable bell curves that can cut or boost frequencies with a more natural sound due to the broad range of the signal it can affect. Another common curve is shelving, smoothly cutting out or turning down the low of high end of audible spectrum. Parametric equalizers or notch filters also allow for detailed control pin-pointing specific sections of the frequency spectrum to reduce feed back or peaking. Professional audio equalizers usually have a higher degree of control and an engineer may use all of these techniques simultaneously to achieve a sound suitable for the listening or recording environment.
From car stereos, guitar amps, telephones to recording studios, Audio Equalization is an essential tool. Starting out experiment with some settings and let your ears do the rest. Once you have an idea how different audio equalizers and there techniques affect sound you can begin to mastering the various techniques necessary to make your recordings or and productions sound their best.
