Written by Martin Guldberg – www.klangheim.com

Equalizers and Compressors – your two main tools

The two tools you may be using the most when you work with mixing or mastering audio is equlizers and compressors. If you are a beginner it is a good idea to get familiar with one or just a few plugins of each kind.

As with almost all plugins it is more important how you use them than what you use. However, there are different kinds of equlizers and compressors and before you pick your favorite ones to practice with you should get aquainted with some of the different types.


Graphic equalizers

Graphic equalizers have a number of sliders that represent a frequency range or band. You can boost or cut a certain frequency range by moving the relevant slider up or down. This type of equalizer is called graphic because once you have ajusted all sliders to your taste they resemble a graph of the equalizers response to the incoming audio. The SPL ”Free Ranger” plugin is an example of a good, free graphic equalizer.


The SPL Free Ranger Graphic Equalizer plugin


Parametric Equalizers

Parametric equalizers are multiband variable equalizers. In other words they normally allow you to control to some extend the frequency for each band as well as the bandwith and of course the amplitude (by increasing or decreasing the volume of the chosen frequency). Parametrtic equalizers allow you to make very precise ajustments to the audio signal you are working with and is the preferred type of equalizer for many audio engineers. An example of a good, free parametric equalizer is the ”MEqualizer” by MeldaProduction.


MEqualizer from MeldaProduction is a versatile and good free parametric equalizer plugin


Linear phase equalizers

Grapic or parametric equalizer can produce phase distortion since when you boost or cut a frequency the processing will cause a delay between the frequency areas you have affected with the equalizer and the rest of the frequency spectrum. We sometimes call this type of phase distortion ”smearing” and in many cases this can be a desired effect in mixing. After all the effect is also apparent in the famous vintage or analog equalizers that so many companys emulate in their software.

But when it comes to the mastering proces we would normally want to avoid phase distortion. That is where the linear phase equalizer is a helpful tool.

Linear phase equalizers do not have phase distortion. The signal of the unprocessed frequency bands are delayed so that they stay in phase with the processed frequency bands and thus phase distortion or smearing is avoided.

In the mastering process we may seek to work as transparently as possible and in such cases the linear phase equalizer is a valuable tool. The Voxengo ”Marvel GEQ” is an example of a good, free graphic linear phase equalizer.


Marvel GEQ is a free Graphic Linear Phase equalizer


For information about compressors check out this article: