The equalization process is inevitable whether it be for optimizing the quality of an audio recording or for sound design. Other tools allow us to manipulate the timbre of a sound signal but equalizers are versatile devices (or software) for sculpting the spectral range of a sound and adapting it to its needs.
Originally used as a simple filter to attenuate high or low frequencies, equalizers in various categories now offer many sound processing options.

For example, parametric equalizers, in the form of plug-ins, can now operate in linear phase (which considerably reduces the impact on the signal phase), in M/S and even in a dynamic way.

The Pro-Q 3 plug-in equalizer from the Dutch company FabFilter offers all these options.

Other less versatile equalizers are still popular with sound engineers. Analog equalizers are distinguished by their specific components and electrical circuits that colour the sound with a unique, manufacturer-specific imprint.
Ex. : Pultec EQ
It also happens that these equalizers introduce, as a kind of added value, a pleasant and unique distortion giving a unique character to the timbral characteristics of the sound signal.
Ex. : Neve 1073 Channel Amplifier
Every good technician knows that, beyond the legendary aura that surrounds a specific equalizer model, what should motivate the selection of a sound processing tool is linked to the specific needs of the project :

  • Does the sound signal need to be manipulated in a precise and surgical way?
  • Would wider and more ambitious manoeuvres to modify the sound timbre be helpful to the musicality of the project?
  • Can we allow ourselves to act very freely on the phase and harmonic response of the sound signal?
  • Is the impact on the processing time (latency) of this equalizer (plug-in) negligible or problematic?

A single equalizer to handle all these tasks? Instead most technicians use different types of EQs to meet the challenge of the job.

Note: UAD plugins require external DSP cards to operate. If you want native alternatives of equivalent quality (that can be used in the classical way with a simple computer) you can turn to Plugin Alliance or IK Multimedia T-RackS also offering emulations of Pultec, Neve 1073…

Questions or comments about this article? Contact the author : Jonathan Doyon –

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