When equalizing a sound, the volume of the different frequencies is modified.
Equalize is a verb that comes from the English expression to equalize , translatable as “equalize.” The action of equalizing consists of modifying the reproduction frequencies of the sound or another type of signal, always within the framework of certain values.
The system that allows equalization is known as an equalizer . It may be a physical device ( hardware ) or a computer program ( software ) that serves to cut or boost frequencies, with which the tone and character of the sound changes.
Understanding the sound
Sound is a sensation that occurs in the ear. This is also the name given to mechanical vibration that propagates through air or other elastic medium.
Physics indicates that sound is transmitted through sound waves , originated from the vibration of a body. These sound waves are transformed into mechanical waves in the ear and are then processed and interpreted by the brain.
It is worth mentioning that the ear of a human being is capable of capturing sounds between approximately 20 and 20,000 hertz . Hertz measures the frequency of waves, with bass sounds being those of low frequency and treble sounds being those of high frequency.
What is equalization
By equalizing, you can regulate the volume of the various frequencies of a sound wave, thus changing the characteristics of the sound. Equalizers work with filters that alter the parameters in question.
It is important to note that when a sound is equalized, no new frequencies are produced or added. What is done is to cut or amplify the existing ones.
In a recording studio it is common to use equalization.
Filter operation
To equalize a sound recording, as we indicated above, filters can be applied. There are filters that cut the low frequencies to allow only the high frequencies to pass through and others that do just the opposite.
The so-called band-pass filter , meanwhile, supports the passage of a specific range of frequencies and attenuates the others.
Advantages of equalizing
Equalizing is an essential activity in any recording studio. The process can also be carried out at home with free software and without extensive technical knowledge, although logically without obtaining professional quality results.
Suppose a journalist records an interview on the street. The reporter can equalize the sound file to minimize the frequencies linked to ambient noise and, in turn, highlight those that are associated with the interviewee's voice .
Typically, it is decided to equalize to remove unwanted frequencies from the record . In this way the signal is “cleaned” to optimize the perceived sound. This corrective equalization is usually complemented by additive or creative equalization, which consists of equalizing to highlight certain frequencies.
Define the problem to solve
Although equalizing seeks to improve the sound, the objective is not always met. Sometimes, modifying frequencies does not produce the desired effect.
According to specialists, the first step to successful equalization is to establish which defect is intended to be corrected. There is no point in altering frequencies if you don't know what you want to achieve.
Excess and absence of low or high frequencies, for example, are not good. The idea is that the balance of the frequencies is appropriate.