The most important equalization concept you need to know about is 'the less is the better'. It means that while recording an instrument or voice you shouldn't compromise on quality hoping to fix errors later on during post production. Due attention should be paid to the microphone's quality, its position against the sound source, room audio treatment, etc. We've talked about the latter in one of the previous articles
When all these rules are finally met and the recording is properly made, EQ will play only 'cosmetic' role of emphasizing more important frequencies and cutting out unnecessary parts of the sound spectrum.
There are two main types of multi-band equalizers: graphic and parametric. Graphic EQ's sound spectrum is split into a fixed number of frequency bands with unadjustable operating frequencies, bandwidths around them and gain ranges. Only the level of amplification/attenuation of the center frequencies is adjustable.
Parametric EQs have much greater capabilities and flexibility, thus we'll further focus on this type of EQs. At the end of the article we'll provide the list of virtual equalizers that are the best in our opinion.
Any EQ represents a combination of different types of filters where the most used ones are the following:
- Bell filter - a bell-shaped or haystack filter controlling a set of frequencies around a center frequency;
- High pass filter - a filter (sometimes called a Low cut) that drastically attenuates low frequencies below a certain cutoff frequency and allows frequencies above to pass;
- Low pass filter - a filter (sometimes called a High cut) that drastically attenuates high frequencies above a certain cutoff frequency and allows frequencies below to pass;
- High shelf filter- a filter enabling to attenuate or boost frequencies above a certain cutoff frequency;
- Low shelf filter - a filter enabling to attenuate or boost frequencies below a certain cutoff frequency;
- Notch filter - a filter enabling to attenuate frequencies in a very narrow band to very low levels, also known as band-rejection filter.