On the one hand, the equalizer is a particular instance of a filter. On the other hand, filters can have slightly different parameters, so they belong to a different category of processing.
There are two types of equalizers: graphic and parametric.
Nowadays graphic equalizers can be usually found in expensive cheap mixing and mastering services. They are also used during concert activity, when a multiband tuning of the audio chain is necessary. The simplest example of such a device is a panel with a set of sliders, each of which either increases or decreases the sound amplitude on a particular frequency.
Graphic equalizers have certain advantages. The main one is their simplicity and the possibility to simultaneously change completely different portions of spectrum in both directions. The usability and good visualization in graphic equalizers also make them useful. However, the drawbacks of these devices are substantial as well.
The main problem is the inability to precisely localize the frequency that needs to be affected. This disadvantage becomes even more significant due to an increasing demand for high quality. If a resonance appears on the frequency of 1.7 kHz, mixing engineer will have to adjust the nearest slider, which will be responsible for 1.6 kHz frequency. Of course, it’s an extremely rough tuning.
The second drawback is that the quality factor level is hard-set for every band (we’ll talk about the quality factor a little later). Some expensive models have an option of adjusting the quality factor, but most of the equalizers seen in mixing studios lack this function.
If you need help with polishing your music please check our professional music mixing prices per song.