Essentially they all have the same goal of attenuating or boosting a specific band of frequencies chosen by the user. They can appear in either hardware or software form too. As you can probably guess there are many different types – parametric, graphic, linear phase, passive and active. Whether you mix or master, operate live sound or configure PA systems, EQ is an absolute necessity to do your job. The process of tonal adjustment is mostly achieved using an EQ, something you’re probably familiar with already. EQ is possibly the most important tool in the box. You’ll be presented with an idea of where to start, and you’ll begin to clearly imagine the final sound of which you are trying to achieve when mastering your own, or other artist’s music. Throughout this chapter you will realise some of the very purposes of the mastering process. The next step is to explore the idea of shaping a track from a spectral point of view. The chapter ‘ What is Audio Mastering‘ should have given you a rough idea about what we are trying to achieve when mastering music.