Audio Recording with Equalizers – 10 Equalizer Modes – Part Eleven – Graphic or Parametric EQThe final Equalization modes that I would like to discuss are Graphic and Parametric EQ's. These are two different modes, but since they are the two primary choices of EQ design that the user will choose between, I wish to close in a combined discussion on these modes. There are other EQ's, like Paragraphic among others, but Graphic EQ and Parametric EQ are the two predominant operation modes. You can technically design an analog Graphic EQ and Parametric EQ using the same basic signal path, and therefore with the same sonic integrity and character. However, they provide a noticeably different range of possibilities.
The Graphic EQ is defined by having multiple fixed Frequencies, each with their individual Gain, all available at the same time. We see these everywhere from live sound installations to car stereos and home stereos. Because the Graphic EQ is used so commonly in many scenarios outside of the studio, some people make the mistake of thinking that it is not meant to be used in the studio at all. In some ways, we truly tend to under-use the Graphic EQ. It is largely because the Parametric EQ was such a radical invention at the time it was developed, that it become the norm in most EQ designs. For the Console EQ, Parametric makes perfect sense, because the user can be provided a lot of flexibility in a small linear space, where a Graphic EQ on every channel would take a lot more space. For Outboard Equalizers, we often see the Graphic EQ being used to control the balance of the outputs in a given room, to EQ the speakers themselves, or for monitoring in multiple scenarios. Many live mix Consoles will have a Graphic EQ on the main output, which perpetuates the belief that Graphic EQ is not used in typical tracking, mixing, or mastering.
The reality is that the best sounding Graphic EQ's can be an incredible mixing tool, and although they are almost never used as such, they can be incredible for Mastering as well. In general the Graphic EQ tends to provide each EQ Band at the same precise width, with one Band backed up to the next. Since each band controls its own independent EQ with the same amount of boost and cut Gain, you can sculpt the entire output spectrum with individual control. With a Parametric EQ, you have various individual modes that help shape the output and the Band EQ's can be used in a flexible manner that we will not find in a Graphic EQ, but in the case of the Graphic EQ, we can add and subtract exactly the amount that we wish to for each part of the Spectrum needed. This can work wonders on individual tracks and on the main outputs. The Parametric EQ was originally designed for hand-built mixing consoles that became the world famous GML and Sontec lines of mix and master EQ's.
The Parametric design is believed to originate with these developers. The Parametric EQ was the first design that allowed the user to tune in on the exact Frequency desired, adjust the “Q”, and even select multiple bands for specific tasks, some of which could even overlap other bands. Since the Frequency, width, and Gain are all adjustable, the user can fine tune their EQ needs with a great measure of flexibility. Because we have become so accustomed to having the Parametric design for many years, it is hard to imagine not having this flexibility available to us. In analog form, the Parametric EQ provides us the structure, and the construction of the individual brand of EQ provides the individualized sound character.
Inside the computer, we are presented an increase in visualization options for the Parametric Equalizer, showing the movement of Frequencies, the width options, and allowing us to grab, bend, and stretch positions while seeing the shape on the screen. The Graphic EQ tends to exist in the digital realm as an emulation of the analog device, usually only adding the flexibility of input and output levels and volume visualization. I highly recommend exploring the EQ options in different formats, and always let your ear lead the way. Functionality is crucial, but sound quality is always the ultimate aim.