The “Q” is how wide or narrow the cut of the EQ is. The bigger the number ( say, a Q of 4 or 10 or whatever) the more narrow the cut is, and more precise. The smaller the number ( like say, 1 or .5 etc) the more wide the cut or boost is. When you boost or cut a frequency you have selected on the parametric eq, you aren’t just boosting or cutting that specific frequency, you are boosting and cutting tons of frequencies around that particular point. Different eq’s have different curves therefore they have different tonality. This is the basics.
All cool right? It is, but it can be tricky, and you can easily run into phase problems when using an eq like this, but don’t worry about that too much right now. What IS important to remember is, generally the wider the Q, the more transparent the cut or boost will be. This is my preference, as it sounds more natural this way and less colored or noticeable that something is EQ’d. Narrow the Q as small as it can go ( probably 4 or so on that guy) and sweep through the frequencies until you find a resonancd you find particularly annoying… BE CAREFUL. It’s very easy to get crazy with this and start cutting everything and neutering the tone. It’ll get easier over time what to listen for though. Look for problems in the 3-500 hz area, and around 3-4K to start with. When you find something you don’t like, widen the Q back out to around 1, and start with a very small cut or boost, around 1db. It’ll make a big difference. This will keep it more transparent. Cutting stuff with a narrow Q is necessary sometimes for sure, but it’s easy to get carried away and often sounds less natural. Those kinds of problems can often be fixed at the source as well ( mic placement, mic, cabinet etc) But again, be careful around 3-4K, a lot of your pick attack and tone lives here.
This is the basics of a parametric. Again, I like using wider Q’s for boosts and cuts, it just sounds better to me.