A Balancing Act
The main thing we want from Equalisation, or EQ, is to make things sound intelligible - we want everyone to clearly hear the words, and to be able to distinguish the rhythm and melody so that they can engage with and follow the songs. Here's how:
Nature's Way - If something sounds natural, it'll probably be intelligible. The first thing we should do is compare what's coming out of the speakers with the source (the singer or instrument) - do they sound similar? What sounds out of place? For example, there may be a strong hiss when the singer speaks, or the piano might sound 'tinny'.
For Better For Worse - Now that we've identified what we want to change, we need to find the frequency or frequencies which make it sound this way. How? By making it worse!
- First, chose a frequency control (like high-mid), set the Q to 10 (super narrow and pointy) and boost the gain.
- Second, slowly use the frequency knob to sweep up and down the spectrum until you find a frequency which makes the vocal/instrument sound worse in the same way. If the piano sounded tinny, it should now sound even more tinny.
- Finally, reduce the gain at that point and the offending sound should disappear. If it doesn't, you may have the wrong frequency, or there may be more than one adjustment to make.
Into the Void - Some instruments have similar frequency ranges which clash, for example, the hi-hats and an acoustic guitar or the kick drum and the bass guitar. We can help listeners differentiate between instruments by boosting or cutting different frequency areas. In the case of the guitar and hi-hats, we would cut the hi's on the guitar but keep the rest of the sound. In the case of the bass and kick, we could boost the very low end of the kick for more 'thump' and boost the low mid of the bass for more 'warmth'.