Last week I dove into filters, and this week I will continue on that theme with equalizers. Equalizers seem to be one of the things beginners get hung up on, and one of the processing tools most useful for mixing.
At it’s core, an eq is a combination of various types of filters. We started with set-band eqs, with a programmed curve, resonance, and frequency band, and the only possible adjustment was gain. Since then audio engineers have made much advancement, and the world of digital has allowed us even more capability. The most common eq most people are familiar with in a daw is the parametric eq, in which there are multiple bands which can be set to any filter type, frequency, resonance, and a selection of slopes. We can use these simply as filters, cutting out unwanted frequencies, but we can also boost content we want to emphasize or a combination of techniques.
A question many people have when they start to work with eqs, especially parametric digital equalizers, is what do I boost, what do I cut, and by how much? The answer is, of course, it depends. The first, and most important thing to keep in mind is that eqing should always happen in the mix. This is important to ensure all elements of the track work together and sound awesome together. You could have the best kick sound in the world, but if it doesn’t gel with the rest of the mix, it doesn’t matter. So, with that in mind, I will run through a few tips for using equalizers.
Start by cutting the frequencies you don’t want in the sound, although some people will say you should not do this but instead choose samples without extraneous frequency content you do not want. I will engage with that argument in a later post.
After cutting, you can start to gently attenuate or boost parts of the sound you want to diminish or emphasize. Depending on the sound and what your ears tell you about how the sound works in the mix, you can use shelf filters, notch, or a band filter, or any appropriate combination. When boosting, be aware of how much gain you are adding to the sound. It is entirely possible you will start to clip the sound by boosting the volume over 0dB, and that will sound bad. If you still need to boost by so much, use the output gain on the filter, or use a utility after, to match the input and output gain. This is important, not only to prevent clipping but also to allow your ears and brain to make the right mixing choice. A louder sound will almost always sound better than a quieter sound, thus matching input and output volume is crucial in making accurate decisions about how an effect sounds and if it is necessary.
When using both an equalizer and a compressor on a track, it is best practice to locate the compressor after the eq. This is to ensure you are only compressing the heard sound, and the compressor is not attenuating the gain based on a louder frequency band which the equalizer is removing.
I will conclude this post by mentioning dynamic equalizers. Examples of such are the free tdr nova, and the excellent waves f6. A dynamic equalizer combines the filters of a parametric eq with the active gain attentuation of a compressor. Depending on what problem you are trying to solve, or what type of sound you wish to achieve, dynamic eqs can be incredibly useful. It allows you to boost or attenuate a frequency band, and then apply a compressor on just that band. The compressors range can often be inverted as well, to boost a frequency but only when it crosses a set gain threshold. These compressors can also be sidechained, to allow you to move one sound out of the way of another in a very precise manner. I wouldn’t necessarily use these on every track or even each project, but they are a useful tool to have and have some knowledge of how to use.
Check back in next week for some tips on creative sound design effects using filters and equalizers.