5. Using EQ as a Troubleshooter Tool
Sometimes it happens that the sound you process doesn't meet your requirement at all. And then you start the "surgery": you use dozens of filters to cut out all the resonances and change the sound character. Eventually, you change the sound leaving nothing of the original signal, but the end result is unlikely to be satisfactory.
In most cases, if you see that the sound has lots of problems, it's worth replacing it with a different one. If, for example, you want the hi-hat to more distinctively cut through the mix, do not immediately start tweaking the EQ, try to change the pitch of the sound itself.
If you work on frequency conflicts, first check if the problem can be solved by better panning or changing the signal levels, and only then proceed with EQ-ing.
6. Using Only One EQ on a Track
Here we'll talk about compression a little bit. The compressor narrows the dynamic range of the signal which makes quiet parts sound louder and vice versa.
Now let's assume that when mixing we have equalized the sound that seemed to us too dark and unclear and added a few dB in the high mids. In the classical chain of effects, the equalizer goes before the compressor. But the compressor was tuned before the changes in the equalizer, that is, all the settings may no longer be applicable, because the very incoming signal has changed.
To avoid this error, use one EQ before the compressor and another one after it. The first one will be responsible for cutting out all unwanted resonances and frequencies, while the second one will be used to artistically build the sound timbre
7. Working With No Breaks
This paragraph may serve as a general recommendation for any working process, but, in the case of EQ-ing, it's even more important.
Our ears very easy get used to a bad sound. After hours of work, no matter how hard you try, you won't be able to objectively assess the sound of the mix or the track you process. The more often you give rest to your ears, the easier it will be for you to make the right decisions.
It doesn't mean you need to make breaks every 5 minutes, because you may easily lose the working mood. Just try to find the right balance between working and resting. We'd suggest to start with this schedule: make 10-minute breaks after every 50 minutes of work
8. Not Using Reference Tracks
Reference tracks are your excellent assistants throughout the entire musical production, from drafting the original idea to final mastering. Using them during the equalization is the part of the process.
For example, you might like your piano sounds, but the whole mix sounds muddy. If you listen to a reference track of a similar musical style with a similar set of instruments, you may notice that the piano there sounds great within the context of the entire mix, but it has much less high or low frequencies compared to your mix. Using this principle, you can one-by-one reassess your approach to any sound.
Reference tracks can be of a great assistance if you're pressed by time and don't have the opportunity to put your work on hold. In such situations listening to a commercial mix may bring your perception back to the norm. But, still we suggest you to afford making at least a couple of minutes breaks.
As usual, we advise you not to mechanically follow these recommendations, try each of them on your material. Anyway, we are sure these tips can be your starting point in such a difficult task like music mixing.