Application

Remember that equalization is a problem-solving procedure. This means that there's no point in playing around with the settings if you don’t know what you want to achieve and how the final result should sound. A good approach to equalization is to listen carefully to the soloed track and come up with a list of things you might want to improve or correct. If you are using a parametric EQ, the next step is to bring up the gain and sweep across the frequency range until you find the frequency range you want to cut or boost. After that, boost or cut as desired. 

Keep in mind that when equalizing you will have to make small adjustments every time you add tracks to the mix since the frequencies and respective ranges of the other instruments affect the way an instrument sounds. The most important concept here is to be able to emphasize the characteristic frequencies of the track you are working on and eliminate frequencies that do not enhance its sonic features in any particular way. In fact, you should be able to “carve” a small niche inside the audible range for each instrument and section so that it is clearly intelligible and not masked by other instruments. If the mix sounds muddy and cluttered you should start trying to focus on which instruments contribute to the clutter. Try to use the equalizer to add clarity by gently shifting the center of each instrument involved so that they do not overlap with each other. As a general rule it is always better to cut than to boost, mainly because the human ear is more used to a reduction than to an augmentation in intensity of frequencies.