EQ stands for equalization.
I want to write about the two knobs that old school consumer electronics had. The treble and bass controls on radios and amplifiers. Do you know somebody who always turns them up? Changing all the sound coming out of his stereo to his or her preferences. But what are these preferences based on?

He or she
… has paid for these knobs and just has to use them.
This habit is actually lowering the mids. The poor mids don’t have a knob of their own, and by boosting their neighbors they get behind in the frequency balance of the undoubtedly preference based volume adjustment.

… claims to compensate lacking gear or room acoustics.
What about the car stereo – same problem? The old radio – same problem? Incidentally the same problem in all audio gear within reach of this person. Try speaker (re-)placement.

… got used to the sound long ago.
This is probably true, but turning the knobs up is covering the symptoms, it’s not the cure.

… finds it sounds more hi-fi
This comes from a youth spend with very old or very cheap radios, receivers, cassette-players or compact record-players. The veils went up when the first proper hi-fi entered the living room. Like blankets were removed from the speakers. It’s a nice metaphor. Unfortunately I can’t provide one about dwarved mids.

The mids. They are the core of music. Many musical pieces were written for solo instruments or small ensembles exploring the beautiful kindom of mids. There’s considerably less music written for glockenspiel, triangel or cymbals. Strange, considering how hi-fi that would sound. Simply put, these treble instruments are the icing on the cake of music, but not the cake itself. Also few solo pieces for double-bass or tympany are being performed regularly. They just don’t deliver the goods, the mids.

Melodies live in the kingdom of mids. And you also find the most beautiful and complex harmonies there. You don’t hear a jazz chord with a root above 10khz. Or below 60hz. So by boosting these cake-icing frequencies you get less cake. Which you paid for too! Not only in your stereo gear, but the music itself as well. A professionally mastered recording is sounding good on neutral speakers. A serious test in the life of a piece of recorded music. Consumer speakers are much more music friendly, in the sense that they make even mediocre masters or mislead eq-adjustments sound acceptable. Find out the truth about the music you hear! If you don’t like it with the neutral eq-setting, try different music.

One exception! If you are desperately un-musical, lowering the key musical frequencies by boosting highs and lows (and pushing the important loudness knob!) will help you move the irritating differences in musical compositions to the background.