To adjust the tonal quality of an audio clip. As with graphic equalizers found in home or auto audio equipment, an equalize effect can to boost or cut the original signal at different frequency bands.

Equalizers are software or hardware filters that adjust the loudness of certain frequencies. Our spectrum is around 20-20,000 Hz, and the closer or closer we get to these limits, the softer things will be heard. With our cars, rooms, and speakers in various shapes, sizes, and configurations, the same note of the same instrument can sound completely different. That's why ancient amphitheaters were designed with acoustic projections in mind so they could carry sounds.

Equalizers were originally developed for physical spaces such as movie theaters and outdoor areas, places that were not designed acoustically, to “equalize” all sound frequencies. For example, some places respond better to bass frequencies, so the EQ can be turned off to avoid feedback and even slightly turned up at the top to clear things up. In general, you would be equated for physical space by taking into account a certain combination of room and equipment.

Although still used this way for live shows and the like, casual listeners can use EQs not only to correct deficiencies in their acoustics, but also for more aesthetic reasons. In your car, for example, you can't really change how far the sound travels apart from speaker balance and fading. You cannot move the speakers to better locations or change the seating arrangement. In this case, an EQ can be used to attenuate and amplify or "cut" and "boost" certain frequency ranges.

How to Sync All?

Equalizers work in intervals or "bands". Odds mean your car should have a dual-band EQ at a minimum; These are also called the “treble” and “bass” bands, respectively. Beautiful sound systems can have up to three, five or even twelve groups. Professional music equipment uses twenty to thirty bands. The more bands you have, the more divisions you have in a wide range of human hearing. Therefore, each band controls a small frequency range, thus giving greater control over the sound.


Audio filters are used to isolate bands, usually in the form of a bell around a central band. On a hardware system these filters can be quite complex, but they are quite easy to see thanks to the graphical EQs.

You can visually adjust the buttons very easily to get the sounds you want. Software EQs essentially mimic this setup, as do those on your music player of choice.