Wikipedia says about the Equalizer: “The Equalizer is a device (or part thereof) that is used to adjust the frequency characteristics of audio signal by amplification or suppression of certain parts of the sound spectrum. If it does not say anything to you, it’s simply a device that will change the volume of certain frequencies of sound. And in the whole range from about 20Hz to 20000Hz.

The problem is that every sound is unique and sounds differently in different environments. It is very difficult to edit the frequency characteristics of an audio signal by the equalizer so the sound’s quality is good everywhere. If you multiply this by the whole group of sounds in your recording which interact with each other simultaneously, the work with the equalizer may appear as something quite impossible. This article should help you understand this area and help you determine where and what to change to achieve a very good sound.

The main types of equalizers

Frequency aperture (high -pass and low pass filter)

These devices can usually do only one thing and that is reducing the relevant frequency range (Treble or Bass). High-pass filter is used mostly to remove the bass and low frequencies. For example, an annoying resonance of the bass guitar or kick drum. Low-pass filter on the other hand is used to remove high frequency, for example noise created during the bass guitar recording.

Graphic equalizers

Graphic equalizers are usually equipped with traction potentiometers that can amplify or attenuate a certain frequency. Number of potentiometers determines the type of graphic equalizer. You can find five, but also thirty channel EQs. The frequency range is usually divided equally between the individual channels with a central frequency and its bandwidth. The main advantage of the graphic equalizer is that you can make a change in the area that corresponds with the channel. The more channels, the more detail you can focus on. Conversely, if you adjust the frequency for the five-channel equalizer, frequency range that affects your edits will be much larger. Another advantage is a graphic visualization setting. You can tell almost immediately what frequencies and how they are regulated.

Parametric equalizers

Parametric equalizers solve the problem of graphic equalizers with the ability to accurately set the central frequency and extent of the surrounding frequencies affected by your adjustment.


Each tone corresponds with a fixed frequency. Everything derives from the so-called basic tone – the general pitch “a” (a4) with a frequency of 440 Hz. A table of frequencies of individual notes can be found here.
The frequencies of individual notes are important mainly for scientific purposes. For example, over time the frequency of the general pitch “a” moved up to 442Hz . Many modern musicologists are fighting long discussions about this. For us, however, it is important to identify specific areas and frequency of the different instruments.


Pop, Soul, Funk, Rock

  • Hi -pass filter around 30Hz – for clearer sound of the bass, as kick drum usually interferes with the bass in this area.
  • A reduction of 5 to 10 db around 300Hz – to reduce the resonance and for better clarity
  • Increase of 1-3 db around 3000Hz – for greater penetration and sharpness

Similar setting is for example used on Toms. You only need to be aware of the possible conflict with bass and it is suitable remove about 2 to 4 db in the area around 400Hz.

Hip-hop, Drum and Bass, Techno

  • Hi -pass filter around 30Hz – for clearer sound of the bass, as kick drum usually interferes with the bass in this area.
  • The increase of 2 to 10 db around 50-100Hz – saturation
  • A slight increase of around 1 to 2 db around 300Hz – to increase the resonance
  • Increase of 1-3 db around 1500 – 3000Hz for greater penetration
  • Reduction up to 10dB above 5000Hz – for even greater dilution of sound and removal of high sound frequencies that are not suitable for hip-hop


  • Reduction of resonance around 300Hz
  • Increasing of penetration about 2000Hz

You should get rid of all annoying bass frequencies that resonate. Here is a short guide on how to find these badly resonating frequencies:

  • Let play bass in solo mode.
  • Select the narrow bandwidth and adjust the frequency gain to the maximum.
  • Move frequency to the left or right and listen where it is resonating the most.
  • Than turn down the frequency as needed. If you select only this frequency, this should not affect the sound of bass so much, but it greatly helps to eliminate bad frequencies.
  • Repeat as necessary, but be careful not to dampen the bass too much and destroy the sound.

Of course, you can further edit the bass, for example, you can increase the frequency of around 40Hz to achieve a dense bass sound. Slap bass can sound really good if you increase the frequency around 7000 to 10000Hz to highlight the slapped sound.


  • The increase of 2 to 10 db around 5000 to 6000Hz for the enhanced sound
  • The increase of around 2-6 db 100Hz for greater depth of the sound
  • Reduction by 2-5 db around 300Hz to improve the readability of the sound
  • The increase of 1 to 10 db around 800 to 2000Hz to increase the penetration


  • High -pass filter up to 200Hz, maybe even more
  • The increase of 3 to 6 db around 10000Hz for clean and clear sound
  • The increase of 2-5 db around 4000 to 5000Hz for sharpness
  • Sometimes it is useful to slow down around 1000 to 3500Hz, as these frequencies are unpleasant to the human ear

Singing and vocals

Singing is usually good to let without the EQ. The reason is our great sensitivity to any change in the character and vocal color. Sometimes you can improve the sharpness by adjusting the frequencies around 5000 to 6000 Hz. You can also reduce the frequencies in the area of irritating frequencies (somewhere between from 1000 to 3500 Hz).

If vocals are too illegible for you, try also to reduce the frequencies  somewhere around 300Hz.

For background vocals there is a good idea to reduce frequencies between 3000Hz and 4000Hz and conversely increase these frequencies at the lead vocals.

Rap and spoken word

Again, here are the same as the vocals with regard to the temperance in the use of EQ.

  • The increase of 4 to 10 db in the area around 2000Hz for better readability of the voice
  • The increase of 2-6 db in the area between 2000 and 5000Hz


  • The increase of 1 to 5 db of around 2000Hz for better readability
  • Reduction of 1-2 db in the area around 400Hz to reduce the resonance
  • The increase of 1 to 5 db of about 10000Hz for bright and clear sound


  • The increase of 1 to 5 db in the area around 4000Hz for better readability and clarity of the sound
  • High -pass in the area around 40Hz

For general use, it is appropriate to remember the following:

  • 30Hz – lower bass region, in this area it is appropriate to use high-pass filter to remove noise and resonance. Bass in contrary might be a little bit increased in this area sometimes to achieve the so-called boom effect.
  • 100 to 200 Hz – sound saturation.
  • 300Hz to 2000Hz – colour of sound, there is necessary to give attention to the resonating around 300Hz  and possibly lower frequency in this area.
  • 2000Hz – clarity of sound.
  • 3000Hz – 5000Hz  clarity and purity of sound.
  • 10000Hz – Clarity and purity of sound

These values are only illustrative. The resulting set will follow the characteristic of recordings and instruments. However, I think that for basic orientation the guide is quite sufficient.

A few tips for using EQ:

  • Begin with the EQ set to zero.
  • First listen and then start adjusting the EQ. Never try to change something without you knowing what you want to achieve.
  • Remove bad and ugly -sounding frequency. Use a narrow band (bandwidth) and turn down the frequency. For high frequencies, use medium- wide band for a more natural effect.
  • Don’t worry to experiment and try different settings. If you do not know what to do, try to start from pre-selected settings.
  • Adjust frequencies according to the best of your conscience and consciousness.
  • Listen and compare the result with the original. Attention, the use of EQ can enhance the original sound or weaken, when comparing try to compare equally loud sounds. Therefore, it is sometimes necessary to reduce or, conversely, increase the volume to compensate for changes you made to the EQ.


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