What is a Parametric Equalizer?

Parametric Equalizer

Parametric Equalizers are most often used when very fine adjustments of an audio signal are needed.

There are a lot of equalizers, both analog and digital. Like the name says, Parametric Equalizers have several “parameters” to control several filters that can be applied to an audio signal.

In order to be named parametric, an equalizer has to have at least the following filters: Gain, Q and Frequency.

Gain:

The audio signal which is delivered by a plugged instrument or a player of any kind can be amplified. This amplification, done by an electronic circuit, is called “gain”. Often, gain is expressed as decibel value, for example 5 dB of gain. Another word that could be used for gain is Amplitude, the strength of an audio signal.

Q:

Refers to the resonance of an audio signal. The technical explanation is that Q is the energy stored divided by the energy dissipated per cycle in a network. Q also means quality factor, determining and being the unit of measure of the bandwidth (frequency span) of a signal. Bandwidth is the difference between the upper and lower frequencies of an audio signal. For example, the bandwidth of a signal that ranges between 3400 Hz and 300 Hz is 3100 Hz. Another explanation of what Q is could be this one: If you pluck a guitar string, it will vibrate for a long time. It dissipates just a little amount of its energy, meaning it is like a high Q mechanical filter. When you put your finger on the string it stops vibrating very quickly. Your finger has lowered the resonance of the vibrating string, removing a lot of energy. Analogue, this would be a low Q mechanical filter. Another classic high Q filter would be the Wah-Wah-Pedal of a guitar, for example.

Frequency:

The number of times something occurs per unit of time. For example, if an audio signal has a frequency of 1kHz, its period or swing rate is 1000 times per second. In the musicians realm, the frequency of the vibrations of an audio signal is directly related to the thing we hear as pitch. This relationship is not linear.

4 Comments

  1. SaM

    Very professionally written overview of the parametric equalizer. All of the components are described with detail however an audio example would be nice to be added. I would like to know more about the gain, q and frequency filters. One more thing – what are other filters a good parametric equalizer should have?

    Reply
    1. Fabian (Post author)

      Hi there! As this site grows I am going to add more information on gain, q and frequency. A parametric equalizer can have high-pass or low-pass or high-shelf and low-shelf as well as reverb (for example).

      Reply
  2. Cathy

    Hi there Fabian, I am helping a friend set up a home based business and he’s an expert in making beats. I am wondering if you are affiliated to any company and if you could recommend some for him? He’s also looking for a website platform. What’s the one that you are using for yours? Thank you in advance.

    Reply
    1. Fabian (Post author)

      Hi Cathy, I am still in the beginning of selling my own beats, so I don´t really have a company or platform which I could recommend you. Can you specify what you mean? Does your friend need a location on the internet where he can share and sell his beats or does he need a website?

      Reply

Leave a Comment

Your email address will not be published. Required fields are marked *