Filters are circuits which perform signal processing functions. They specifically are used to remove unwanted frequency components from the signal, to enhance wanted ones or both.
Filters can be of different types. In Audio however you would come across these basics filters.
– High-pass: To let high frequencies pass and block low frequencies
– Low-pass : To let low frequencies pass and block high frequencies
– Band-pass: To let only Mid Frequencies Pass and block both high and low frequencies. .
An “audio filter” is a frequency-dependent amplifier circuit and is used to alter the frequency content of a sound.
As the name suggests, “frequency” is the number of occurrences of a repeating event per unit time.
For audio signals, the number of vibrations an instrument or sound creates in one unit of time is the frequency of the sound.
Frequency is commonly measured in cycles per second (CPS) or hertz (Hz). Humans usually hear audio frequencies in the range of 20Hz to 20kHz.
Since a filter is a frequency-dependent amplifier, in its most basic form, the audio filter is most commonly used to pass or attenuate some frequency ranges. Filters are typically used to remove unwanted frequencies in a given sound. These unwanted frequencies are also called “dirt”.
In this video, we break down in a simple way how to use a filter to remove unwanted dirt in an audio signal.