Audio Filters Guide

An audio filter is one of the most essential building blocks of audio electronics, and it is a processing technique used to manipulate sound signals in a specific manner.

An audio filter can modify the frequency response of an audio signal, change its tone or texture, remove unwanted noise or artifact, or enhance specific aspects of the audio. 

In essence, an audio filter is a hardware device or software program that is designed to filter the frequency characteristics of an audio signal. The basic idea behind a filter is exactly as it sounds - they filter some frequencies out, and let others remain. 

With audio filters, we can filter specific frequencies, or whole groups of frequencies, known as bands. You can see them everywhere in the audio world, but to use them, you have to know how they work, and which filters are best for each purpose.

First off note that there are many different types of audio filters, including low-pass filters, high-pass filters, band-pass filters, and notch filters, among others.

Each type of filter has its own unique characteristics and can be used for different purposes in audio processing.

⪫ A low-pass filter (LPF) is a type of audio filter that allows low frequency signals to pass through, but blocks or attenuates high frequency signals.

⪫ A high-pass filter (HPF) is a type of audio filter that allows high frequency signals to pass through, but blocks or attenuates low frequency signals.

⪫ A band-pass filter (BPF) is a type of audio filter that allows a specific range of frequencies (also known as a band) to pass through, while blocking frequencies below and above this range.

⪫ A band-stop filter is a filter that allows us to let everything pass, while selecting a band of frequencies to remove

⪫ A notch filter is a filter that allows us to remove or reduce a specific frequency (this is similar to the band-stop filter, but it focuses on a targeted frequency precisely).

In other words:

⪫ A low-pass filter passes low frequencies and cuts or filters out high frequencies.

⪫ A high-pass filter is useful to cut low frequencies, so it  is sometimes called a low cut ( the same way a low-pass is occasionally called a high cut).

⪫ A band-pass filter can be useful for isolating a particular range of frequencies in an audio signal, or for shaping the tonal character of a sound by boosting or cutting a specific range of frequencies.

⪫ A band-stop filter is the opposite of a band-pass filter.

⪫ A notch filter is similar to a band-stop filter. It is called a notch filter because it creates a notch (or dip) in the frequency response at the target frequency, effectively attenuating or cutting that frequency.

Now you’ll know what common audio filters are and how to use them.

Wikipedia https://en.wikipedia.org/wiki/Audio_filter

Well, stay tuned to get more helpful pointers for creatively shaping the tone of your sounds in sound design.

Spoiler Alert ⨶  There are thousands of ways you could apply audio filters creatively!

Reference Source - https://www.native-instruments.com/en/