Filter networks
John Bird · 2021
In circuit theory, a filter is an electrical network that alters the amplitude and/or phase characteristics of a signal with respect to frequency. Filters are often used in electronic systems to emphasise signals in certain frequency ranges and reject signals in other frequency ranges. Electronic filters are electronic circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both. Filters are used in electronic music to alter the harmonic content of a signal, which changes its timbre. A filter network containing no source of power is termed passive, and one containing one or more power sources is known as an active filter network. A high-pass filter with cut-off frequency greater than 250Hz would also remove the interference, but some of the lower frequency components of the audio signal would be lost as well.