FILTER:

There are circuits that are capable of selectively filtering one frequency or range of frequencies out of a mix of different frequencies in a circuit. A circuit designed to perform this frequency selection is called a filter circuit, or simply a filter. A common need for filter circuits is in high-performance stereo systems, where certain ranges of audio frequencies need to be amplified or suppressed for best sound quality and power efficiency. Equalizers and crossover networks are examples of filters, designed to accomplish filtering of certain frequencies.

Filters are of different types;

• Low-pass filters
• High-pass filters
• Band-pass filters
• Band-stop filters
• Resonant filters