A Band-Pass Filter is a filter that allows only a specific range of frequencies to pass through, attenuating both low and high frequencies that are outside that range.

This type of filter is essentially a combination of a low-pass filter and a high-pass filter. The result is a peak at a specific center frequency, with attenuation occurring on both sides.

It is widely used in synthesizers to create specific timbres, isolating a range of frequencies to highlight certain characteristics of the sound.

A practical example would be an effect that mimics the sound of an old radio or a megaphone.