Graph showing a band-pass filter. The x-axis is the frequency of sound from low to high, and the y-axis is the amplitude or amount of sound from silent to loud.
A filter which allows frequencies between a low and a high cutoff frequency to pass, filtering out all other frequencies. Specifications for a bandpass filter are usually given in terms of a center frequency (where the top of the response curve is) and a bandwidth, rather than stating the low and high cutoffs. Depending on the filter, the bandpass may be adjustable independently of the resonance or Q.