In this paper a design method of the optimum digital audio equalizers with small ringing impulse responses, by using symmetric B-spline functions is presented. It is important to have a flat frequency response for the audio equalizer. The solution is to approximate the response of each frequency band by using spline functions, that insures continuous superior order derivatives. These small ringings give a natural audition. B-splines can be combined to improve the interband independence and, at the same time, to have small ringings of the impulse response and desired frequency response.