Audio Equalizer with Fractional Order Butterworth Filter

An attempt is made to implement Fractional order infinite impulse response (IIR) Butterworth filter. This has given sharp cut-off frequency and better spectral response. An audio application like CD player, digital audio equalizer is one used to make sound as one desire by changing filter gains for different audio frequency bands. Other application include adjusting the sound source to take acoustics into account removing undesired noise and boosting the desired signal in the specified pass band of Butterworth is key block in equalizer. Here, an attempt will be made to implement such band pass filters in equalizer using fractional order Butterworth filter (FBWF). The principal behind to develop FBWF is in complex w-plane(w=s^q, q is realnumber). In S plane Butterworth filter and implemented in integer order, where in complex w-plane Butterworth filter will be implement in real order. Detailed mathematical calculations will be presented.