7 Band Audio Equilizer (Implementation in GUI)
One of the most used methods in digital signal processing is audio equalization. Audio equalizers can be used to manipulate signal frequencies to improve sound quality for different listening environments. During analog to digital conversion, audio signals are subject to phase shift, quantization noise, and electromagnetic noise that can be reduced with the help of audio equalizers. Applying filters across multiple bandwidths and using algorithm modification can alter inaccurate signals in order to provide a higher quality output. The purpose of developing an equalizer is to limit these factors that have a negative impact on the quality of an audio signal, which can be accomplished by boosting or cutting parts of the signal.
Method of Implementation
The design of a multi-band equalizer begins by obtaining the input signal and gain values for each filter. It is important to note that MATLAB uses the normalized magnitude instead of the decibel value; therefore, this input parameter must be converted. To build the filters for signal equalization, the Butterworth function in MATLAB was used alongside digital filters and amplifiers. The Butterworth filter design allows users to easily customize the number of bands and the filter parameters required for specific design purposes. Once the signal has been equalized in Simulink, the signal is reconstructed to obtain the output sampling data. This 7-band equalizer design utilizes a ‘lowpass’, ‘highpass’, and three ‘bandpass’ filter types in order to equalize an input signal.
find attached file for more details