Using FFT to filter the signal

Hello, i am using fft to work as an equilizer. I am recording and saving the sound as .wav file and taking fft of the time domain signal. Now i wish to ask the users to define the rannge of frequency that they wish to amplify and suppress and change the amplitufe of fft respectively. I dont know how to proceed further and I am stuck at this part. Please help!

Answer 1

[Sai Sri Pathuri]

You may design a filter with passband that depends on user inputs and apply a gain to that passband. Following answer may help.

https://in.mathworks.com/matlabcentral/answers/439517-filter-specific-frequencies-in-an-audio-file?s_tid=answers_rc1-2_p2_MLT