How to shift the center frequency of an IIR filter I have a pre-designed in-series 14th-order IIR filter in second-order sections. Problem is, when I simulate and measure the behavior in my codec, there is a frequency shift downward (as compared to the MATLAB prediction). Is there a simple way to alter the coefficients in such a way to shift the center frequencies of each band? Thank you.
The problem was an incorrect sampling rate issue, as a lower sampling rate than the designed rate caused the center frequency shift downwards. Today I learned something about the relationship between sampling rate and IIR coefficients (there is a proportional relationship between sampling rate and center frequency).