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Combining multiple Cauer bandpass into one filter

Started by af4e...@yahoo.com January 30, 2008
Hi,
I have an audio application where I can selectively filter an input signal by choosing 1 of 16 Cauer filters with rather steep rolloff, 80db (designed using MATLAB ellip(), cascaded SOS, but running in my own C-code). These filters cover the entire Nyquist range in equally-spaced, non-overlapping bands and perform very nicely.

My problem is that I would like to combine one or more filters to create, in effect, a multiple-passband filter. Since the bands don't overlap I could simply filter for each band separately and add the results, but this seems to be inefficient.

Is there a way to combine the filters themselves on the fly into a single filter with the desired passbands that only needs to be applied once? Or do I need to take an entirely different approach?

Thanks,
AF4EX