Comb Filtering

Define the discrete transfer function for a comb filter.

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combFilterModel[f_, \[Alpha]_, sr_: 44100] := TransferFunctionModel[{{1/( 1 - \[Alpha] z^-Round[sr/f])}}, z, SamplingPeriod -> 1/sr]

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combFilterModel[300, \[Alpha]]

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Plot the transfer function using BodePlot.

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BodePlot[combFilterModel[300, -.9], {0, 20000}, ScalingFunctions -> {"Linear", Automatic}, PlotLayout -> "Magnitude", ImageSize -> Medium]

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Filter an audio object using RecurrenceFilter.

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a = AudioNormalize[Import["ExampleData/rule30.wav"]]

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RecurrenceFilter[combFilterModel[300, -.9], a]

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