Books on Digital Filters
I need to implement a cut-off filter of an old analogue synthesizer as a digital filter. Since standard simple IIR filters aren't good enough, I'm looking for a good book on the subject so I could design the filter myself. The book should have a thorough discussion of IIR filter design (second-order and higher) and it should be readable to some extent. :-)
Analogue synths used low pass resonant filters for that wah wah effect.
I know, but simple second-order resonant digital filters that you find on the web sound too harsh and "digital". This is because the peak in the frequency spectrum that they create is too narrow.
Pretty good book. And free:
Well the first thing is to establish what the analogue filter is that you are trying to emulate. What is the original design (get circuit diagrams if you can) Does it get driven into non-linearities? (that's analogue "warmth") How does cutoff frequency track through the range (otherwise sweeps will sound different), and so on.
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