James W. Morris wrote: >Is it possible to code resonant linear filters which use an array as I do, >or will I have to go on a higher mathamatics course and get my head round >fancy bi-carbonated equations?
resonant filters use recursion; the algorithm sometimes is coded as 'take this input sample and give me an output sample' for readability but is easily adapted to arrays. the maths behind them are intricate (to me at least), but you don't need too firm an understanding of the theory to actually use them. you'll find code examples for the algorithm and the computation of the recursion coefficients in almost every major audio synthesis/processing package or at musicdsp.org . steve's ladspa set has a very nice state-variable filter (svf) which lends itself well for resonance and reasonably quick parameter changes. you may want to try it first before resorting to coding your own. tim ps: the svf sounds better to me with the 'very slight waveshape for extra stability' removed.
