[hannesmenzel]

Thanks a lot. I will examine your answer slowly. Btw, what a pleasure that you answering is the one who lead me onto the first steps of audio programming (biquad soruce). I'm trying to get into it since a couple of weeks (including learning c++). My testplugin is a channelstrip using some open source algorithms (chunkware's dynamics, your biquads, enhanced with some other filters from Will Pirkles book, soft saturation algo from musicdsp.org). What is actually my testbed is this: