Ive been playing around with biquad and filtergraph and just as a test I fed in the same values as in a bell curve on EQ8 (in ableton). Then I sweep from lowest to highest frequency value (using an LFO). However, biquad sounds completely different to EQ8 (really high pitched, no low end, with peaknotch and resonantfilter). How can this be when I have fed the same values into it? Surely it is just sweeping past exactly the same frequencies?
My guess is that biquad is doing something exponential and spending more time on the higher frequencies, and therefore resulting in a higher pitched sound. Ive tried using logarithmic and linear and linear is the only one that sounds close. Should I be using some kind of exponential curve to focus more on the low end of the frequencies?
Would it be better to do this type of analysis with a svf~ filter?, or is there something obvious I might be doing wrong with biquad thats causing such different results?