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scaling linear to logarithmic: using slider to control biquad filter cutoff


DJF
April 26, 2012 | 3:41 pm

I am wanting to control the cut-off frequency of a biquad filter with a slider or dial. I have noticed that the scaling of a slider to a filter, i.e. [0 127 0.0001 22000], does not work so well as the filter is logarithmic by default. Can anyone advise me on a way around this?


April 26, 2012 | 6:11 pm

if you can’t find the expression [linedrive] might be of help.


April 26, 2012 | 8:01 pm

[curve] or something like that maybe?



DJF
April 26, 2012 | 8:34 pm

I will try both of those suggestions. Someone told me that to map a 0 127 linear to 0 22000 logarithmic scale you should carry out the equation log127(2200). Does anyone know how I would go about doing this with the expression object?


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