Chebyshevs band-reject freq pos not centered

Oh, come on guys, here we go again… see the picture and see how digital filter freq is at around 11 khz and i clearly see 5 khz pass in spectrum. Who is messing with who here?

I’m curius about this too, looks like the chebyshevs band-pass/limit mode actually has the freq slider mapped to set the higher boundary of the filter band and the q slider to lower boundary; unlike the more typical filters where you adjust the center and width of the filter band. I thought it’s intended and just use it as is.

Yes, bring in some ripple to see it more clearly/defined. The freq seems to be about the position of the upper peak brought by the ripple, and not the middle of the band/notch. The ripple is the whole point of these filters, btw, chebyshev filters spring off from some special analog design where you would trade uneven response in pass- or stopband (the ripple) for having a steeper slope of the filter. Use butterworth when you want precision, they sound much more balanced. The chebbies seem like rather “artistic” filters than “tools”, and do have some spacey ting with them.