antialiasing filter?


    May 14 2006 | 2:53 pm
    Hello,
    Just wondering if there is a way to do antialias filtering? Perhaps an object that I could use to filter the output of the phasor~ object for example.
    Thanks for your help.

    • May 14 2006 | 4:30 pm
      You need to filter aliasing before it occurs in the signal, because you
      can't filter the aliased frequencies out of an already aliased signal. Put
      your phasor in an up-sampled poly~, followed by a lowpass/brickwall filter.
      There are different filters you could use like butterworth or FIR. I'm not
      sure what's best.
      If you just want anti-aliased oscilators use saw~/tri~/rect~
      hth, -thijs
    • May 14 2006 | 8:04 pm
      Anything in the lowpass familiy should work
      Svf~
      Onepole~
      Biquad~ (with low pass coeffs)
      -lcc
    • May 15 2006 | 5:32 am
      I have made a butterworth low-pass filter, tl.butterlp~. Butterworth
      filters have a flat frequency response in the passband. I also have a
      more expensive filter CPU-wise: tl.crossover4~. That is a fourth order
      Linkiwitz-Riley filter.
      Best,
      Trond