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Re: Anti aliasing filter : I research a code source
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Re: Anti aliasing filter : I research a code source


  • Subject: Re: Anti aliasing filter : I research a code source
  • From: Admiral Quality <email@hidden>
  • Date: Sat, 10 Sep 2011 11:45:30 -0400

You can't filter out alias frequencies as they can appear anywhere
above, below, or within the wanted harmonics. You need to make a
bandlimited oscillator so you don't generate them in the first place.
Look up MinBLEP for the most common technique.

- AQ

On Sat, Sep 10, 2011 at 9:11 AM, herve.noury <email@hidden> wrote:
> Hello,
>
> I build an AU instrument. With some linear functions, I created an oscillator able to give rich sounds. But when I play them in the treble , I've got an horrible noise, like a sinus noise mixed with a bass white noise!!
>
> I've included yet in the process a LPF filter copied on the Filter Demo example. But even if I cut a lot of harmonics, this noise is still there. It disappears only if I cut the signal at all!!
>
> I should, before adding the float out number to the left and right arrays, include another kind of filter. Could someone explain to me what to do? Would someone have an example or a code source to show to me?
>
> Thanks a lot for your answer.
>
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References: 
 >Anti aliasing filter : I research a code source (From: "herve.noury" <email@hidden>)

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