Aliasing foldover problem


    Mar 05 2014 | 7:04 pm
    Hi everybody. Firstly, some words about my project. I'm working on some insane idea - reversed subtractive/additive synthesizer based on noise as source.
    And additive possibilities is my main problem for now. I can't figure it out why my poly~ object is distorting signal on high octaves (see screenshots with spectrum), even if i'm upsampling it to 8. I think that it is happening because of foldover, but i'm not sure about that. That is why i'm asking for you to help me.
    Also i really can't understand the nature of clicks that are appearing when i'm triggering the notes with low attack values.
    I will be very thankful for any advice or any direction to what info should i dig, about this problems.
    On screenshots, as you can see there is a huge amount of low frequencies when i'm triggering high notes. Also sometimes this gaps covering all spectrum. And sometimes notes playing to louder then it should.

    • Mar 09 2014 | 10:38 pm
      UP
    • Mar 09 2014 | 11:30 pm
      Add: Also found some info that biquad~ is not a best choice for frequency track... Tried to remake device with reson~, at higher octaves C7 - G8, problems above are disappearing, but tones are becoming more distorted.