What do i send to Pitch for a standalone audio (ladder) filter?

Bolle
Bolle Member Posts: 349 Pro

I need to build a simple standalone Ladder Filter/LFO combo, because my DAW doesn't have one.This is for filtering audio tracks. What info do i send to the Pitch input of the Ladder Filter?

Greets,


Bolle

Comments

  • Paule
    Paule Member Posts: 1,328 Expert
    edited December 2022

    With a right click at the P input you can choice a controller knob and look what default ranges are in the properties.

  • Bolle
    Bolle Member Posts: 349 Pro

    How do i make sure i get the best possible sounding filter for audio purposes?

    What constant do i set the Pitch input to is what i'm asking.

    Greets,

    Bolle

  • Sunborn
    Sunborn NKS User Library Mod Posts: 2,336 mod

    You never add constant value to a Pitch, it will be static! ...you either add an "in" (to get values from another module), either add a knob (usually the cutoff)

  • Bolle
    Bolle Member Posts: 349 Pro
  • Studiowaves
    Studiowaves Member Posts: 453 Advisor

    There should be several articles online discussing what frequency areas do. For instance 20 hz is typically the lowest tone a person hears as a pitch. Below 20 Hz are generally movements over very large structures that are very slowly moved on a surface that slowly moves. Check out the Fletcher Munson curve. It shows what frequency ranges are more or less sensitive. Other than that make a band pass filter with a knob on it from 20 to 20k. As you turn the knob you'll become familiar with the sounds of the spectrum. Also, I would use the pitch to frequency module and use knob values from say 0 to 127. This is the midi note range. But it makes a logarithmic sweep which means octaves are the same distance apart on the dial. Use the number display module on the output of the note to frequency converter so you'll know what frequency are your learning. I think it would be best to use a simple band pass filter of 6 db per octave. It will give you a pretty good perspective of what each frequency area does. After you do that, you'll know what frequency to use on your filter. Have fun

  • bolabo
    bolabo Member Posts: 97 Advisor
    edited December 2022

    What info do i send to the Pitch input of the Ladder Filter?

    The standard 'Pitch' input of Reaktor modules (primary and core) generally expects a value between 0 and 120, where each number represents a single semitone step. The values are the same as the 'MIDI note numbers', so 60 = C3, 61 = C#3 etc

    The pitch input for blocks is different, for blocks the value range for 'PITCH' ports is between 0 and 1 for the 10 octaves between 0 and 120, so steps of 0.1 give you octaves. The ports on blocks are always 'normalised' between -1 and 1.

    When a pitch signal enters a the core cell of a block you generally need to multiply it by 120 to convert it to the range used by 'Pitch' ports of the factory core macros.

    Although most of the factory core macros for filters have a 'cutoff frequency' port rather than a 'pitch' port, it's usually more 'musical' when modulating the cutoff frequency of a filter to work with pitch values rather than frequency values, because of the logarithmic scaling that Studiowaves mentioned. Therefore, in core, you would convert the incoming modulation signal (between 0 and 1) by scaling it up to the pitch range first with an X-Fade macro, then using the 'P2F Convert' macro to convert the pitch value to a frequency value, like this:


  • Studiowaves
    Studiowaves Member Posts: 453 Advisor

    What you did is correct. You could also just have a pot that goes from -20 to 130 and skip the crossfade. I would put the numeric panel module on the output of the P to F convertor. Then as you turn the dial you can read what frequency it is. That frequency is the cutoff of the filter. So basically dial in the frequency as you see fit. That's all there is too it. Bear in mind the P2F is nice as it corresponds to midi note numbers. So you might also have another numeric panel next to the other. One will show the midi note middle A as 440hz or its frequency. The other will show the midi note for middle A as 69. Here's the chart for the numbers.

    Middle A is a standard tuning fork frequency. Tap it and it vibrates at 440hz.

    I hope this answers your question.

  • Studiowaves
    Studiowaves Member Posts: 453 Advisor

    Thought I'd give a little time for experimenting with your filter. Have you figured out that what you asking is an arbitrary question. You can put any number in there, can't you. It depends on what you are filtering. I typically start my low pass filters around 1.5k when I'm filtering a bass guitar but around 8k for a bright guitar and 12k just to keep down extraneous pickup noises. Mixing sound is an add subtract situation. It's actually pretty simple but it definitely helps to understand what areas of the frequency spectrum sound like and learn what they do. So have fun learning. I wish you well my friend.

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