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General Category => General Board => Topic started by: Lunatico on June 06, 2025, 07:35:47 PM

Title: Equal intervals 2
Post by: Lunatico on June 06, 2025, 07:35:47 PM
Hi
In soundfile-Filter- Equal intervals 2 (Low Freq-High Freq) bands defined by interval size, the interval semitones created are tuned in equal-temperament or in just intonation?
Title: Re: Equal intervals 2
Post by: Robert Fraser on June 07, 2025, 12:28:45 PM
I think you're referring to CDP's FILTER BANK 6, which tunes filters in equal intervals of so-many semitones. I would expect these to be in equal temperament (though the CDP documentation doesn't clarify this). If they were in just intervals, you could soon end up with some pretty "unjust" tunings: for example 3 equal-tempered thirds coincide with the octave, whereas 3 just 3rds piled up give slightly less (125/64 = 1.953125 instead of 2.0).

If you want to set your own frequencies, check out FILTER VARIBANK, which uses a text table of frequencies (or MIDI notes) and amps. You can easily load a text file of frequencies tuned to whatever you want. This is one of CDP's most powerful tools (in my opinion), and it's time-varying.
Title: Re: Equal intervals 2
Post by: Lunatico on June 07, 2025, 01:33:04 PM
Hi Robert!
A lot of thanks for your help and for creating this awesome and creative software.
I don't know what the structure of the text file should look like?

C1 32.70 Hz
C#/Db1 34.65 Hz
D1 36.71 Hz
Title: Re: Equal intervals 2
Post by: Robert Fraser on June 09, 2025, 12:18:38 PM
For Varibank, you want a datafile something like this:
0.00  110 -3dB   220 -3dB   330 -3dB   440 -3dB   550 -3dB 660 -3dB
that is:
time Freq1 Amp1  Freq2 Amp2 etc. - all in one line (even if that overspills in your text editor. don't put a carriage-return there)
The notes here are the first 6 harmonics of A1 (just below the bass clef), so those are in just intonation (!): the equal-tempered C# is 554.37, not 550.

This is for Varibank Mode 1 - filter bands as frequency - for Mode 2 (MIDI) the numbers could be:
0.00  45 -3dB   57 -3dB   64 -3dB  69 -3dB   73 -3dB 76 -3dB
which are equal tempered, though you can have fractional MIDI values, e.g. 550Hz is MIDI 72.863.

Each line begins with a time value in seconds, and values are interpolated between each pair of lines. If you don't want pitch glissandi, insert a copy of the previous line with a time value just below your next set of values, like this:
Time
0.00 .... first set
0.0999 ... copy
1.00... second set

In the above, -3dB works quite well, but you need to adjust it as required.

* * * *
Thinking of just intonation again, what value might you give a C#, relative to a C? Would it be the pure-3rd of an A, itself a pure 3rd up from an F (2/3 of C), or maybe a Db (a fifth down from an Ab, a pure-3rd down from the C?)
Title: Re: Equal intervals 2
Post by: Lunatico on June 09, 2025, 11:11:59 PM
Hi
Robert a lot of thanks for your detailed answer.
I've tried it and it doesn't work, I must be doing something wrong.

https://ibb.co/Wv6vMZ03 (https://ibb.co/Wv6vMZ03)

I just uninstalled Soundshaper 6.4 (because I read on the forum that is withdrawn) and i have installed version 6.3 and got the same error.
Title: Re: Equal intervals 2
Post by: Robert Fraser on June 13, 2025, 08:34:32 PM
Thanks for the video. You got an error because you didn't actually supply any data - the file was clearly empty. Some template examples are supplied with the program (in a folder TXT) and that selection  should come up automatically when the parameter is clicked. Check your settings for User Data Files: TXT is supplied within the CDPR8 folder (or whatever you might call it). This folder should have the following sub-folders: Soundshaper6, TXT, and _cdp (plus, optionally. docs and docs-pdf).   
Title: Re: Equal intervals 2
Post by: Robert Fraser on June 14, 2025, 02:49:35 PM
Hi,
Quote from: Lunatico on June 14, 2025, 11:36:23 AMI don't understand what I have to do to make it detect the data files? Create a folder called User Data Files inside the TXT folder?
https://ibb.co/wNzjx0SH (https://ibb.co/wNzjx0SH)

Certainly not!
TXT is the default folder for data files and I see from the video that you already have it in the correct place. (C:\CDPR8\TXT See Settings: User Data Files)
(https://www.ensemble-software.net/images/FORUM/Varibank-folder.jpg)

When you select the process, a default data file should come up automatically - either VaribankF.txt:
(https://www.ensemble-software.net/images/FORUM/VaribankF.jpg)
or VaribankM.txt:
(https://www.ensemble-software.net/images/FORUM/VaribankM.jpg)
You can click on the OPEN button in the data box to access the folder and select a different file:
(https://www.ensemble-software.net/images/FORUM/OpenDatafile.jpg)

Notice that I had to select .txt files (Okay - it should do that automatically, I'll fix that...) I have also put a shortcut in the folder to my own files (RF-Varibank), which could be placed anywhere.

I can't think why this wouldn't work for you, especially as you have the TXT folder in the default location. These examples should give you an idea how to create your own.
Title: Re: Equal intervals 2
Post by: Lunatico on June 14, 2025, 05:55:46 PM
Hi
Robert a lot of thanks for your great help and your time to do the answer.
Sorry; I replied to you and deleted it because I discovered just what you replied to me by investigating the TXT folders.
A powerful tool but I sense that if you know how to use it; I still have doubts and questions that I'm sure you will clarify:
1- I have seen in a tutorial and I have tested it in practice that it is better to activate the checkbox Options : Double filtering ?
2- Filters can be subtractive or additive, they remove or emphasise frequencies.
In the case of Filter-Varibank they are additive,emphasising?
3- There are two ways of structuring the text configuration of the data file: horizontally and vertically:

- Horizontally :
0.00  110 -3dB  220 -3dB  330 -3dB   440 -3dB  550 -3dB  660 -3dB (A chord sounds on the second 0.00 (the six simultaneous harmonics)?.

- Vertically :
0.00  110 -3dB 
1.00  220 -3dB 
2.00  330 -3dB   
3.00  440 -3dB 
4.00  550 -3dB 
5.00  660 -3dB (The six harmonics sound sequentially in a kind of smooth sweep (like a fused arpeggio)?.

- The imported sound to which the Varibank-Filter is applied is important, should it be a constant, long lasting sound like a pad, a drone? 
Does the note of this imported sound to which we apply filter-varibank influence the harmonics we apply, for example the imported sound is a drone of the note G2, in the example shown is the first harmonic from A2 110 Hz, would the six harmonics sound as they are _A2_A3_ E4_A4_C#5_E5 above the original G2 or would they sound the original G2 and above from the sixth (A2) of G2 (E3_E4...) ?

- The (HARMONICS) number must be the same as the number of harmonics you write in the text of the data file (in our example six (6)) ? 



Title: Re: Equal intervals 2
Post by: Robert Fraser on June 15, 2025, 10:16:27 PM
Hi,
1.
Quote from: Lunatico on June 14, 2025, 05:55:46 PMit is better to activate the checkbox Options : Double filtering ?
Double filtering often gives better results

Quote from: Lunatico on June 14, 2025, 05:55:46 PM2- Filters can be subtractive or additive,
Filtering is always subtractive - you're taking something away. Think of of a sculptor fashioning a shape out of a block of stone.
'Q' sets the sharpness of the filter's frequency response around its central frequency - a higher 'Q' will be be more focussed on that frequency, but is likely to be quieter - hence the GAIN control to boost the signal up again. You're boosting the resonance of the filters.

It's important to understand that we can't filter out what isn't there. Your example of the G chord (or G-based drone) is a good one. Against the A harmonics, we won't get much of a match; but what there is will resonate. A noise-based sound (like the sea) is often a good source to experiment with, because we can tune that into something more musical. Another trick is to mix some differently pitched sounds together before applying the filtering.  You might care to compare VARIBANK with spectral TUNE, which moves the frequencies to fit the given template (same format as for Varibank, so the profiles can be shared). Even here though, if you tuned birdsong against lower frequencies, only the harmonics of these frequencies would match. It won't magically transpose the original pitches down. Same with vocoding, which is also a filtering technique.

Quote from: Lunatico on June 14, 2025, 05:55:46 PMThe imported sound to which the Varibank-Filter is applied is important, should it be a constant, long lasting sound like a pad, a drone?
As you say, a constant or drone sound can be a good source for applying filters. You can then rhythmicise the result in various ways.   
Title: Re: Equal intervals 2
Post by: Lunatico on June 16, 2025, 06:50:02 PM
Hi

Robert; Thank you very much for your answer-masterclass, very interesting!

- I don't see in Soundshaper´s effect processors (like this Filter Varibank) a dry/wet regulator.
You can hear the original signal in the background, is there a way to hear only the processed signal (WET) ?
Title: Re: Equal intervals 2
Post by: Robert Fraser on June 17, 2025, 08:26:27 AM
See the new post WET-DRY in CDP for my answer.  In Soundshaper, there is already a new BALANCE option (which needs no parameters) - this raises or lowers the maximum level of the process output to match that of the input. I'm planning to have more "add-on" facilities and I've been working on how to do this within the program. MIX BALANCE (for wet-Dry) is top of this list and MORPH is another possibility. 
Title: Re: Equal intervals 2
Post by: Lunatico on June 18, 2025, 10:03:17 AM
Hi
A lot of thanks for your help Robert.
Yes, it would be very interesting to have Dry/Wet and Morph parameters in the processors.