Several Questions Re. TurboFilter

[dmbaer]

The question I was hoping Vojtech would answer was the first in the OP: where is the TurboFilter module (and the MTurboFilter plugin) going? Are we going to see TurboFilter-based implementations of classic synth filters? That would be good to know when trying to figure out what to do in future with MSF.

[Dirtgrain]

Adding a noob question on the filter:
In Zebra 2 filters, I can adjust a keyfollow knob that also affects where the cutoff point of the filter is relative to the frequency cutoff knob position, so that I can have the filter really fully engage when the frequency cutoff knob is at a lower setting. This gives me more play when applying the filter. Is there a way to achieve this with filter and MTurboFilter? As it is, with resonance turned all the way down, much of the range of the frequency knob is with the filter totally cutting off sound (in low pass mode, of course). Sorry for being so bad at verbalizing this.

[jmg8]

Yes the range of the frequency control is huge. This can feel weird at first. The filter is key-tracked as default. This is why the range is so big, because it is measured in octaves rather than frequencies. You can turn off the key tracking if you want a constant filter (this will also make the values in hz). So the default key-tracking can not be modified, it is linked to the frequency of the note being played. However you can turn the filter to constant and then use the key scale modulator source to key-track the frequency. This will give you full control over min, max and even a curve if you so wish. Hope this helps.

[Dirtgrain]

Ah, many thanks.

[gentleclockdivider]

As it is, with resonance turned all the way down, much of the range of the frequency knob is with the filter totally cutting off sound (in low pass mode, of course). Sorry for being so bad at verbalizing this.

This is because of the cheap filter algoritm , it has nothingt to do with keytracking

[jmg8]

As it is, with resonance turned all the way down, much of the range of the frequency knob is with the filter totally cutting off sound (in low pass mode, of course). Sorry for being so bad at verbalizing this.

This is because of the cheap filter algoritm , it has nothingt to do with keytracking

This is simply not correct. @gentleclockdivider
Most filters range from 20hz to 20khz, as this is the human hearing range, think of this as the useable range of the filter.
Melda's filter ranges from 1hz to 112khz. So a lot of the range will make no audible difference. This is why "much of the range of the frequency knob is with the filter totally cutting off sound"
Why is the range so big, with so much dead zone? Well, the answer to this is key tracking.
Keytracking is quite special in Melda's filters as opposed to standard key tracking you might find in other filters. Mostly key tracking will just spread the range of the filter over the keyboard. However in Melda's filter, it will exactly link the frequency of the filter to the note being played, so if you play A4 then the filter frequency will be 440hz. This is a really great way to have the key tracking set up as it is extremely musical, to have the resonating frequencies "in tune" with the notes being played.
It also means that the frequency can be measured in semitones and octaves. This is the reason why the range of the filter is so huge.

The question here was about the audible cutoff range of the filter. I know you have issues with the filter when modulating at audio rate values, however, that is not relevant to this conversation.
The range of the filter is very much "to do with key tracking"

[gentleclockdivider]

As it is, with resonance turned all the way down, much of the range of the frequency knob is with the filter totally cutting off sound (in low pass mode, of course). Sorry for being so bad at verbalizing this.

This is because of the cheap filter algoritm , it has nothingt to do with keytracking

This is simply not correct. @gentleclockdivider
Most filters range from 20hz to 20khz, as this is the human hearing range, think of this as the useable range of the filter.
Melda's filter ranges from 1hz to 112khz.

It doesn't matter what the knob value shows .
I must bee missing something then ,project sample rate is 44khz , maximum filter frequency is 22khz
I dialed in full resonance so you can clearly see the cut off peak

[jmg8]

Above 20khz, it does nothing extra, but that doesn't matter as you can not hear that anyway.
The point here is that, the AUDIBLE range of this filter is not the same as the range of the dial. However in every other filter I have used elsewhere the range of the dial is 20-20,000hz, ergo, the audible range of the filter.
For someone new, it can feel strange, like the filter doesn't do anything for the start and end parts of the dial.
However, it simply has an extended range to allow for the type of key-tracking that is used.

[DarkStar]

Melda's filter ranges from 1hz to 112khz. So a lot of the range will make no audible difference. This is why "much of the range of the frequency knob is with the filter totally cutting off sound"
Why is the range so big, with so much dead zone? Well, the answer to this is key tracking.
Keytracking is quite special in Melda's filters as opposed to standard key tracking you might find in other filters. Mostly key tracking will just spread the range of the filter over the keyboard. However in Melda's filter, it will exactly link the frequency of the filter to the note being played, so if you play A4 then the filter frequency will be 440hz. This is a really great way to have the key tracking set up as it is extremely musical, to have the resonating frequencies "in tune" with the notes being played.
It also means that the frequency can be measured in semitones and octaves. This is the reason why the range of the filter is so huge.

Semi-enlightened here

But 112 KHz seems a lot. From here:
https://en.wikipedia.org/wiki/Scientifi ... requencies
with A4 = 440 Hz, then the top key, G9 is 12,544 Hz. 112 KHz would be A12.

Ah, I see what you're saying the Frequency can be -8 octaves to +8 octaves. This is relative to the audio frequency received (the note played); that is, key-tracking. Playing A4, with the Frequency set to +8 and a Pitch moide of "Normal" sets the filter's frequency to A12 (= A4 +8o). And a lowpass would therefore have no audible effect.

If you set the Pitch Mode to "Constant", then the Frequency is set relative to the standard A4 frequency of 440 Hz and does not track the keys. The effective frequency is shown in the knob's value; e.g. 1245 Hz (+1.50 oct).

One further observation: Frequency in the TurboFilter plug-in uses the range 20 - 20,000 Hz. (Which, because of the thread title, is where I started looking!)

[jmg8]

Yes. You have it spot on.
TurboFilter inside MSF has the key-tracker version as found in the normal filter. But the plugin is 20-20k.

[DarkStar]

And I see that the Pitch panel in the MSF (and MPowerSynth) Oscillator has the same approach.

But the TurboFilter in MSF's FX section uses 20-20,000 Hz.

[MeldaProduction]

I don't really remember, but my guess is that it limits the frequency to 20..20k, so the peak is 20k despite you wanted 120k (which seems very "useful" )