Q: Modulation Depth

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JamminFool
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Joined: 04 Oct 2005 21:44

Q: Modulation Depth

Post by JamminFool » 06 Oct 2005 01:42

hi,

i'm playing with modulating the cutoff and res in a filter module (either by LFO or MidiData), but i notice the Modulation Depth control only seems to act on the cutoff (i'm using it to effect the range of the modulation).

how do i control the range for the resonance?

i know i can do this using the Amount knob in the LFO, but his brings up the question of which is the preferred method (Mod Depth in Filter, or Amount in LFO)?

is there an advantage/disadvantage of one over the other in any case?

and this still doesn't help me for the case of using MidiData for both cutoff and res at once (since there is no equivalent of the Amount knob in the MidiData module).


in fact, that brings up another question (which perhaps will explain all):
how do i use the Mod. Mode = (Linear,Range Scaled) setting?

thanks for you patience (since i'm not sure if i'm even approaching the problem correctly). obviously the power and flexibility of this monster is overwhelming me. :shock:

robenestobenz
Posts: 110
Joined: 01 Oct 2005 03:08

Post by robenestobenz » 06 Oct 2005 04:15

Maybe the modulation depth is for changing the ratio of control between cutoff and resonance? It's very useful for assigning two parameters to a midi-controller - I made a patch a couple of minutes ago which uses the mod wheel to change both the cutoff and resonance of a bandpass, and without this feature the cutoff would float into inaudibility before the resonance would reach a high percentage.

Use LFO amount or volume for the effect you want, IMO.


By the way, audio and modulation signals are the same thing (or at least interchangeable) in Karma synth (like a hardware synth's signal voltage I think), so you can use the volume on the midi data module. With modulation modules, the volume slider ranges from +64 - -63 with the modulation amount decreasing as you move closer to 0. -64 essentially functions as an invert of the signal (using the above example moving your modwheel down would increase cutoff, for examples).


//edit: mind you, the mod knob is present for modules with more than two controls. In that case, I dunno. It's extremely useful either way.
Last edited by robenestobenz on 06 Oct 2005 17:04, edited 2 times in total.

JamminFool
Posts: 31
Joined: 04 Oct 2005 21:44

Post by JamminFool » 06 Oct 2005 15:10

hmmm...there's a lot here to chew on. i need to do some more experiments and get back to you, as you've raised good points, but just as many new questions.

i'll post back here after i get the kids off to school and have a chance to look at this all again :?

JamminFool
Posts: 31
Joined: 04 Oct 2005 21:44

Post by JamminFool » 06 Oct 2005 19:48

robenestobenz wrote:Maybe the modulation depth is for changing the ratio of control between cutoff and resonance? It's very useful for assigning two parameters to a midi-controller - I made a patch a couple of minutes ago which uses the mod wheel to change both the cutoff and resonance of a bandpass, and without this feature the cutoff would float into inaudibility before the resonance would reach a high percentage.
but i'm still not sure how the Mod Depth knob in the filter works, exactly.

in my example, it seems to default to controlling the Cutoff only, which is fine when that is all you want to set a range for.

i guess i need a better explanation of what the intended use is when more than one control in the component is being modulated, especially by different modulators...

Use LFO amount or volume for the effect you want, IMO.
did you mean "Amount" or "Volume" ?
because i found the "Amount" knob in the LFO Modulator works well also. Regarding "Volume" (by which i assume you mean the slider marked "Out") see below...
By the way, audio and modulation signals are the same thing (or at least interchangeable) in Karma synth (like a hardware synth's signal voltage I think), so you can use the volume on the midi data module. With modulation modules, the volume slider ranges from +64 - -63 with the modulation amount decreasing as you move closer to 0. -64 essentially functions as an invert of the signal (using the above example moving your modwheel down would increase cutoff, for examples).
yes! this presents the solution. i hadn't even considered this. using the "Out" slider in the MidiData components works perfectly for this...
thanks for pointing this out!
//edit: mind you, the mod knob is present for modules with more than two controls. In that case, I dunno. It's extremely useful either way.
yup, still looking to unlock the mysteries of the Mod Depth knob for components which have more than one knob to modulate...

JamminFool
Posts: 31
Joined: 04 Oct 2005 21:44

Post by JamminFool » 06 Oct 2005 19:55

hey, what's going on with the quote mechanism on this forum? seems to properly outline the intended quote, but no text?

doing it the same as always, but doesn't appear to work.

@robenestobenz: assume each quoted box contains the corresponding paragraph from your post in order to make sense of this.... :?

robenestobenz
Posts: 110
Joined: 01 Oct 2005 03:08

Post by robenestobenz » 06 Oct 2005 20:20

JamminFool wrote:did you mean "Amount" or "Volume" ?
because i found the "Amount" knob in the LFO Modulator works well also. Regarding "Volume" (by which i assume you mean the slider marked "Out") see below...
Yeah, both work fine.
JamminFool wrote:but i'm still not sure how the Mod Depth knob in the filter works, exactly.

in my example, it seems to default to controlling the Cutoff only, which is fine when that is all you want to set a range for.

i guess i need a better explanation of what the intended use is when more than one control in the component is being modulated, especially by different modulators...
My experience is the same (always seems to affect the leftmost knob only), though I find this useful. Otherwise if I wanted to modulate two parameters in different amounts, I'd need two MIDIdata modules. Nevertheless, it seems like an odd implementation and I don't have any real clue as to what it's for exactly. I guess we'll have to wait for Kasper to explain.

Quotes are coming up plain white here as well. Highlighting it might work, it does in Firefox at least.
Last edited by robenestobenz on 06 Oct 2005 20:54, edited 1 time in total.

JamminFool
Posts: 31
Joined: 04 Oct 2005 21:44

Post by JamminFool » 06 Oct 2005 20:42

robenestobenz,
thanks for all your input. very helpful.

the more i think about it, the more it feels like a bug that the Mod Depth only affects the 1st knob in any component. in other words, it should set the Mod Depth for the whole component, not just any particular control within the component.

guess we wait for kasper to enlighten us... :)

karmafx
Site Admin
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Post by karmafx » 06 Oct 2005 23:05

Hey guys!

some very good questions you have there.
Actually the mod depth only controls the modulation depth of the first knob in the component (or module), i.e., in case of the filter it controls "cutoff" and in the amplifier it controls "Amp".

The only reason is is like this is legacy i'm afraid, since synthesizer "mod depth" normally refers to modulation depth on cutoff only.

You can increase or decrease mod depth (center position is standard) so it should be possible to create a modulator that modulates resonance and cutoff simultaneously, but at different levels with just one mod depth knob. Having more mod knobs would clutter the interface imo.
However, of course you can always create two modulators with different settings but with scaled outputs and control modulation depth that way.

With regard to modulation mode (Linear or Range Scaled), the difference is pretty simple:
Let me explain by using an example on e.g. the cutoff knob.
Lets say is is set to 64 (=50%) and you modulate it by an lfo with full (100%) output. The cutoff knob will then rotate between 0% and 100% in both linear and range scaled mode.
Now suppose you rotate cutoff to 25%. In Linear mode it will now rotate between 0% and 75%, but in range scaled mode it will still go between 0% and 100% since the range is scaled according to the position of the knob. You can try it out for youself by enabling "show mod." on the cutoff knob, and you should see it rotate according to the above.

Default is range scaled on all knobs, except for special knobs like "note" and "octave" where linear makes much more sense.

Hope this makes sense! :D

ps: sorry the quote thing is broken...actually it works but the font is printet white on white, so you need to mark it to see it...sorry, it will be fixed once I get time.

robenestobenz
Posts: 110
Joined: 01 Oct 2005 03:08

Post by robenestobenz » 06 Oct 2005 23:42

I kind of get it, heh.

It seems to me that the modulation output is divided and applied to either side of the value the modulated knob was set to before it was modulated. So, like you say if the output is set to 100% and the modulated knob was at 50%, it rotates 50% either side.. 0-100.

In linear mode, Karma applies 50% of the modulation amount to either side of the modulated knob's initial setting even if this goes beyond the minimum/maximum range - in your example, 25% of the modulation amount is absorbed by trying to go to -25%. In ranged mode, the modulation range is offset so that it always modulates the full amount.

Is this it?



//edit: By the way, is it planned that there could be a modifier key that affects your mouse drag and allows you to fine-tune parameters for modules?

JamminFool
Posts: 31
Joined: 04 Oct 2005 21:44

Post by JamminFool » 07 Oct 2005 00:43

karmafx wrote: You can increase or decrease mod depth (center position is standard) so it should be possible to create a modulator that modulates resonance and cutoff simultaneously, but at different levels with just one mod depth knob.
you mean using the mod depth knob for the cutoff? but how do you independently adjust the depth for the res from the same modulator component? by using the 'Out' slider and/or 'Amount'? or do you mean that since there is only one mod depth knob that by definition they will be at different levels?

clearly, with all these options, the job can get done, but i'm still not sure what the intent of the design is...ie. am i doing this in the most efficient way given the design...
Having more mod knobs would clutter the interface imo.
i agree.
With regard to modulation mode (Linear or Range Scaled), the difference is pretty simple:
Let me explain by using an example on e.g. the cutoff knob.
Lets say is is set to 64 (=50%) and you modulate it by an lfo with full (100%) output. The cutoff knob will then rotate between 0% and 100% in both linear and range scaled mode.
Now suppose you rotate cutoff to 25%. In Linear mode it will now rotate between 0% and 75%, but in range scaled mode it will still go between 0% and 100% since the range is scaled according to the position of the knob. You can try it out for youself by enabling "show mod." on the cutoff knob, and you should see it rotate according to the above.
so linear mode respects the initial setting of the knob being modulated, that much i get, but i'm still not clear on when to use range-scaled. is it intended to modulate without respect to the initial setting, ie. ignore the initial knob setting? or is there even more to it than that? sorry to be dense.


btw: highlight the quoted text to see what i'm referring to in your post...

robenestobenz
Posts: 110
Joined: 01 Oct 2005 03:08

Post by robenestobenz » 07 Oct 2005 01:08

JamminFool wrote:
karmafx wrote: You can increase or decrease mod depth (center position is standard) so it should be possible to create a modulator that modulates resonance and cutoff simultaneously, but at different levels with just one mod depth knob.
you mean using the mod depth knob for the cutoff? but how do you independently adjust the depth for the res from the same modulator component? by using the 'Out' slider and/or 'Amount'?

clearly, with all these options, the job can get done, but i'm still not sure what the intent of the design is...ie. am i doing this in the most efficient way given the design...
Mod depth essentially functions for the first knob as the output does on modulation components. Say I have somethng modulating all the knobs of a component (except for mod depth). The setting of mod depth corresponds to the strength of the modulation of the first knob. 127 would mean it receives the same strength of modulation as the others, 64 would mean half as much. So if the all the knobs were modulated to 10 units above their initial value, the first knob would only have increased by 5.

JamminFool
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Joined: 04 Oct 2005 21:44

Post by JamminFool » 07 Oct 2005 01:13

yes, of course. good way to look at it.

robenestobenz
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Post by robenestobenz » 07 Oct 2005 01:20

Heh, I'm surprised (and glad) I was coherent. I thought I explained it very crappily. Whenever I try to explain my understanding of something, I always try to imagine reading it as someone else would and my conclusion's pretty much always the same - 'It's gibberish'.

karmafx
Site Admin
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Post by karmafx » 08 Oct 2005 18:29

Hey...I fixed the quote thingy ! :D

JamminFool
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Post by JamminFool » 08 Oct 2005 19:08

8)

JamminFool
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Post by JamminFool » 08 Oct 2005 19:11

JamminFool wrote: so linear mode respects the initial setting of the knob being modulated, that much i get, but i'm still not clear on when to use range-scaled. is it intended to modulate without respect to the initial setting, ie. ignore the initial knob setting? or is there even more to it than that? sorry to be dense.
is this correct?

karmafx
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Post by karmafx » 08 Oct 2005 20:09

Both respect the initial setting !

However, in linear mode:
The modulated signal is simply added to the initial setting.
(Note, this means that the modulation won't neccesarily use the full range of the knob that is modulated.)

In range-scaled mode:
The modulated signal is multiplied by a scale factor and added to the initial setting. The scale factor is adjusted so a full range modulation (-1 to 1) will _always_ use the full range of the knob that is modulated.

Lets take the previous example where we set cutoff to 25%.
Now, modulating the knob "linearly" will make it go between -25% (clamped to 0%) and +75%.
Modulating the knob range-scaled will expand the modulation above the initial setting, and compress it below the initial setting forcing it to go between 0% and 100%.

So you see range-scale usually sounds better because it uses
the full range and avoids clamping.
I don't see any need to use linear mode, except in cases like "note" and "octave" where range-scaling can make it go out of tune.

it is simple really....However, I propably need to _draw_ this in the manual to make it easy to understand ;-)

JamminFool
Posts: 31
Joined: 04 Oct 2005 21:44

Post by JamminFool » 08 Oct 2005 21:31

great post kasper.

thanks for the additional clarification. it makes sense now.

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