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Modalys

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Modalys physical modeling sound synthesis user group

mallet force / felt connection and gain

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coraliediatkine

Hi

A few questions that regard Modaly as much as Mlys. I’ve been browsing the MaxMSP Marimba patch quite in detail to understand how to switch form Modalys to Mlys and use the FELT connection. I think these might be helpful to others. I am trying to be exhaustive for the sake of clarity.
A few preliminary notes:
1.
Looking at the script, almost all parameters can be controlled dynamically. Yet, the only parameters that are dynamically modified in the patch are:
the physical properties of the keys (modes, freq loss, const loss), listening points (access out position)
the pitch bend and spectral diffraction of the keys
the hardness and hysteresis of the mallets

2.
The mallets modes, frequency, loss and amplitude, as well as the force input and output (access in and out) have initial values, that are not dynamically modified in the patch, although the script allows it.

The script shows a number of mallet parameters: modes, frequency, loss, amplitude.

First question : MALLET.
=> Can anyone specify what those parameters correspond to, and if it makes sens to modify them dynamically? I don’t think modifying the modes, freq, loss and amplitude (I have no idea what ampli means in that case) of the mallets dynamically really makes sense. Am I right about this? They don’t depend on the force that is applied to the mallet I assume.
I am quite confused about the input and output force of the mallets. I cannot really represent my self what they are. Are they respectively the force exerted on the mallet and the force applied by the mallet to the key?

Second question: GAIN.
=> The resulting signal’s amplitude depends only on a gain parameter in the patch. But in the context of physical modeling, a realistic amplitude increase should be achieved, upstream, by increasing the speed of the mallet; This should then result, at least, in modifications of some the mallet’s properties, and the key response (and possibly input and output force), namely, the number of modes that are excited, and of course the gain (maybe the diffraction and pitch bend). Not to mention the size of the contact point (not relevant here I guess).

I have been advised not to change anything that should imply a real time modes computation, at least, when the signal is emitted continuously. But it seems to me that it’s a key parameter to render the energy increase. There are certainly ways to simulated that using different key instances.

Is there a way to actually simulate the speed of the mallet, and would that be a smarter way to change the gain, provided a corresponding method is implemented in the resonator? I guess we have an example of that type with the plucked string patch. Would it be the simplest way to control the instruments properties and the gain? (I would think of a ’set mode method). Is a similar method implemented in the object, or do we have to create transfer functions for that (which seems quite daunting to me)?
So: what parameters should be modified in priority, and what would be the smartest way to do it? Is the simple gain modification convincing?

I don’t think I have forgotten anything, but I might, as I am mentioning acoustic principles from the top of my head.

Thank you.

Coralie

August 12, 2016 at 18:48 #18786

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