Graduations for Response to Hard Bowing

[JacksonMaberry]

23 minutes ago, Michael_Molnar said:

Let me share briefly some of my findings for Cremonese cross arches. Most back plate cross arches can be fitted to a CC which is a tangential cosine and sine function. However, fewer top plate cross arches are true CC’s. They are often cosine and sine functions tangential to a connecting straight line of varying length. These can be found on some back plates too. On some Strad’s I found a compound sine (two sines) connecting tangentially to a straight line that runs to the cosine trough which are 4 functions.  My take away is that it is a complicated story. Calling these curves CC’s is not an accurate picture.

Pardon me if I drop off this thread. I have bigger fish to fry.
 

 

 

 

 

Thanks Mike, rest up. 

[Michael Darnton]

I think that most people would consider 350 year old tops to have quite a bit of untrackable distortion in a lot of different directions. It's a complex problem.

[Stephen Fine]

This has been a fascinating read...

Coming from the player's perspective, I think being able to push an instrument is an essential quality in a good instrument.

When trying decent instruments, they all turn "on" and make a nice sound easily enough.  Some may be too bright or too dull or whatever and that's somewhat to taste.  There's that boomy/hollow sound that I think we steer away from.  But what makes an excellent violin stand out is how you can continue to push and push and push and different things keep happening.  It is not my experience that there is "resistance".  Fine violins turn "on" just as easily, they just go much further when you ask them to do things with extremes of bow speed, pressure, and contact point.

And touching on the idea of selling your playing with body language, I'm not sure Heifetz is the ideal unless you can actually play like Heifetz.  

There was a fascinating psychological study done on a piano competition.  Hopefully my memory will serve:

Audiences of piano experts and non-experts were shown videos of competitors at a major piano competition.  They were shown videos with the sound muted and with the sound on.  Both the experts and non-experts were better able to predict the actual winner of the competition with the sound muted than with it on.

The audience is always deeply attuned to our body language.

[GoPractice]

22 hours ago, Marty Kasprzyk said:

Yes sometimes flat top guitars are built with back and top plates with these large radii. This produces arch heights of about 2 and 3 mm respectively.  A typical flat top guitar is roughly twice as wide as a violin so a violin would have around 1mm arch height on the top plate which would give negligible increase in a flat plate's stiffness and its various mode frequencies.

Interesting...

[Anders Buen]

The strings pull up and down an arch on "flat top" guitars. Easy to spot against the light.

The arching of any wooden instrument, archtop guitars, violins, or the like, will have a time varying arch shape following the relative humidity variations of the indoor air. The free plates may warp visibly.

The arch needs to be rather high before it has an effect on the modes. I have looked into this in relation to concrete floating floors where the drying process may cause the corners to rise while the concrete hardens. In a 5 x 5 m floor the central region needs to rise more than 20 cm (as far as I can remember) before it starts to affect the modes significantly. This is Soedel shell theory, probably known to Marty. 

Edited October 24, 2022 by Anders Buen
Correction of a spelling error

[Seán Ó Fearghail]

Can I ask I stupid question? How did they draw a curtate cycloid curve in the 1700’s? A ruler and a small disc with a hole in it? 

[Don Noon]

According to what I could find, the curtate cycloid was studied and named by Galileo in 1599, so they could either create one by the rolling disc method, or plotting the fairly simple math equation.  There is no positive proof that it was used by  the Cremonese violinmakers, though, other than the circumstantial evidence that some of the violin plates of some of the makers are kinda close.

[Seán Ó Fearghail]

1 hour ago, Don Noon said:

According to what I could find, the curtate cycloid was studied and named by Galileo in 1599, so they could either create one by the rolling disc method, or plotting the fairly simple math equation.  There is no positive proof that it was used by  the Cremonese violinmakers, though, other than the circumstantial evidence that some of the violin plates of some of the makers are kinda close.

Thanks so much Don… so… can I continue my naivety and ask… where is the biggest difference? Generally? 

[Marty Kasprzyk]

1 hour ago, Seán Ó Fearghail said:

Can I ask I stupid question? How did they draw a curtate cycloid curve in the 1700’s? A ruler and a small disc with a hole in it? 

Various arched curves have been free hand drawn long ago.

[JacksonMaberry]

37 minutes ago, Seán Ó Fearghail said:

Thanks so much Don… so… can I continue my naivety and ask… where is the biggest difference? Generally? 

Where is the biggest difference about what? 

[Seán Ó Fearghail]

59 minutes ago, JacksonMaberry said:

59 minutes ago, JacksonMaberry said:

Where is the biggest difference about what? 

From a CC… in comparison to a ‘cremonese ’arch.  is it where the curve turns upwards? A slower slope to the bottom of the lowest point. I do realise this is very hard to put into words. 

[JacksonMaberry]

7 minutes ago, Seán Ó Fearghail said:

 

Ah ok, yes something better served by overlays than sentences.

 

[GoPractice]

2 hours ago, Seán Ó Fearghail said:

Thanks so much Don… so… can I continue my naivety and ask… where is the biggest difference? Generally? 

Data sets are complicated.

I am trying with great effort to get onboard with several concepts, ideas, technique. I am slowly migrating towards roasting woods after the purchase of European woods and had an option between fumigation and baking. The purchase was nearly twenty years ago and my experience is towards the positive, as a player. Baking is better than poisoning. Historically, how will that work out? As for my life now, there are results, and as a player living now and not in the future, baking and humidity cycling is an option.  

Many of us are not naive, but lazy. If it were possible, I might CT scan every old instrument.

If there are visible distortions towards the more extreme "S" shape, then perhaps the arch is collapsing inward. If some owners loved the English style wire "e" string. then perhaps the distortion is towards the treble side.

We understand that there are structurally sound shapes. Some are more structurally and simultaneously dynamic than others. As much as I truly admire professors(i) Noon, Kasperzyk and Buen, it would be difficult to impose upon them a data set that were cast upon thousands of instruments, of instruments hundreds of years old.

But intuitively, what would happen to one's ribcage if a small child were to sit on your chest for the hundreds of years?     

  

 

 

 

[Don Noon]

18 minutes ago, GoPractice said:

Data sets are complicated.

We understand that there are structurally sound shapes. Some are more structurally and simultaneously dynamic than others. As much as I truly admire professors(i) Noon, Kasperzyk and Buen, it would be difficult to impose upon them a data set that were cast upon thousands of instruments, of instruments hundreds of years old.

There are shapes far more structurally efficient than the usual violin arching... but I'd bet they don't sound good.  What we have is a shape (and thickness, wood properties, etc.) that has evolved to sound "good" and last an acceptable amount of time before creeping an unacceptable amount.

A data set of shapes won't do much good without the associated graduations and wood properties... and some way to quantify (or at least qualify) the performance that results.  I have no hope of extracting useful information that way any time soon, if ever.

IMO experience in making is the key... trying things, and finding out what does what.  And getting experience around great instruments and players to know what the goals are.

[Dennis J]

To me it seems ridiculous to talk about arching in an abstract way, assigning geometric curves to cross-arch shapes. The nature of those compound curves vary from each other along the length of the violin. That is obvious.

The fact is those curves can be constructed using  height and width parameters along with the position of a calculated inflection point as I have shown. They are a part of a complex upper convex and lower concave shape which forms a typical violin shape.

And the only way to plan any arching is to draw those chosen cross-arches at chosen locations. And the only way to carry out that plan in the making process is to make templates based on those drawings.

[GoPractice]

25 minutes ago, Dennis J said:

 ( ... )

And the only way to plan any arching is to draw those chosen cross-arches at chosen locations. And the only way to carry out that plan in the making process is to make templates based on those drawings.

Is it? What is your favored c-bout width, if that were to be a starting point? In my pea sized mind, aside from the whole of the geometry of the most recent decades and modern strings and techniques, the ideal perhaps desired sound is different from how one might play the instrument. From flat arches to the sadly descriptive "chicken breast" that is, I might assume, where we have arrived. The arch was and is new.

If the discussion is exclusive to the violin, I have thoughts. But to include the viola and the cello would be interesting.

I have never bothered to analyze the lower instruments.

[GoPractice]

Sorry. Too aggressive? Things are pretty bad.

[JacksonMaberry]

43 minutes ago, Dennis J said:

To me it seems ridiculous to talk about arching in an abstract way, assigning geometric curves to cross-arch shapes. The nature of those compound curves vary from each other along the length of the violin. That is obvious.

The fact is those curves can be constructed using  height and width parameters along with the position of a calculated inflection point as I have shown. They are a part of a complex upper convex and lower concave shape which forms a typical violin shape.

And the only way to plan any arching is to draw those chosen cross-arches at chosen locations. And the only way to carry out that plan in the making process is to make templates based on those drawings.

I could stay on board until the sentence I italicized. Arching templates are totally fine, but they are not at all necessary and it cannot be proved that they were ever in use in old Cremona. The fact that none of my most successful friends and clients in the trade use cross arch templates shows rather the opposite. 

[GoPractice]

Drivers these days suck. SUVs suck. 

48 minutes ago, Don Noon said:

 ( ... )

A data set of shapes won't do much good without the associated graduations and wood properties... and some way to quantify (or at least qualify) the performance that results.  I have no hope of extracting useful information that way any time soon, if ever.

IMO experience in making is the key... trying things, and finding out what does what.  And getting experience around great instruments and players to know what the goals are.

As scientists and engineers, that becomes our role. Hopefully one of my nephews would care so much... In the current workforce, we wear different hats. I have spent 10s of thousands of dollars to impress upon my nephew ( singular ) how tone and playability matters. I was a scientist ( at least that my description on the business card, ) but as an engineer I feel as though someone sold us out.

So you, Manfio, many have been such excellent examples. Bowed instruments have truly improved since the millennia, but unfortunately, the support for younger. the youth set... have not the offered the opportunities of the past, not long ago. 

Could data be deeper? Could experiences be more descriptive? 

I am not complaining. We might be the at the best we have ever been. But is that currently enough?

[GoPractice]

Sorry again. Whining....

Interesting instruments make for interesting people. Those who might understand, further the art.

I have to teach based on the instruments that "do things." If they sound like a 1717 Strad and nothing else, good for them. But the internalized thought is that a student, player, artist, maker, must be flexible.

I never mention God, but even Maestro Burgess suggested that he's created a variety of instruments, those that behave one way and perhaps another. My God...

In my shallow, little petty, non- consequential mind, the arching matters, as do strings and for those who make adjustments to that little weird stick that holds up the top. 

Super stiff tops sound one dimensional. Softer tops distort. We can accelerate that experience by adding moisture.

[Dennis J]

Just to say that nobody uses them doesn't mean much because they have never bothered to make a set of them because they don't know how to. I'm talking about planning an arching shape using the long arch and outline shape measurements. The basic shape of that arching can be varied to some extent depending on what is desired. The most obvious variable available is the width of the convex upper portion.

That sort of precise control creates planned options which might influence the performance of the instrument. Hard to do with any other approach I would say.

 

 

 

[JacksonMaberry]

44 minutes ago, Dennis J said:

Just to say that nobody uses them doesn't mean much because they have never bothered to make a set of them because they don't know how to. I'm talking about planning an arching shape using the long arch and outline shape measurements. The basic shape of that arching can be varied to some extent depending on what is desired. The most obvious variable available is the width of the convex upper portion.

That sort of precise control creates planned options which might influence the performance of the instrument. Hard to do with any other approach I would say.

 

 

 

Dennis, before we get into another fight, can you help us understand why we're supposed to take your word for all of this instead of listening to the people that make a living doing this and who have made instruments we have actually seen, heard, and like? I genuinely think it's great that you have big ideas, but until you put your money where your mouth is, they're just the whims of a dilettante. 

[Dennis J]

I've never talked about outcomes just methodology. I'm not questioning the skill or knowledge of makers.

I've pretty well confined my posts to arching and tools. I'm not even recommending any particular sort of arching just one that fits a predetermined, deliberate choice. If you can do that with accuracy you can assess what the outcomes might be and draw some conclusions.

[Don Noon]

3 hours ago, Dennis J said:

And the only way to plan any arching is to draw those chosen cross-arches at chosen locations. And the only way to carry out that plan in the making process is to make templates based on those drawings.

There are many ways to plan and carry out arching, and I've tried most of them.  From the sculptor method of removing the wood that doesn't fit my concept of an arch, to using templates from a known Strad, to using a set of arc templates just for key zones, and finally to using modelling software, splines, and lofting to create a surface for CNC.  I haven't tried cycloids, though, as I am a non-believer.

They all can work fine if you have a good arching idea in mind. 

I have to also admit that I've seen one amateur's work with godawful non-Cremonese arching where he sometimes gets one to sound very good.