Jump to content
Maestronet Forums

Scientific investigations of Stradivarius violins--an updated review article


Bruce Tai
 Share

Recommended Posts

  • Replies 564
  • Created
  • Last Reply

Top Posters In This Topic

1 hour ago, Marty Kasprzyk said:

The simplest and first combination I tried was a flat top with a flat back (0,0). 

That was the combination on my very first fiddle too (the original snakefiddle).  It had tons of midrange and sounded not too much like a good violin.  And the top caved in and split.  And it needed a wasp-waist outline to give bow clearance.

Thus showing why violins are shaped the way they are and sound the way they do, and why I didn't try to keep going with flat plates.

 

Link to comment
Share on other sites

17 hours ago, Anders Buen said:

White light has a very short coherence length. It is of the same size as the wavelength of orange light. Very thin coatings on optics make them appear greenish, or yellowish. Some violet some orange. The thickness of the layer determine the colours. Light reflected from oil on water give similar effects. I think these layers are 1/4 of a wavelength thick.

varnish is much thicker. So the coherence is gone before the direct light meet the reflected. No colours filtering appear from this.

Particles in the varnish or elements on the surfaces start to spread light from wavelength/4, just as in acoustic diffraction. From about wavelength size they start to reflect light efficiently.

i think the nomenclature you use here chatoyance, dicroism belong to different fields in physics than describing varnished wooden surfaces. 

I think of chattoyance as dancing light reflections as we or the wood moves from side to side. 

The colour effect I want to see is like a sunset, yellow, orange and red. A simple thick coating of red is not what I want to see on a violin. The coatings I use are microns thick. Can the red be enhanced with very thin coatings? 

Recently Roger Hargrave posted here to say that the red in classical Cremonese varnish came from cooking the colophony and not from pigments. But Échard claims to have found 2 different types of Madder plus Cochineal in Stradivari's varnish.

Link to comment
Share on other sites

39 minutes ago, sospiri said:

So when we're standing on the shoulders of giants, do we have to pick n choose da bestest giant?

I think so. Da bestest fiddle-maker at the local county fair and chili-cookoff may not always be the bestest person to get higher learning from.

Link to comment
Share on other sites

Marty, what you did is close to scientific. You tried and got result but unfortunately you stopped. I also started but never stopped. I'm still searching and ask myself many questions. One of them was as written above "why arching shape". What secret is technical hidden in the complex arching shape. Complex as it is I have found a very simple solution with quite a number of quality hidden in the shape. What those quality mean to function is still part of my research. Unfortunately no one of you seem to be interested. I don't claim anything but let you all know what I found out. Nothing more nothing less.

Enclosed some sound spectra of the open played G-string. Of course it is difficult comparing what your result may become since we have different equipment and room conditions. However, it could bring you to some understanding how your instrument function. Try it and consider. The result of my spectra is after adjusting the dynamic behavior on the violin body by polishing the varnish. Of course there may be some differences depending on my bowing capacity and the speed of the bow and pressure. Try it your self.

REC 20210420.docx

Link to comment
Share on other sites

4 hours ago, sospiri said:

I think of chattoyance as dancing light reflections as we or the wood moves from side to side. 

I have found and seen tiger eye stone, "stonified, or fozzilized wood" with its mesmerizing light and color mixes. I prefer simplicity, and she shine one get, and not shine, is simply reflections, or no reflections and something in between. There is nothing special about it, except techniques can be used to enhance it. 

4 hours ago, sospiri said:

The colour effect I want to see is like a sunset, yellow, orange and red. A simple thick coating of red is not what I want to see on a violin. The coatings I use are microns thick. Can the red be enhanced with very thin coatings? 

I do not know. I do not varnish following violin making traditions, although it does have some similarities. Hardanger fiddles are ink decorated on the plates and ribs. Effects you may want on violin maple parts does not work well with decorations. Decorations and wood figure "competes". The wood is therefor often plainer and lighter in colour. We also water color the plates before adding the decorations, seal it with ground varnish, some colourized varnish and then some coats clear more "polisheable" layers. 
One learn some "rules". The color will always brighten with the varnish coats, besides the color varnish. My speciality if the polishing. Very early I learnt to make them glass clear with right abrasives using my fingers and palm at the end. Later I learnt a pro furniture restorer also did that. Not all like that shiny surface, but i think my teacher grandpa did. I did it better than him on my first instrument at 13. The reflective surface will also determine how much light will penetrate, without being spread or diffused. A very reflective surface will also not spread light. Some light is lost but more at more direct angles enters the varnish layer. 

To your question: I do not know if a thin layer enhances red or not. But I believe it does not, if I should guess. Much of the "secrecy", I think, with varnish is what you do with the "white instrument" and grounding.

4 hours ago, sospiri said:

Recently Roger Hargrave posted here to say that the red in classical Cremonese varnish came from cooking the colophony and not from pigments. But Échard claims to have found 2 different types of Madder plus Cochineal in Stradivari's varnish.

Interesting, but is is useless information for my work, as I do not try to copy or follow Cremonese violin making tradition. I do not even think that their varnish was particularly good, by what I see and read. Prone to chipping e.g. However, I do admire the violin makers who do make instruments that look like old instruments. It is some kind of artwork. And it certainly looks very good, sometimes. The use good looking wood too. 
I have also seen top modern makers who do not antique and thought that I can do better than this. I have also been impressed by plain instruments. I have seen instruments by a varnish expert that looked pretty dull in room light, with faults in the arching, in addition. We all have a development going, in some form, and everything is not successful all the time. I respect that. 

Link to comment
Share on other sites

2 hours ago, reguz said:

Marty, what you did is close to scientific. You tried and got result but unfortunately you stopped. I also started but never stopped. I'm still searching and ask myself many questions. One of them was as written above "why arching shape". What secret is technical hidden in the complex arching shape. Complex as it is I have found a very simple solution with quite a number of quality hidden in the shape. What those quality mean to function is still part of my research. Unfortunately no one of you seem to be interested. I don't claim anything but let you all know what I found out. Nothing more nothing less.

Enclosed some sound spectra of the open played G-string. Of course it is difficult comparing what your result may become since we have different equipment and room conditions. However, it could bring you to some understanding how your instrument function. Try it and consider. The result of my spectra is after adjusting the dynamic behavior on the violin body by polishing the varnish. Of course there may be some differences depending on my bowing capacity and the speed of the bow and pressure. Try it your self.

REC 20210420.docx 1.46 MB · 4 downloads

I think you would be surprised how much these spectrum tests have  been done by people on this forum, including me, thousands of times.

It's fun and interesting but quite useless if not conducted in a lab with the exact same setup and a good player that can play repeatedly. One should actually remove the player from the equation and find some other method to mecanically play the strings.

If you start using a real time FFT analyzer as I do, you will discover how easy it's to deceive yourself. The slightest change in playing, movement and angel towards the mic, will have greater impact on the spectrum than anything else you have changed on the violin.

This you will see in a realtime FFT analyzer.

Sorry for the long post...

Link to comment
Share on other sites

Chattoyant maple doesn't need any treatment to make the light dance. Maybe spruce does.

I understand about hand polishing techniques and I use them too. I believe thin layers are necessary to retain the natural tone and volume of the unvarnished wood and hopefully enhance the tone with the right kind of damping.

I also want to avoid the problem of chipping and scratching. I would like to do a thread about this soon and discuss some of the newer research.

Link to comment
Share on other sites

58 minutes ago, sospiri said:

I understand about hand polishing techniques and I use them too. I believe thin layers are necessary to retain the natural tone and volume of the unvarnished wood and hopefully enhance the tone with the right kind of damping.

Do you stop or continue after the «window washing» sqeeking noise appear? Which time do you think is most important, pre or post noise?

The varnish on my fathers uncle maker fiddles is very thin. However, holding the instrument for playing probably dominates over the damping from the varnish. 

Link to comment
Share on other sites

9 hours ago, sospiri said:

So you like the sound, but trained players don't? 

As Don Noon and others have often pointed out-if it doesn't sound exactly like what most players are used to then it is unacceptable. People often don't like change. 

I've changed everything possible from a typical violin (except for string length, spacing, bridge curvature etc.)different woods and design. It's hardly a surprise that they don't sound typical after a lot of effort trying to do so and this was quite discouraging.  However a young player I recently met said:  "This is great!  I've finally found something different from all the rest."

Too bad he's broke.

 

Link to comment
Share on other sites

9 hours ago, Don Noon said:

That was the combination on my very first fiddle too (the original snakefiddle).  It had tons of midrange and sounded not too much like a good violin.  And the top caved in and split.  And it needed a wasp-waist outline to give bow clearance.

Thus showing why violins are shaped the way they are and sound the way they do, and why I didn't try to keep going with flat plates.

 

When something breaks it means either the part isn't strong enough or that the applied load is too large.  Early string instruments often had flat top plates and they had low bridges with a shallow curvature.  These were suitable for playing multiple strings  at one time for chords but as music evolved there was a demand for single note playing.  This required higher bridges with more curvature which enabled a single string to be played. Narrower C bout widths helped give more bow clearance.

The higher bridges made the string angle over the bridge more acute which increased the downward load on the the top plate.  The flat top plates were no longer adequately strong so makers started to use stronger and stiffer arched plates to better resist this string downward  load.  Thus the sound character of the instrument then followed the increased strength and stiffness requirement.  Arching increased the stiffness with little increase in mass so the result was higher resonance frequencies resulting in a brighter but less mellow sound.

This was obviously successful and all our violins, violas, cellos and basses now use arched top plates with their sound character.

But an alternate path of reducing string loading could have been chosen centuries ago.  My instruments use a shallow string angle (~168 degrees instead of about 158 degrees) which decreases the downward string load on the top plate by about a half.  I've also adapted the ancient (12th century?) Welsh crwth instrument's design which uses only one  bridge foot  resting on the top flat plate.  The other foot rests on the sound post which goes through a hole in the top plate so this foot's force goes to the back plate rather than the top. This obviously also reduces the string load by a half so the total downward load is only about a quarter of a normal arched plate instrument.  

The tailpiece is also integrated with the fingerboard so the string tension load is not applied to the instrument body. This eliminates the longitudinal load on the top plate which is a contributing factor in conventional arched plate buckling. The end result is that a flat plate top can survive.

Anyway, I'm following the road not taken.

  

 

Link to comment
Share on other sites

13 hours ago, sospiri said:

Recently Roger Hargrave posted here to say that the red in classical Cremonese varnish came from cooking the colophony and not from pigments. But Échard claims to have found 2 different types of Madder plus Cochineal in Stradivari's varnish.

It is interesting that Roger Hargrave should think this way.

To my knowledge, Michelman was the first to point out the possibility that the oleoresin medium could be colored. He proposed metal rosinates. 

Surely many studies have found pigments in Stradivari's varnish. But they seem to be too sparse to give strong tinting strength. The medium may also be colored, but we don't have exact measurements of their spectral properties. 

Joe Robson has interesting theories of how certain pigments could blend into the medium to become almost invisible under the microscope. 

As I wrote in my review, the coloring issue is still unresolved. 

Link to comment
Share on other sites

8 hours ago, Peter K-G said:

I think you would be surprised how much these spectrum tests have  been done by people on this forum, including me, thousands of times.

It's fun and interesting but quite useless if not conducted in a lab with the exact same setup and a good player that can play repeatedly. One should actually remove the player from the equation and find some other method to mecanically play the strings.

If you start using a real time FFT analyzer as I do, you will discover how easy it's to deceive yourself. The slightest change in playing, movement and angel towards the mic, will have greater impact on the spectrum than anything else you have changed on the violin.

This you will see in a realtime FFT analyzer.

Sorry for the long post...

Well said. The real-time FFT spectra of a sustained note can fluctuate a lot. But it sounds stable to our years. Auditory illusion? I wonder if top soloists can produce a more stable spectrum or may be a more interesting fluctuation pattern. The bowing action is quite mysterious, and so are the top French bows. Did the French conduct secret wood treatments?  

Link to comment
Share on other sites

On 4/19/2021 at 3:24 PM, David Burgess said:

I don't know. Refer back to what I have posted above. I did not own it at the time, and don't recall ever having spoken with Menuhin.

A little history on that particular violin, according to the Smithsonian website:

https://americanhistory.si.edu/collections/search/object/nmah_605484

Wow.   Impressive.  How many comment ID's do you have at the Smit?  :huh:  outtahere.gif..gif.12a6f31e6ce7701f2afafd5c1d33ca32.gif

Humor aside, it would be very, very cool to have that violin on display.  :)

Link to comment
Share on other sites

17 hours ago, sospiri said:

Recently Roger Hargrave posted here to say that the red in classical Cremonese varnish came from cooking the colophony and not from pigments. But Échard claims to have found 2 different types of Madder plus Cochineal in Stradivari's varnish.

Not his claim at all! 

Previously I was accused of not reading.. If Wikipedia is shady, Roger's Making a Double Bass is one of the best reading.

My wife had it printed in color and laminated all pages (180 p) in plastic and binded into a book for me, to have in my workshop.

Quote from the book:

These limitations are further frustrated by the fact that pigments were undoubtedly added to some, if not all varnishes. Clearly, these pigments will have varied considerably in both quality and type. They may have changed or faded and/or the medium in which they were locked may have altered their properties markedly. In fact, added colouring matter may have altered the configuration of the varnish itself. For example, lake colours, especially Madder lakes, seem to promote Craquelure.....

 

 

Link to comment
Share on other sites

13 hours ago, Anders Buen said:

Do you stop or continue after the «window washing» sqeeking noise appear? Which time do you think is most important, pre or post noise?

The varnish on my fathers uncle maker fiddles is very thin. However, holding the instrument for playing probably dominates over the damping from the varnish. 

Sorry Anders, I don't understand your questions.

But I'm sure that too much varnish is bad for the sound.

Link to comment
Share on other sites

2 hours ago, Peter K-G said:

Not his claim at all! 

Previously I was accused of not reading.. If Wikipedia is shady, Roger's Making a Double Bass is one of the best reading.

My wife had it printed in color and laminated all pages (180 p) in plastic and binded into a book for me, to have in my workshop.

Quote from the book:

These limitations are further frustrated by the fact that pigments were undoubtedly added to some, if not all varnishes. Clearly, these pigments will have varied considerably in both quality and type. They may have changed or faded and/or the medium in which they were locked may have altered their properties markedly. In fact, added colouring matter may have altered the configuration of the varnish itself. For example, lake colours, especially Madder lakes, seem to promote Craquelure.....

 

 

Yes I've read it. Several times. I don't use any of his methods. They are all extremely complicated, expensive and time consuming. I use much simpler methods. 

But I thought he had a new idea he wanted to share?

Link to comment
Share on other sites

6 hours ago, Bruce Tai said:

It is interesting that Roger Hargrave should think this way.

To my knowledge, Michelman was the first to point out the possibility that the oleoresin medium could be colored. He proposed metal rosinates. 

Surely many studies have found pigments in Stradivari's varnish. But they seem to be too sparse to give strong tinting strength. The medium may also be colored, but we don't have exact measurements of their spectral properties. 

Joe Robson has interesting theories of how certain pigments could blend into the medium to become almost invisible under the microscope. 

As I wrote in my review, the coloring issue is still unresolved. 

I would be interested to learn about Joe's ideas. 

Link to comment
Share on other sites

11 hours ago, Marty Kasprzyk said:

As Don Noon and others have often pointed out-if it doesn't sound exactly like what most players are used to then it is unacceptable. People often don't like change. 

I've changed everything possible from a typical violin (except for string length, spacing, bridge curvature etc.)different woods and design. It's hardly a surprise that they don't sound typical after a lot of effort trying to do so and this was quite discouraging.  However a young player I recently met said:  "This is great!  I've finally found something different from all the rest."

Too bad he's broke.

 

Can he give us a demo? 

Link to comment
Share on other sites

20 hours ago, sospiri said:

Recently Roger Hargrave posted here to say that the red in classical Cremonese varnish came from cooking the colophony and not from pigments. But Échard claims to have found 2 different types of Madder plus Cochineal in Stradivari's varnish.

 

3 hours ago, Peter K-G said:

Not his claim at all!

Roger's Making a Double Bass....

Quote from the book:

These limitations are further frustrated by the fact that pigments were undoubtedly added to some, if not all varnishes. Clearly, these pigments will have varied considerably in both quality and type. They may have changed or faded and/or the medium in which they were locked may have altered their properties markedly. In fact, added colouring matter may have altered the configuration of the varnish itself. For example, lake colours, especially Madder lakes, seem to promote Craquelure.....

 

 

 

28 minutes ago, sospiri said:

Yes I've read it. Several times. I don't use any of his methods. They are all extremely complicated, expensive and time consuming. I use much simpler methods. 

But I thought he had a new idea he wanted to share?

How skillfully you avoided that...

Making a Double Bass book is not about reading, it's about doing!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.




×
×
  • Create New...