William Fry Internal Scraping Method

[David Burgess]

1 hour ago, Don Noon said:

Not very convincing.

Is too!

[Fiddlemaker5224]

Fry's method does not work, don't waste years trying to make it work.

[edi malinaric]

4 hours ago, notsodeepblue said:

Does anyone happen to know what "Fry Scraping" looks like?

I am curious if the image below fits the bill, or if it is another form of vandalism entirely... 

It isn't obvious from the image, but below the obvious scarification marks are others that run with the grain and that have somewhat softer edges - as if sanded - which had me wondering.

 

Back to medical class me boyo - don't you recognise a mild case of itchy soundpostitis?

cheers edi

[notsodeepblue]

35 minutes ago, edi malinaric said:

...a mild case...

...it get's worse?!

[violguy]

I'm surprised no mention has been made about the effects of erotic breathing as it could measurably effect the tonal characteristics of violins and other stringed instruments. I will leave the set-up for these experiments to those who have much more experience and inclination than I.

 

[David Burgess]

22 hours ago, edi malinaric said:

Back to medical class me boyo - don't you recognise a mild case of itchy soundpostitis?

cheers edi

That''s pretty good, and much more presentable than scratching itchy hemorrhoids.  Not that they couldn't  have many things in common.

[Lars Silen]

On 3/9/2019 at 8:36 PM, Fiddlemaker5224 said:

Fry's method does not work, don't waste years trying to make it work.

Should one understand this in the following way?

- All graduations are equal. No need to put any effort to get graduations right because graduations do not influence the sound!
- The edges of the f-holes will always radiate high frequency sound in an optimal manner. The thickness of the f-hole edges do not influence the sound of a violin!
- If a violin sounds bad the reason for the bad sound is found only in the wood/varnish used!
- The form and dimension of the bass bar has been selected only for aesthetic  reasons!

-------  end of intro -----

I think there are many builders that resort to re graduating an instrument that doesn't work even after lot's of time has been used for proper set up. This would indicate that the first case above is false. Historically it is known that a large number of top quality instruments have been re graduated in former times.

My own experience is that it is fairly easy to adjust the f-holes to get a "better" more interesting sound and I think I understand what my adjustments do to the working instrument. The second point thus looks false and the exact thickness and form of the f-hole areas in relation to the top in general is important.

Re graduation at least occasionally seems to produce some improvement. I would interpret this to mean that the sound isn't in the wood but in a combination of wood and proper "tuning" of the hole instrument. There are many different tuning methods both while building the instrument and methods to fix problems afterwards. To work any of those methods require time to learn and much experience.

I think the point about the bass bar probably doesn't need any comment.

My personal view is that Fry tried to use a method that at least for a physicist like me looks sound. If you have an instrument that is a coupled collection of oscillators and you want to improve the sound then you should try to tune important oscillators in order to improve the sound. The problem is of course to know where to scrape/sand and my feeling is that Fry didn't necessarily have the necessary experience meaning that adjustments were partly  random. I am sure Fry didn't have a complete picture of how a violin works on a low level which makes it difficult  to do rational changes.  Fry's tools were also very primitive which means only fairly restricted areas were available for adjustment.

A final problem is of course that it is very easy to fool oneself when doing adjustments. We tend to hear what we want to hear and the room where we do adjustments will influence the sound we hear in a major way.

 

[David Burgess]

26 minutes ago, Lars Silen said:

A final problem is of course that it is very easy to fool oneself when doing adjustments. We tend to hear what we want to hear and the room where we do adjustments will influence the sound we hear in a major way.

Yup. One of my biggest challenges has been avoiding the various ways of fooling one's self. If anyone thinks they have that perfected, I would suggest doing a more thorough investigation.

[Julian Cossmann Cooke]

1 hour ago, David Burgess said:

That''s pretty good, and much more presentable than scratching itchy hemorrhoids.  Not that they couldn't  have many things in common.

It's all about the tool you use, don't you know David?

[David Beard]

 

Lars---

 

The method is literally scratching around the edges of the matter.

Regardless of any effects that may or may not be produced in any such session of tinkering, the process isn't intrinsic enough to be a core factor in what is good with classical instrument.  When you tune strings, they don't stay tuned for centuries.  The scale of adjustment with these scratching will make them ephemeral.  

As you've noted, classical instruments were and remain prized before and after long strings of significant alterations.  For various instruments these have included some or all of:

* Neck replacement and realignment

* FB lengthening and stiffening and mass change

* String under many different tension levels, and variations of tuning.

* Bass replacements with change of shape, size, length, weight, stiffness

* Post and bridge changes

* String angle, beidge, nut, and saddle changes. Even stop length alteration.

* Conversions from one instrument type to another. i.e. Gamba to cello, etc.

* Major size reductions.  Large violas and celli to smaller for example.

* Significant varnish losses and additions 

* Patches from soundpost to breast patches.

* Interior sizings and various applications

* Even plate regraduations.

 

When not done horribly poorly, none of these significant changes either create the virtues of classical instruments, nor take it away.

All this suggests the core virtues of good instruments are VERY robust and intrinsic.  

A little bit of scritch scratch tickling and pricking doesn't have the kind of permance seen by the core virtues of good instruments.  Bridge and post work can greatly change the playing performance of an instrument, obstructing or freeing it's potentials.  But know claims that post or bridge work changes the core qualities of an instrument.

Only the basic corpus shape and structure, and the integrity of materials and work of a persistence that tracks with core virtues of good instruments, so look to these first to understand, and only to the most essential and persistent aspects of instrument.

 

In your intro, you dismiss the notion that graduation might not actually matter much to the core qualities of an instrument.  However, we have many pionts of fact that such exactly this:

* neither players or the market make a big distinct either pro or con about instruments that have or haven't been regraduated

* among cottage industry traditions there are instruments that take a very coarse and rough approach to interior surfacing and thickness.  i.e. Rough gouged.  But as instruments, these aren't really better or worse than their smooth interior and perhaps graduated conterparts

* CT scans and maps of plates from classical making show more a random drift of thickness around a simple diaphragm thickness, rather than any cpnsistent patterns of deliberate plate graduations.

 

These things suggest that precise specific graduations of plates maybe much less useful than many modern makers presume and believe.

********************

We can look across collections of CT scans and thickness maps to see what might emerge as consistent across many examples.  The following be noted:

* The extra central back masses have maximum thickness somewhat above the bridge line. These thickness taper away and then blend into the general diaphragm thickness.

*Between make and patching, thickness under the post is on the thicker side of drifting diaphragm thickness to a non-random extent.

*The diaphragm thickness tends to give way and blend into extra thickness into the edgea.  Particularly there is often extra thickness left in the top's cBout area outside the soundholes.

*Some area of higher plate mobility show a somewhat greater chance of being on the thin side of the plate drift range. These areas include between the upper soundhole eyes, along the upper and lower main bout lines, and in the flanks of these bouts.  These tends also vary some by maker, suggesting intent.  So, while fallsing sort overall plate gruaduation plans, you can says some small specific things, like Strad mostly avoided leaving the area between the upper eyes overly thick.

* The overall diaphragm thickness tends to basically be in the range of 2/3 the edge height.  The random drift in this thickness is usually greater than +/- .1mm and often as much as +/- .3mm

**********

 

You also drew the common analogy to collection of oscillators.

However, I want to point out that this analogy is highly limited.   The violin is a driven system, and that is a big difference.

As we all know, resonances can be tuned.  This tuning has two specific aspects, the frequency and the Q.  All such resonances will actually respond to a little range of frequencies.  The 'frequency' of the resonance will then be taken as the center of that range of response, or as the point of strongest response.  The Q then is a measure of the breadth of the resonance response.  The physics of resonances tells us that a low Q resonance will respond more weakly, buy to a broader range of frequencies.  A high Q resonance will respond more strongly, but only around a narrower range of frequencies around the central frequency of the resonance.

Consider a marimba. This fits the collection of oscillators perfectly. A marimba consists actually of two collections of oscillators.  The first collection consists of a separatw wooden key for each pitch of the instrument's range. 

Each key is carefully shaped to pruduce a high Q resonance of the desired frquency when struck.  A long skinny shape helps give a higher Q.  The high Q means the random energy from a physical strike will tend to fall into a cleanly specificly pitched resonance. Exactly what we want.

Each key is then paired with another oscillator from a collection of air column tubes.  These also are tuned for specific high Q resonances.  

But why bother with this second collection of oscillators?   The reason gets into issues of impedance and coupling of resonances.  The wooden keys are highe impendance, and relatively low surface area.  These things mean they won't couple that well with the air, and the vibrations need to radiate into the air for us to hear them.

However, the air columns are made with somewhat wide mouths, and their impedance matches the surrounding air.  Both these things improve their coupling to the air, and therefore the radiance of musical signal.

 

But the violin is different.  The strings are high Q, and stopped to the exact length to create a desired musical pitch signal, rich with overtones.  But the stop can and is changed rapidly and variable to create musical signal.

The body then has the job of coupling and radiating these signals into the air. But a violin body does not offer a dedicate high Q resonator couple to each pitch of the scale.  Nor are pitches in between scale tones off limits.  So the 'oscilators' of a violin body are faced with a different kind of challenge then the dedicated individual oscilators of a marimba.  Also, the 'oscilators' of a violin consist of various modes of components of a violin, sometimes indivially and sometimes coupled with other components.  And component with mass potential can participate in some modes.  

But the mode oscilators of a violin need  collectively to respond to every possible frequency from the pitch of the lowest string to the upper limit of our senses.

This is assisted by broader blended responses of the many modal oscillators of the overall system.  And broader more blended response for a driven system mean lower Qs.

 

This is not currently well appreciated by many parts of our community.   

 

A driven system where overall radiance and even response acrosas the musical range requires that most individual supporting oscilators veer toward lower Qs contradicts the notion that very precise tunings of resonances matters, except where directly part of the stringing system.

 

 

More to say gotta go now.

High Q is over rated for violins.

 

[Don Noon]

1 hour ago, David Beard said:

....broader more blended response for a driven system mean lower Qs.

This is not currently well appreciated by many parts of our community.   

High Q is over rated for violins.

If a violinist was a constant force driver, this would be true, and looking at the response from a constant force function would apply.  But I think that energy, not just force, is of critical importance to a player.  THAT I think has been overlooked by the techno types, and makes Q of much more importance.

I generally don't read gigantically long posts, but the final line stood out.

[David Beard]

Hi Don,

If I'm not confused, you're focus more about higher Q in terms of intrinsic material dampening of energy.  So a raw material that in a simple shape doesn't eat up energy put into it.  So you want a highly eleastic material.

I agree with this priority. Perhaps I give it a less exreme priority, but I agree it's highly important.

But the concept of Q in resonances also embraces issues of shape.  A shape can lead to a low Q resonance with broad response, even if the material isn't significantly dampening.

In such cases, the resonance losses energy by returning to the surrround media, where perhaps some other resonance or radiance can capture it.

I doubt our opinions present any real conflict on these points?

 

[Andreas Preuss]

On August 13, 30 Heisei at 11:15 PM, dpappas said:

I just read a book called "Cremona Violins" written about William "Jack" Fry.  It contained some interesting history, some physics, and many dubious claims.  The thesis of the book was that the cremonese masters must have adjusted violin thickness on the inside after completing the violin (varnish, etc).

To keep the thread from spiraling out of control, I wanted to ask specifically if anyone has tried this method.  In the book, many grand claims of graduation measurements were made, and the author (not Fry) asserted that Fry saw the same internal scraping tool at the museum in Cremona.  You too, apparently, can take an old german violin and produce a del gesu in sound (sarcasm).

As a fellow scientist, I found Fry's claims to be unscientific, but I was curious from makers on MN, does anyone actually adjust sound on a finished instrument this way, or does one focus more on traditional setup at that point.

For what it's worth, I'm completely happy with my violin, and I'm not expecting to suddenly transform it with a coat hanger and some sandpaper.

Pure nonsense.

[dpappas]

39 minutes ago, Andreas Preuss said:

Pure nonsense.

That’s what I figured when I started this thread, but I wanted confirmation.  

[edi malinaric]

5 hours ago, dpappas said:

That’s what I figured when I started this thread, but I wanted confirmation.  

Hi Andreas/dpappas - don't give up so easily - we're only on page 8 :-)

However just to put some values to scratching - removing 0.1mm from plate thickness in a violin  should lower the stiffness at that spot by about 6 - 8% . How that affects the response of the plate as a whole I don't know - maybe Don could chime in.

cheers edi

[Lars Silen]

9 hours ago, David Beard said:

When not done horribly poorly, none of these significant changes either create the virtues of classical instruments, nor take it away.

Please notice that my intro was formulates as an "antithesis". It is absolutely obvious that graduation of the top/bottom plates influences the sound. If we go from no graduation to the graduation of a very high end instrument it is obvious that different graduations will produce more or less different timbres in the final instrument. The same can be said about the bass bar, rib thickness etc.

The problem is to learn what changes will produce a desired tonal change in the instrument being worked on. I am sure skilled builders that modified strads/guarnieries had a good reason for the changes ... no sane builder/repairer does changes to an instrument only for the sake of making a change.

I see

 

11 hours ago, David Beard said:

A little bit of scritch scratch tickling and pricking doesn't have the kind of permance seen by the core virtues of good instruments.  Bridge and post work can greatly change the playing performance of an instrument, obstructing or freeing it's potentials.  But know claims that post or bridge work changes the core qualities of an instrument.

This is true when looking at Fry's video. On the other hand using proper tools you can do much more than "scratch ticking". Actually you can do the same kinds of adjustments as the builder does to the final graduation (scraping taking off 1/100 mm of wood at a time) a builder uses to reach his graduation/tap tone/basic ring mode X-mode tuning but it is possible to do those adjustments to a playable instrument. Graduating a fully set up, stringed and tuned instrument is a much more direct and hopefully more objective method than taking the top off doing a re graduation and testing the instrument a few days later. At least to me doing a conventional re graduation by taking the top off sounds as an essentially random process.

11 hours ago, David Beard said:

These things suggest that precise specific graduations of plates maybe much less useful than many modern makers presume and believe.

Yes I second that. I think the fact that there are a number of graduation maps floating around and the fact that a plain copy (for example using a numerical router) of a well known well sounding instrument doesn't necessarily produce an instrument even close to the sound of the original is the proof!
My own view is that the instrument works much like the strings. You don't buy strings that have painted markings on them showing how much the string should be stretched to be in tone ... it simply doesn't work. One has to tune the string acoustically to get it in tune. I also think that there is almost an infinitude of working graduations for a good instrument but the graduations aren't random. When you know the behavior of the plates of a violin you can deduce a number of faults by playing the instrument and by listening for known faults that you know how to fix by very slight re graduation of known areas known to influence the sound in a specific way.
 

11 hours ago, David Beard said:

As we all know, resonances can be tuned.  This tuning has two specific aspects, the frequency and the Q.  All such resonances will actually respond to a little range of frequencies.  The 'frequency' of the resonance will then be taken as the center of that range of response, or as the point of strongest response.  The Q then is a measure of the breadth of the resonance response.  The physics of resonances tells us that a low Q resonance will respond more weakly, buy to a broader range of frequencies.  A high Q resonance will respond more strongly, but only around a narrower range of frequencies around the central frequency of the resonance.

I think we have roughly the same opinion here too. Very sharp resonances with a high Q-value are not what you want. Every single small detail is a compromise. Some simple examples:

- Many violins have a tone that is slightly dry on the G and D strings. When you measure the spectrum to find the reason for the dryness you immediately see that the lowest notes of the instrument are essentially non existent. The "dryness" one hears is the set of harmonics of the tone being played with the base note inserted by the brain. The missing bass can easily be improved by making the channel between the neck block and the upper (neck) end of the bass bar slightly thinner. The effect is very strong and thinning too much creates a bovine kind of old German tone. Adjusting the channel at the other end of the bass bar can to some extent compensate for to heavy changes. Changes of 1/100 mm in thickness are easy to hear but you can't mechanically measure a change that small.

- A overly strong resonance may cause wolf notes. It is easy to add a wolf note on the A-string roughly at the tone B (european H) by thinning the area just below the neck block on the bottom plate. Getting a too loud B in this way can be compensated partly by thinning the corresponding bottom area. My view is that we are playing with relations here not absolute resonances. Tapping the bottom on a violin with the too strong B resonance shows that the center of the bottom has a tap tone (whatever it is worth) that is lower than the too thin neck area. My view is that the problem usually requires too much effort to fix without opening the instrument. The solution is to make the center part slightly thinner in relation to the edges.

12 hours ago, David Beard said:

A driven system where overall radiance and even response acrosas the musical range requires that most individual supporting oscilators veer toward lower Qs contradicts the notion that very precise tunings of resonances matters, except where directly part of the stringing system. 

I think you interpret the word "tuning" in a too narrow sense. To me the tuning of the plates is relative adjustments where I look for a specific timbre. An instrument that is properly built according to "good" rules of thumb will produce a strong enough sound when properly set up but the timbre may not be what you sought.

An example: I think many violins don't radiate high frequencies properly. The main high frequency  radiating areas are close to the f-holes. Measurements seem to indicated that the maximum mechanical vibration when playing on the G-string is found starting perhaps 20 mm up from the bass side f-hole and the area is some 500 mm long and20-30mm wide going NNW. To get a proper timbre on the G-string we want to connect this vibrating area to the f-hole's outer edge (outer edge because the upper part of the f-hole blocks energy partly from reaching the inner edge). Tuning in this case means to make sure there is a proper acoustical impedance match between the main vibrating area and the edge of the f-hole.  Adjusting/tuning means that I initially leave the edge thick to allow later adjustment. When I have adjusted the bass channel (see above) to give a proper darkness to the tone I adjust the maximum vibrating area to give balance between the different strings in this case between G and D strings. When the balance is OK I finally add high frequency timbre by properly thinning the edge to couple to the maximum vibrating area. Tuning in this case means I want the same tap tone in the maximum vibrating area and the f-hole edge. Adjusting the f-hole edge must be done very carefully because it is easy to over do it.

Thanks for good comments!

[edi malinaric]

26 minutes ago, Lars Silen said:

- snip -

Measurements seem to indicated that the maximum mechanical vibration when playing on the G-string is found starting perhaps 20 mm up from the bass side f-hole and the area is some 500 mm long and20-30mm wide going NNW.

- snip

Thanks for good comments!

Eeeek! -

"500mm long" - are we fine tuning a double bass?

If so - why? :-)

cheers edi

[sospiri]

On ‎3‎/‎9‎/‎2019 at 3:35 PM, violinsRus said:

not sure what you mean by 'bridge tuning', but the job of fitting a bridge involves removing wood from many critical places on the bridge blank, and most of that effort is to improve the sound the violin produces.  You can't just slap a bridge blank on a belt sander and expect it to have the same outcome as a job done with sharp tools, care and precision, and a wealth of experience.  I'm still just learning...

 I'm not sure about 'bridge tuning' either. Just like sound post tinkering and afterlength adjusting etc, it seems like a load of kidology that many believe and imagine they can perceive a "tonal  improvement"

Bridge fitting... different matter, I've studied the video and have the right tools 

 

[Lars Silen]

3 hours ago, edi malinaric said:

Eeeek! -

"500mm long" - are we fine tuning a double bass?

If so - why? :-)

cheers edi

You should remember that zero is nothing or altarnatively you build a bigger violin like a double bass.

Yes: There is one extra zero .

[edi malinaric]

2 hours ago, Lars Silen said:

You should remember that zero is nothing or altarnatively you build a bigger violin like a double bass.

Yes: There is one extra zero . 

Hi Lars - When I was 11 years old I scaled up the plans of a Me 109 from the centrefold of an aero-modelling magazine.

Even then I had my eye on the bigger picture and I drew it at twice the size. (Over the years I lost contact with my grandfather's drawing board but his Tee Square is still hanging in my drawing office. At the time it was longer than I was tall).

The build went off successfully but flight testing was a failure - it was tremendously tail heavy.

It was then that, all by myself, I discovered the square-cube!  (double the size and the weight increases by eight)

Yes - one must keep a keen eye out on the value of numbers.

cheers edi