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David Beard

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Posts posted by David Beard

  1. And here are the data for 49 del Gesús. Thicker, but the differences are smaller around the f-holes, especially the inner wings and sides.

    Thank you for posting maps from such large samplings, and with deviations showing!

    I don't suppose you could post maps of the rest of the top and back?

    Really great to see basic data presented cleanly and simply.

  2. One area of theory that seems to be getting less attention that it should is arching. The only treatment vaguely close (that I'm aware of) is the Woodhouse paper on confined modes of S-shaped steel, which does not appear to have much utility for violinmakers.

    I have looked a little at the "ring mode" as described by Evan Davis, just to get some idea where we are on the frequecy-curvature field, and it looks to me like arching would have significant influence on mode shapes (and thus radiativity) even up at the higher frequencies.

    The picture is complicated further by the nature of wood, where the properties can vary wildly depending on the angle of the grain to the surface. Some of that variation may contribute to good sound... or not... we don't really know. So advocates of plate bending, in an effort to maximize stiffness in all directions at all times, might not be aiming in the right direction... or might... we don't really know.

    There is plenty of concern about total arching, long and crossarch patterns, cycloids, and the like, but not much of the "how" and "why" of the arching from a fundamental physics/acoustics view.

    I'll put that on my "to do" list.

    I thank you for your exceptionally clear headed approach to applying science to the art of violin making.

    I would suggest that since resonances are readily measurable, they have filled the view screen and obscured other lines of observation for most scientifically inclined violin lovers.

    Certainly resonance plays a part. But the violin is largely a driven system. Resonances ARE the story for systems that passively respond to an unorganized input, but they are NOT the full story for driven systems, nor for systems that transform and radiate a highly organized input. Indeed, in some driven systems resonances are simply unwanted pests.

    I wish more of our scientifically talented people would turn down their attention to the blatantly observable topics of resonance and varnish just a bit and ask: WHAT ELSE MIGHT MATTER??

  3. Great thread!

    I had a long reply, but it looked way too tiresome and I deleted it in favor of a brief opinion statement:

    Plate tuning: nope*

    Chladni patterns: nope

    Micro-tuning: nope

    modal analysis: not yet**

    wood properties: some help

    ... At the moment, the "trial and error" theory still looks very efficient.

    ... I got the idea to ask this question after making my 25th violin and realized that I no longer use plate tuning à la Hutchinson. In fact, I wish I never heard of plate tuning.

    ... But IMHO I think many well-meaning, smart researchers have lost focus. Noon and Buen maintain that focus. ;) ...

    ... To me this is the single greatest contribution that Science has made to violin making is; that Science has, more than anybody else, eliminated the most 'smoking guns'.

    ... Surely we see this as a human endeavour, and do not seek an answer from Science. So why do we seek an answer on Making?

    ... I think that people like Noon and Buen to mention a few, are laying some important foundations, for someone later to come along, and build on. ...

    Science has given us a wealth of info, but few answers. Perhaps, as I think many have suggested, this is partly because violin making is at root a human art and not a science.

    trying to get modern science to make a better stradivari is like trying to get jackson pollack or salvador dali to help you paint a better mona lisa or last supper ...

    ... Trying to achieve the Strad or Guarneri sound through immersion in the spirit of their time is, I believe, filled with at least as many dead-ends as any other route (or more so). ...

    This I'm not convinced of. Dead-ends are part of any discovery method. In a sense, they don't really matter. What counts is that 'historic immersion' and 'hands on' yield a lot of good fruit.

    As a new maker, learning now, and building my first instruments now, I find writings from the 'immersion' crowd to be helpful beyond all other sources: Sacconi, Darnton, Hargrave, et al.

    The other source of supreme usefulness is direct reports and observations of the old instruments. In this, science plays a hand. The internet gives a wealth of access to sounds, pictures, words, and data. Science and computers enable our wonderful forum, and many of the tools that help us learn from the experience of others.

    Only as a distance third have scientific studies seemed helpful in themselves. Yet, some of them are very helpful indeed.

    Perhaps some of the weakness of scientific results is that science thrives on separating components of a problem to arrive at fundamental understanding, while the violin maker must be concerned with fitting the components together into an effective whole.

    Science can play a part, but making is not equal to physics + chemistry + engineering. It is also part history, culture, and art.

    For me, some of the most helpful scientific studies have placed information in a complex context. For example, some of the CT scan works present several coordinated maps giving thickness, density, and contour/elevation of the same instrument. To me, these are more helpful than any study that probes one of these separately. Similarly, there are some motion animations that show the coordination of movement through the whole instrument and the air motion for varied frequencies.

  4. To me, "response time" is still a term lacking an adequate and agreed-on definition. If it was about how quickly a string can go into a stable vibration regimen, it would leave out the "crunches and consonants" which can add so much to an instrument, and to a player's performance.

    Yes! It doesn't seem like a simple single quantity.

    Here are some impressions from my own playing and preferences:

    It seems that in instruments with a more satisfying tonal range, there are multiple components to the sound and different kinds of voices available from the instrument, with some components responding faster than others. My sense is that in better instruments the sibilants/stridents and other brighter components respond the fastest, and that there is a basic 'clean' voice that responds quickly. But under that there is both a blowy/airy voice and a gutsy/deep voice available - which are both slower to invoke. With pressure or closer to the bridge there are additional bitier and driven sounds possible, with response times somewhere in the middle.

    It seems as if the differences in response times are helpful, aiding in control and selection of voice as desired.

    Perhaps others can give more specific description of the mechanisms behind these effects? I'd love to get quantitative about these observations, but for me they are just impressions at this point.

    Beyond response times for different components of the sound and different voices, there is a separate set of response effects around the change of pitch/finger/string within one tonal voice. A desirable example of this is the special kind of crisp almost 'popping' transition from pitch to pitch that is available on some violins. You can sometimes hear the same effect with other kinds of instruments, clarinets for example. This effect seems to require both a lingering and persistence of the old pitch, combined with a suddenness and full blown cutting in of the new pitch.

    It does seem like it would be helpful to separate and distinguish different aspects of 'response time'.

  5. Rub your finger on the top of the bridge and notice which direction makes all the noise.

    I just tried this on a viola. Certainly most of the sound comes with rubbing along the arc of the bridge. But there is also a higher almost hissing sound when rubbing in the strings direction. Both seem significant.

  6. That's a great modern take on 'pink'. Very interesting.

    I've heard a very antiquated use of 'pink' as more of a process of whiting out a color. Similarly, 'lake' later was sometimes used to name a type of red, but originally was more about a particular coloring making process.

    In this archaic sense, you might have 'pinks' based on other colors then red or purple.

    I couldn't find much of any reference to this usage on the web. Except for some mentions of 'pink' to refer to a yellow lake of buckthorn. 'English Pink'

  7. "In 1982, Nagyvary pioneered the use of cutting edge microanalysis, the EDX spectroscopy, to show that the wood of a Guarneri cello was treated with wood ash."

    From http://www.nagyvaryviolins.com/about.html

    "To soak or not to soak?"

    "We first applied this method in 1980 to wood chips from a cello by Andrea Guarneri (Joseph's grandfather) and found that Si, K and Cl were the dominant elements, among several minor components. This composition could be compatible with a past history of soaking the original wood in a suspension of wood ash in water. "

    From http://www.rsc.org/education/EiC/issues/2005July/violins.asp

    Nagyvary seems to begin from the observation that Cremona violins and woodworking in general are less worm prone then works from other areas of Italy.

    I wonder if any of our Italian based members have noted this same thing? Certainly a quick search of the word 'worm' on Cozio.com does not seem to confirm Nagyvary at all.

  8. I've learned a lot from your varnish articles, and I look forward to reading your future studies on violins.

    However, I do want to point out a possible flaw in looking for 'uniqueness of sound' from an listener's viewpoint.

    In a sense, one could say that there are several audiences that value and praise the top instruments, but listener's aren't really one of them. The people who covet and treasure these objects are Players/Performers, Collectors, Buyers/Sellers, and Makers/Restorers. Collectors covet art (including great violins} for who knows why, but it won't show up in a listening test. Makers/Restorers earn a living emulating and repairing the old violins, and sing their praises. Players/Performers who have to make a living in front of audiences feel more empowered, expressive, communicative, and heard playing these instruments. But that doesn't necessarily mean the audience directly understands or hears what makes such a great difference to the performer.

    Ultimately, only the buyers and sellers actually set the values. They for the most part enjoy an excellent investment, or satisfying possession.

    The idea that these instruments are objectively better for a listener, may indeed be total myth. But it also in no way touches why these instruments are treasured.

  9. I certainly don't have any real objection to power tools. I just think working without them can be a thought provoking experiment.

    Here's an example of how avoiding the band saw might lead to real tonal differences: hand sawing is harder to do >> splitting stock saves labor >> split stock results in rejecting wood with bad splitting characteristics and automatically gives some grain orientation >> outcome is a selection and use of wood that might have different tonal qualities.

    As a side point, I tend to think that if we all demanded split stock instead of sawn wood, our suppliers would need to adjust and high quality stock without run out might be more available and at better prices.

  10. I hear you.

    Still, that thought doesn't negate studying how the early violin makers did what they did, or figuring out exactly what they did, in order to learn how they got their results.

    In any art form (IMO) there comes a time when the learning must turn into doing, and in the doing, I too believe that perhaps the main thrust of our efforts today should be in creating something new today that functions well today, rather than strictly and only producing exact copies of the makers of the past even when the direct evidence shows that we may not really be getting their exact results. (Whatever, since this is difficult to determine with any accuracy)

    Luckily, there are no "violin police" (except those self-appointed ones that we occasionally run into) and we can and will do exactly as we choose in this regard -

    Myself?

    I prefer to listen to the great makers of today first, and study the great makers of the past after that, as a sport of pass-time effort. After all, the great makers of today are still with us, and many of them are here posting today or tomorrow. And many of them have already been there and done that - irrespective of exactly what "that" might be, including making a lifetime study of the "old masters".

    In most cases, I don't have to figure out what they do, because they are willing to say outright what they do. In fact, many times I find them trying to pound into our collective brains, exactly what they have found that works for them, even when and if it goes against many of the dogmatic and persistent beliefs that theorists and armchair luthiers might have, in regard to exactly what Strad (and the rest of the good old boys) did.

    Yes. I certainly respect that there is a discovery and learning value in copying master works. Indeed, that has been a device in art education for centuries.

    What still puzzles me is that while we don't laugh at a maker who chases tenths of a millimeter or replicates stains and wear in making copy, we do seem to laugh at someone who sets aside power tools and modern conveniences. To me that seems an equally valid device for chasing after the old masters.

    Perhaps there is more to be gained by trying to copy their methods, materials, and traditions?

  11. Just wondering if part of the secret of the old masters might have been aiming to make good violins, rather than copies of good violins. Just possibly it might be easier to make a good violin if you aren't also trying to achieve a separate goal of faithfully copying a model?

    I doubt the old masters ever hesitated in choosing between emulating the exact measurement or appearance of a model, versus doing what seems best for the piece of wood and instrument in hand?

    It seems like the old masters worked squarely within an established tradition, but at the same time they weren't very consistent. It doesn't seem like they would have made very good copyists?

  12. -- actonern, Here is a revised drawing:

    post-30802-0-35254900-1318296419_thumb.jpg

    -- kubasa, Thanks for the link. Mr. Hargrave's writings are always very very helpful!!

    -- violins88, used old copies of Visio and Photoshop. Not the best, just what I have on hand.

    -- Mr. Carlson,

    Seems I was stressing over what appears to be a non-essential relationship. More, I had expected the form line to match the inside purf line, and that was just wrong. Thank you for giving more details and helping me shake off some false assumptions.

    The outline was constructed from a planned design, not actually a copy of any one instrument. At this stage, everything is still exploration for me. In this case, I etched the design on to the back wood first and will experiment with building upward from there. I want to build the form now, so I needed to chase down these last questions. As you suggest, once the form and sides are built, I may need to reconcile the outline of the back. I hope this need doesn't arise, but I've left some margin on the roughed out back just in case. I expect the top will require some reconciling between the design plan and the actual rib line.

    Thanks,

    David

  13. Hi David,

    There is no fixed amount of overhang as there is no fixed amount of edge outside the purfling but .......

    Sacconi suggested that when tracing the outline of an instrument it is useful to use the outermost line of the purfling as it is often more reliable than the worn edges of an old instrument. In your diagram you can see that the inside of the rib and the outside of the purfling are in close alignment. On other instruments, with different proportions of overhang and border width, it would be necessary to make a correction to get closer to the true line of the form after completion of the initial tracing.

    Bruce

    Hi Bruce,

    I'm not sure I fully understand? Would these corrections mostly be toward a narrower overhang?

    David

  14. Do you mind if I ask why you're asking?

    Hi ctviolin:

    I've set the outline and purfling for a violin, and already started carving the back.

    Now I want to make an inside mold for the sides, but I'm unsure how to proceed. I’d assumed that my mold line would follow my purf line. But now I’m unsure. The resuling overhangs seem like they might be a bit excessive?

    When I look at various tables of measurements, and even measurements on some posters and in articles, it seems like a fairly normal relationship would be:

    'inset of purfling' = 'overhang' + 'rib thickness'

    So that is what I showed in the picture.

    Somehow however, the picture seems more like the extreme of acceptable overhangs, rather then a 'normal' overhang.

    Obviously, many instruments old and new have less overhang, and often uneven overhang.

    So I'd love to get a better sense of the range of acceptable and ideal overhangs. I was also assuming that the relationship between the purf line and the rib line would be important, but maybe I'm wrong. Maybe their relationship can vary a lot without any great significance?

    I'm hoping for help understanding these points.

    David

  15. I have a clear looking piece of rock, given to me by an employee who was aware of my fascination with optics, which turns text upside down.

    He also bought me a book on thin optical films. These can be things which produce interesting color effects, like the colors produced by a thin oil film on water.

    I don't know of any "artist treatise" books which go into these things very much. If you rely totally on artist painter crap, you'll be missing a whole lot. Yes, I'm kind of trying to say that artist airheads don't always furnish information which is as valuable as that produced by serious researchers.

    jezzupe, this wasn't directed at you. I just used your post as a jumping off point.

    post-30802-0-81974700-1317421794_thumb.jpg

    I love this photo from wikipedia.

    Apparently the glass is neither red nor blue, but it has lots of small particulate dispersed through it. Longer wavelength red light preferentially passes through the particles, giving the red pass through light. Shorter wavelength blue light preferentially scatters, giving the overall blue cast -- same dynamics as sky and sunset.

  16. To make matters more confusing, there is sometimes a difference in the aims and terminology for modern paints versus older techniques. Since much of our work centers on the methods used in Italy between 1550 to 1750, the old concepts and terms are going to keep intruding, Perhaps we should adopt some of those old meanings as more or less standard in luthiery?

    When we mix and cook our own preparations, or grind pigment by hand, we are bucking the trends since 1800. I think the older language and sense of things will be more friendly toward our efforts.

    Some examples of new versus old: premixed product v. home recipe; one unified coating v. layered structure; color choice v. pigment choice; milled pigment tube color v. hand ground pigment; mostly oil body with minimal particle nature v. mostly particle nature with only a temper of binder; synthetic pigment v. natural pigment.

    Pantone color charts and numeric color spaces and pigments with a flat narrow and well defined color tone are all modern aims and methods. Hand and eye mixture of basic natural pigments with natural variation and breadth of color is the old concept.

    The modern ways sell virtues of ‘permanence’, ‘ease’, ‘uniformity’, ‘predictability’, but mostly these products and marketing approaches emerged from a combination of invention and the forces of commercialization and mass production. These product values aren’t automatically superior for the purpose of violin making.

    In addition to good references like Ralph Mayer’s that sort of straddle old and new ways, I suggest we also look to historic texts like Cennini and Theophilus. These are both widely available in translations and offer a window on ways that are close to our craft’s history.

    I believe we should leave some of the broader terms to modern scientific definitions. We should no more redefine ‘transparent’, ‘opaque’, ‘saturation’, and ‘hue’ then we should attempt to redefine ‘acid’ or ‘salt’.

    Other useful terms are peculiar to the art and tradition of mixing and using pigments and binders, but most of these have historical meaning we might as well honor: ‘mass tone’, ‘ground’, ‘glaze’, ‘paint’, ‘pink’, ‘lake’, ‘tincture’

    A few terms are caught in a tug of war. ‘Varnish’ now seems to mean almost any outer coating that isn’t ‘paint’, but earlier usage seems to be more limited to simply clear cooked combinations of oil and resin.

    Sorry for the rant. Obviously this stuff is mostly just my opinion.

  17. I don't think your definition matches that used in painting, where mass tone is the color of a pigment when it's applied thick, and undertone is the color of the pigment laid thin. Most painters' pigments have identical mass and undertone, in which special case your definition would work, but there are many which are different thin or thick, in which case the mass tone is ONLY the thick tone.

    We aren't the first or the only community to tromp through these issues.

    While modern pigments and paint vendors often strive to make the mass tone and undertone equal, part of the appeal and special character of actual natural ground historical pigments is how mass and undertone DON'T neccesarily match. We do ourselves a disservice to confuse issues of transparency versus opacity with issues of change in the apparent color tone between thick and thin applications. Similarly, we probably shouldn't reinvent vocubabularies of hue or transparency, as both are highly develop in other fields --both arts and science.

    transparency and pigments

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