David Beard

Once again you show your stripes. You find the data inconvenient for your theories, so you find a part that seems inconsistent to you and try and claim all the data is then to be disguarded. The data shows that all parts of the plates, and the blocks also show movement at various frequencies. Instead discrediting yourself by cherry picking what you want and working to dismiss the inconvenient, just go with it. The data shows movement you didn't expect. Deal with it. Embrace the truth instead of insisting existence needs your permission or understanding. Possible explanations for the apparently changing block height: -- possible scale discrepancy in presentation or data collection in that area of that animation -- rotation of block out of plane. If 'out of plane' motion data only was collected, then any rotation of the blocks out of plane will likely cause apparent height changes.

Hi Marty, Very much like the post. As you say, 'out of plane' plate motion is only one aspect of violin dynamics. Additional vibration dynamics for study do/might include: * 'in plane' plate motions * vibration modes of the enclosed air mass * air velocities at the soundholes * motions of the corner blocks, end blocks and post * motions of the sides and edges * motions of the string system including strings, tail piece, bridge, nut, and saddle * neck and fingerboard and whole body twists and bends * possible high frequency transmitive behaviors around the instrument * cut off behaviors * retentions, dampenings, and radiant behaviors ******** I see your case for progressing to a flat plate. It seems a fair direction for an innovative maker to develop. One caveat, the main arching in a traditional violin doesn't go directly to the edge, goes to a concave channel that cantilevers from thw edge. Further, the force vector at this juncture will combine an IP and OP component, so partly we might expect it to twist the channel instead of entirely push out on the sides, though that should happen also. Anyway, less direct than your illustration. The main thing though is many folk will see a flat plate as different enough to a new animal instead a kind of classical violin. That's an issue that won't matter to some people, and probably with each generation it will matter less to more and more people. Certainly noone cares about shape with electeic violins. But at the same time, this is an issue that will probably always matter to most classical players. I know it matters to me. I don't play for pay these days, but I'm not such a bad classical player. I keep my hand in playing by concertmastering Santa Barbara's monthly sight reading orchestra (Tchaikovsky's Little Russian last Sunday), principal in weekly quartet readings from Haydn to Ravel, and a few hours each week still teaching. It would be completely beyond me to use such a non-traditional instrument for playing the music I love. Not saying this is good or bad of me, just that is an inner truth for me. And I suspect that players in the future that fall in love with traditional classical literature will still greatly prefer the traditional instrument. For example, some of my friends play both cello and gamba. And they don't like playing gamba music on cello or cello music on gamba, though continuo with either is usually ok by them. Etc. There is strong aspect of some musics that is powerfully about characterist identity. One the other hand, if I were playing an all night contradance gig, I would be happy trying a flat top. In that space I personnally would feel less particular. I do believe that market for alternate instruments like yours will continue to expand. I imagine the percentage of non-classical violin playing going on in the world is probably increasing each year. So while I don't believe you have any prospect of winning people like me over, not now or in the future, I also don't think you need to worry aboit it.

That's your problem. The evidence shows all parts move in various ways at various frequencies. Deal with it. It doesn't need your permission or understanding to move. It does move. That you don't understand how indicates a failure in your thoughts. If you were brave, you would face the data and learn from it. This is the biggest reason I haven't treated you kindly.

Johannsson provides some good motion studies: Here is a Strad driven at 542hz. This shows the typical motion pattern for notes down to g string. Notice: ** The back moves more or less in and out as a whole. ** The post area of the top, and the post side extending deep into the lower bout and somewhat into the upper bout is moving in phase with the back ** The bass bar side, extending far into the lower and upper bouts is moving in opposite phase. ** As a result, the bridge table is rocking back and forth. For high enough frequencies, the plates behave quite differently. The plates end up behaving like soundboards or diaphragms, showing small patches of alternate phase. Here is a phase map of a top plate in a violin driven at 2680hz: Borman's site offers several different kinds of motion study animations: He gives a series of animations of Del Gesu's 1741 Vieuxtemp driven at a good number of different frequencies. The colors on these animations show wood thickness, so it's harder to see the pattern of phase areas. However, you can easily see the bass bar motion. Note: ** At lower frequencies the bass bar flexes in the middle in one comparatively simple motion. ** With higher frequencies, the bar has to move in more complex patterns. 281hz 1102hz He also provides a smaller series for a 1714 Strad. In this series, the colors represent the phase patterns: 392hz 1000hz Others have also provided various motion studies. Hopefully more such studies will keep coming.

The motion videos are observational and good enough to show us the many different modes of vibration in real violins. Ignoring experimental evidence is the difference between theory and fantasy. The most excellent predictive model that you or anyone can create is worthless compared to a little dose of concrete observation. For a theorist, ignoring any real observations is cowardly and destructive to any good work. As far as I can tell, the only real observation behind your work is the observation that violin archings often exhibit some straight line or near straight lines at some places along the surface. OK. That's a little something. Maybe a bit interesting? Maybe not so much? But it is something. But then you've created all these extended fantasies around that morsel. And these fantasy really don't neccesarily follow.

Different behaviors at different frequency. I still recommend viewing some of the actual motion studies available. These are not limited finite element simulation but visual studies of the actual motion of real violin plates of important violins being played at different frequencies. Stop guessing what the motions 'should be accoeding to theory". Go see what real motions actually are. Borman's site gives a good collection of motion videos. There others out there also. Google and go see for yourself.

Probably my imagination, but I always think he looks sad or uncomfortable in pictures with that fiddle.

-- reguz At least you finally showed us your STL idea that you wanted to talk about. The meaningless and often plain wrong noise before wasn't helpful. But telling what's actually on your mind is a good step. But it doesn't mean anyone will agree, or see what you're getting at, or believe it has any value. Most ideas are just fantasy. Very likely, most of us will conclude your idea is either irrelevant to good making, or just complete nonsense. I expect it's just nonsense. But I can tell you believe there's something important about it. When we theorize, as you have, it's very easy to mess up. There are so many ways to go wrong. We can see things that aren't actually there, like seeing animals in the shapes of clouds, or in patterns of stars. We can be wrong about cause and effect. We can wrongly fixate on a side effect and miss the central issue. We can make false chains of logic. Etc. And even when we get our hands on some idea that is actually true, we are very likely going to say it wrong, or try to develop the idea from the wrong starting point. One great danger for any theorist is to falsely extent from something true to include something false. So for a simplistic example: "I can see clouds are white, therefore they're made of cotton." A theorist absolutly needs skeptism. Sure, it takes enthusiasm and creativity to try and develop an idea. But then you need to attack your own ideas. If you accept any little bit of falseness, then all that follows after will be non-sense. When you think you have a good idea, you need to try and rip it apart as if your life depended on it. Don't try to prove your idea, try to disprove it. Then when you think your idea survived, devise experiments and tests. Again, don't aim to prove. Aim to discover the errors, to remove the over statements. If your idea still seems to be standing, then ruethelessly attack the scope. Try to discover the limits of where and how the idea really applies. Theorizing is a bit like cliff climbing, the further you climb the greater the danger of falling. Grounding the steps of your in observational/experimental challenge is like clamping im your rope for safety. Try to proceed in the smallest and most confirmed steps conceivable. With physical vibrational systems, it's good to remember that most behaviors are limited to only some frequency ranges, and that the thing you found is only going to be one mode of behavior among many. It's never going to be the one and only thing that's important. Lastly, when presenting an idea, don't try to discredit true things that seem to compete with your idea. Don't try to prove A not B when the truth is A and B. Silly example: if you're making the case that the gravity of the Sun pulls on Earth and everyone on it, don't try to say the gravity of the Earth doesn't also pull on people. My favorite example of misguided theorizing comes from 1910 when Whitehead and Russell tried to prove the apparently obvious proposition that 1+1 = 2. The wanted to accomplish this by developing theoretically from the simplest possible assumptions of mathematical logic. But this didn't end up being simple. It took them several hundred pages of dense symbolic logic to get there, but they arrived where they had tried to go: 1+1=2 QED. So why so difficult to prove such a simple absolute truth? Well, a few years later the proposition was very simply refuted by counterexample. It turns out not to be an absolute truth! If you simply define 1+1=0 and 1*1=1, you get a completely consistent mathematical system with only the numbers 1 and 0. It turns out that 1 + 1= 2 only by definition, it isn't an absolute truth. Their hundreds of pages of proof were only off-track fantasy.

Reguz, you repeated wrote that the lack of measurable weight change somehow demonstrated your point. Are you now denying you said those things? Are you now acknowledging that neither weight change nor the lack of weight change are relevant?

You are very confused to believe the weight and any motion are related. They are not.

Still, the lower bout width is very narrow.

Is this a small size violin reworked to a longer length? The proportions are in many ways unusual. How long is the body? How long is the body stop?

like!

Reguz-- Modes. A structure will tend to move in ALL the available ways possible, the balance favoring path of least risist. You have analyzed ONE of a number of perspectives. The one you take begins from seeing the post as immobile. There is nothing wrong with looking from that view, but it DOES NOT have any special priority above looking at any other point as an immobile reference. There are many modes of flex or vibration in a violin. And they pretty much all play roles. ****** One can only go so far considering real systems only theoretically. We can easily get lost or disoriented in theoretic thought. The farther we try to go without grounding back in real observation the more likely to get turned around and off track. We're lucky to live in a time when real motion studies of violin plate motions are readily available to us. (google Borman i.e.) You should spend some good time watching these. You will find that the activation of various modes of motion in real plate observations is frequency dependent. A further thing to consider is that while it is theoretically valid to take any point you choose in a system as an immomible reference, there is nevertheless considerable virtue in prefering a reference that yields a comparatively simpler or more elegant perspective. Thus there is nothing wrong with choosing the Moon as reference for the motions of our solar system, or the Earth, but a simpler understanding emerges if we choose the Sun. In a similar way, if you watch plate motion studies from many frequencies, you will find that in some modes of motion the soundpost is easily viewed as immobile, but in many other modes not so. Similar with the corners. There basically are no parts that aren't mobile in some of the modes.

Highly recommend this book: https://www.amazon.com/Why-Buildings-Fall-Down-Structures/dp/B00A2MN60W