Marty Kasprzyk

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About Marty Kasprzyk

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  • Birthday 06/02/1945

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    Olcott, NY, USA
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    Wine making, gardening, dog training,

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  1. Some people will like it while others won't. The various signature mode frequencies are dependent upon arch height and plate thickness. If you are trying to keep the same frequencies you might want to make your low arched top a little thicker. On the other hand there isn't much of a correlation between preferences and mode frequencies anyways. But as Don mentioned the amplitudes of these are more important. Too thin will sound tubby probably with some wolf notes and too thick will sound shrill or harsh. "Don't worry, be happy"
  2. Bran made some good points about points. Anechoic foam materials are shaped with points to trap sound waves and prevent their reflections that would cause resonances.
  3. Other than for bashing the right hand thumb and the bow what is the purpose of your long corner points?
  4. That's what I think too. Thin sounds good but is weak. There is a limit of how thin you can go in the quest for better performance. I remember a USA sailboat doing really well in a 12 meter American Cup race until it broke in half.
  5. I agree but when you have big humidity increases the wood expands while the steel strings don't stretch much and the result puts a lot more tension on the instrument which can be harmful. Either carefully control the humidity or retune your instrument often if you are using steel core strings.
  6. It might help to add some sort of f holes or C holes, with their eyes at the cardiod's focal points.
  7. The Woodhouse paper you cited has a reference which I think shows some interesting violin experiments rather than mathematical predictions. [6] E. V. Jansson, B. K. Niewczyk: On the acoustics of the vi- olin: bridge or body hill. J. Catgut Acoust. Soc. Series 2 3 (1999) 23–27. One of Jansson's experiments shows the effect of adding stiffening strips across the f hole island. The bridge hill frequency changes dramatically.
  8. What were the failings of the old technology 3d router duplicators?
  9. Beautifully perfect. Can you introduce some random errors in the cnc so it looks like it was carved by a human being? "The secret of success is sincerity. Once you can fake that you've got it made."
  10. Great photo! thanks It shows the level bridge and level end of the fingerboard much better than my photo. I wonder what's the best amount of twist.
  11. I've got about 20 of my violas. I save the pegs and strings.
  12. I think it is a mistake to ignore the cross grain elastic elastic modulus or its cross grain speed of sound because it does have a large effect. Cremer's (1) equation 11.24 seen below used a simple flat rectangular plate to model the mode frequencies of a violin top. If the width Lx of the plate for example is one half the length Ly then, because they are squared, the width direction contribution is four times greater than the long direction. But the wood's cross grain speed of sound Cx is typically only one fourth of the longitudinal speed of sound Cy so both directions contribute the
  13. Matthews and Kohut (1) electronically modified the sound frequency response curve of a Stradivari violin that had 17 prominent peaks and they increased the number of peaks to 20, 24, and 37 which is similar to increasing the modal density n. They concluded that 20 to 30 peaks that were not uniformly spaced but were either randomly or exponentially spaced gave increased brilliance, better note uniformity and vibrato response. I haven’t seen any later studies which contradict Matthews’ results. They also investigated the influences of different damping. Jim Woodhouse has written man