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. Hi Anders, I recall reading an interview with the violin maker Peter Greiner where he mentions his close collaboration with the physicist Heinrich Duunwald. Greiner was asked what his secret of violin success was and his answer was something like "Why should I describe what I'm doing--anybody could then make a great violin"
  2. The M2 and M5 (and a bunch of others) and the assembled modes are indeed related as shown by Colin Gough's finite element analysis (attached) where he starts with the free plate mode frequencies and then gradually adds the stiffening of the ribs. It is very easy to make a plate of uniform thickness with the aid of simple calipers. But the plates of famous old Italian instruments show quite a bit of thickness non uniformity. It is not know if this variation is due to indifferent workmanship or whether it was intentional. Nevertheless it does affect the various plate and assembled mode frequencies and therefore the resultant sound. Gough.pdf
  3. There seems to be three big variables regarding arching: The height of the arching, the longitudinal arch shape, and the transverse arch shapes along the length. Is there some modern or historic commonality that works best? My guess is that there will be favorites all over the place.
  4. I think the vertical G string forces going into the bass bridge foot are the same as the vertical E string forces going into the treble foot. So reversing the strings wouldn't change these forces.
  5. You were still bowing with your right hand or did you switch that too?
  6. If Dennis's arch templets look nice why wouldn't the plate arches also look nice?
  7. I've monitored the M5/M2 ratio while thinning the tops. Attached is a graph of how that ratio changed as I removed wood in various places. The "Sacconi Plateau" area is very sensitive. Removing wood there lowers M2 while raising M5 thus raising the ratio. Also attached is a photo of the Titian Strad top plate which shows Stradivari didn't use a "Sacconi Plateau" like Curtin has shown for his plates.
  8. Joseph Curtin reported some top plate mode 5 and mode 2 frequencies of nine old Italian violins in his 2006 Strad article "Tap Routine" which is attached. Please notice that he also lists the weights of these plates one of which is the 1716 Booth Strad that Don just mentioned. Is there any more similar data on other good violins' plates published? Curtin's article mentioned that Carleen Hutchins suggested he should watch his plate weights back in 1986. He wrote his article 30 years later and now after another 14 years this simple idea still doesn't seem to be catching on as important. Tap_Routine_-_J_Curtins_Strad_article_06.pdf
  9. This kind of experiment was recently done in the Bilbao Project at the BELE Basque Violin Making School in Spain. Violins were made with the Strad Huberman design using various combination of top and back plates having pliant(floppy), medium, and resistant stiffnesses. The plates and assembled violins were throughly tested and blind listening tests were done to determine preferences but the data and results have not yet been published. See the following: I expect to see a lot of scatter in the listening tests because people have different tastes. Of more importance to me is the player's opinions.
  10. Your graph is a perfect example why "plate tuning" is insufficient. If you thin your top plate to have a mode 5 frequency of 357Hz you hit that at two different weights: about 112g and then again at 101g. I don't believe that violins assembled with plates having these different weights would sound or play the same. Weight should be controlled too.
  11. My main point is that if you duplicate the stiffness, mass and damping of every violin part you have a good likelihood of duplicating the sound too. Just duplicating a few parts won't give you consistent results. Matching plate mode frequencies isn't a worthless thing to do, its just not sufficient.
  12. I suggest you give your violin's bridge a fingernail tap and do an Audacity analysis of the recorded sound. Then play glissandos on the E and G strings up to high positions and do an Audacity analysis of those sounds too. The frequency response curves will look very similar--all the resonance peaks will be at the same frequencies for both tests. You can believe what I say or believe your own eyes.
  13. A violin is indeed like a steel drum--if you hit it, it makes a sound. The frequency response curve of the sound coming from a hammer impact to the bridge is the same as when the strings are bowed in a glissando. Both methods excite the various body resonances the same way. The attached paper describes this more thoroughly. AilinZhang_JimWoodhouse_JASAJournal.pdf