Marty Kasprzyk

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About Marty Kasprzyk

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    Enthusiast
  • Birthday 06/02/1945

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    Male
  • Location
    Olcott, NY, USA
  • Interests
    Wine making, gardening, dog training,

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  1. It's sad that the more you interact with them the faster they die.
  2. How are How are you making the top plate removable? Some people have suggested using Kraft paper in the glue joint.
  3. After making a few more instruments I forget what the earlier ones were doing. Those pretty graphs and numbers make pretty good records. Some runners run races just for the fun of it. Others record their times to see if they are improving.
  4. Colin Gough has shown with a finite element analysis that free plate modes 1, 2 & 5 morph into low frequency "signature modes" when the plates are attached to then ribs. And George Bissinger has shown that there is little correlation between the frequency of signature modes and violin quality anyway. And you have often mentioned that the high frequency range is more important than the low frequency range and that the idea of plate tuning (M1, 2, 5) is of little merit. Others have also abandoned the idea of plate tuning to frequency targets. But does this suggest that "plate tuning" should be done for much higher frequency plate modes: M10, 15... whatever instead of the lower ones? I'm wondering if "plate tuning" is not worthwhile or whether enough mode targets have been used in the past. I'm guessing that if you were trying to duplicate plates then many mode frequencies have to be matched not just modes 1, 2 and most often just mode 5.
  5. Strad's use of internal molds and patterns was a modern standardization move away from the older methods. Maybe Strad had shelves stacked with shaped top and back plates, rib assemblies, necks etc. and they just grabbed interchangeable parts and assembled them.
  6. What does a clean tap tone look like if you do a frequency analysis? What's a dirty one look like?
  7. The M5/M2=2, octave goal came from the Strad top plate Hutchens had a chance to study. She warned people about the risk of using just one data point to make a conclusion. Two notes exactly an octave apart sounds very pleasant and clear and it seems reasonable to jump to a conclusion that the old makers might have wanted to achieve this with their plate tap tones. Recently however it has been found that other Strad violin plates had M5/M2 ratios around 2.3 or expressed as a fraction of about 9/7 . Two simultaneous notes having this this ratio would be dissonant, rough or harsh. So I think the goal of achieving a clear ringing tone when held at the M5 and M2 node cross lines is questionable.
  8. It might have far less ring because Its vibration energy is being quickly transferred to the surrounding air (radiation damping from heating the air or producing sound). Joseph Curtin mentioned that a Strad top plate he tested had a dull thud when tapped. Maybe the often stated goal of having a long ring is incorrect.
  9. One consequence of low arches is that the bridge has to be correspondingly higher to maintain bowing clearances. Increasing the bridge height H while maintaining standard foot width W increases the bridge H/W ratio (like cello bridges have). This increased lever-arm in turn increases the bridge's vibration forces on the top plate during bowing which simultaneously increases both loudness and worsens any wolf notes. If you want to try lower arch heights I suggest either decreasing the C bout width to achieve good bow clearance and/or using wider bridge feet. If you plotted top plate arch heights vs. construction year for Amati, Stainer, Strad, DG violins you might conclude that the plates should be pretty flat by now. But fossils show evolution stopped about 200 years ago.
  10. If you don't thin the areas left and right of the end blocks and have a straight line of thickness of a "Sacconi's platform", like modern violins often have, the mode 2 frequency is relatively high and the mode 5 is a little low compared to old Italian violins. Their M5/M2 ratio is around 2.0. Carleen Hutchins championed this double octave scheme which has often been discredited now that more studies have recently been done on old Italian violins. If you thin the plate areas left and right of the end blocks like shown in Don's Strad example the consequence is that the mode 2 frequency goes down while the mode 5 frequency goes up a little and their ratio of frequencies is around 2.3 for Strad and other similar old Italian top top plates. The various mode frequencies (M1, M2, M5) are affected by the graduation and arching schemes and the wood properties. I you would like to duplicate the sound character of a particular instrument I suggest you try to duplicate everything as closely as possible. Or you can forget all this stuff and just make violins. "Don't worry, be happy."
  11. Does the change ln the bow hair with humidity also change how nice the violins sound? My ex-wife had a lot of bad hair days.
  12. If you mess around enough with the tailpiece stuff you mentioned we might be able get it to have a resonance mode at the same frequency as a wolf note thereby taming it. However if you have more than one wolf note it might be very difficult to get the tailpiece to have other resonance frequencies that also match those other wolf notes too. So it seems reasonable to pick the worst wolf note to tame and let the others go. This could suggest that maybe we should have a separate tailpiece for each string so we could tame up to four wolfnotes instead of just one.
  13. Attached is a reference where the top plate is deliberately split lengthwise to make its vibration mode shapes nonsymmetrical. We always take great care to have a good glued center joint. Maybe it would be be better not to glue them together. split plate, ISMA2010_Besnainou.pdf
  14. An experiment was done at the Oberlin Acoustics Workshop about eight years ago where north and south narrow cuts were made from the f hole upper and lower eyes in 1 cm increments. This was done on an inexpensive factory violin and it was discovered that the sound quality actually improved up until the cuts were quite long. Later at home I repeated a similar experiment on one of my own violas and found the same thing. When the cuts were made too long the slots were filled with glue to shorten them to the optimum length. Subsequent experiments on enlarging the f hole areas showed that surprisingly large area increases were needed to give noticeable changes (mostly A0 frequency increases). This led me to believe that it was the length of the f holes rather than their areas that was the important f hole variable. Apparently the amount of movement of the plate island between the f holes has a large influence on the sound character. It wouldn't surprise me if some cracks were actually beneficial as long as they are wide enough not to buzz.
  15. Have you tried Dominant light (weich) tension strings?