Jump to content
Maestronet Forums

Marty Kasprzyk

  • Posts

  • Joined

  • Last visited

Everything posted by Marty Kasprzyk

  1. Thanks for the kind offer but I have a CD copy here somewhere. Initially I thought the experiment was flawed because of the bridge problem you mentioned and because Rene should have adjusted the sound post first rather than afterward. But I took it apart later and installed a normal bass bar and bridge and my violin was still not so great so the non rocking bridge wasn't the entire problem. A much better experiment would have been to start with a good quality violin. If I ever make one I might try doing the experiment again.
  2. Well, it was inspired by a road kill squirrel. Maybe squished toads or possums etc. could look better for some people but you can't please everybody.
  3. The corpus receives most of the string vibrations from the two bridge feet and a small but significant amount from the neck attachment joint to the corpus. When you play it without the bridge its loudness is greatly reduced. The bridge is therefore quite helpful after all. The playing length of the string is increased when the bridge is removed so the string frequencies are lowered. This makes good intonation difficult at first. It is also difficult to play the C string because its bowing point is lowered. The bow hair hits the lower bout's bass side corner. The viola uses a sound post in the normal position. The flat top and nearly flat back at that point enable easy changes in the sound post position to be made because the post's length and fitting don't have to be changed. The bottom side of the spruce top has a Kraft paper disk glued on in the sound post region so that the post can be moved around without damaging the wood.
  4. Sorry for my delay in responding. A few good players have tried it and it was surprising and disappointing that they didn't even notice that the fingerboard was twisted and I had to point it out to them afterward. Maybe they were distracted by other things. One very good player thought it would also be nice to make the fingerboard's tilt angle adjustable which I will do soon. This will enable the player to use a higher or lower bow arm to their liking. The viola's lower bout is wider than normal (12 3/4in., 325mm) so I had to make my own shoulder rest and photos are attached. It has two 3mm graphite fiber tubes along which two balsa wood pads can slide to different positions. Some players liked the fit and light weight (60g) but others didn't seem to notice it. Apparently they were still distracted by other things.
  5. The fingerboard and neck has a 15 degree clockwise twist. The bridge is in the normal position and the nut is tipped to the right. This allows the same bow hand position but it allows the left elbow to be less tucked inward to reduce stress on the player's left arm and shoulder. The fingerboard and neck are made from one piece of spruce without a scroll to reduce weight. This will may also help reduce stress on the left arm and shoulder and makes the viola easier to hold up with less chin pressure. The goal is to make the viola easier to hold and play. I still have a lot of work to do on making it sound good.
  6. I understand the difference in power between a 22 and a 30-06 would affect projection. But what about their frequency profiles? I'd like to see a 25-06, 270, and a 30-06 all having the same powder capacity (energy) compared across the valley. 243 vs. 308 etc. high frequency crack vs. boom High frequencies are more attenuated by distance than low frequencies. Therefore when we hear a high frequency sound we automatically sense that it is coming from a close source. So some people think a violin should put out a lot of high frequencies so that it gives the sensation of being close by. To them "projection" is this close-by sensation. Other people think low end should be emphasized because it will carry better over long distances. In any case, if you're on the other side of the valley and you hear the 30-06 it means you're still alive.
  7. You're right. Maybe they should include some typical concert-goers: grey haired people who probably don't have good high frequency hearing.
  8. Many, if not all, of the frequencies of viola's various vibration modes are probably lowered and the frequency distances between them are reduced when a low stiffness flat top plate is used. This might be helpful for making small violas sound like big ones. The viola in the photo has a length of only 15.5 inches. I'm trying to get lots of resonance peaks of similar height packed into the frequency response curve with the hope of preventing either overly loud or weak notes. One goal is to get more even note loudness and color over the entire playing range. Typical arched plate violins and violas have relatively few widely spaced big resonance peaks (A0, B1-, B1+) in their lower range. Players are accustomed to that so anything that is different from this is often considered "different".
  9. The tail piece is very high which gives a real shallow string angle over the bridge which in turn decreases the downward load on the top to about 1/3 of the normal load. There's obviously no longitudinal compressive string load on the top. I'm trying to reduce stress and I exercise regularly.
  10. I should have followed the late Sam Compton's advice: "Never build an instrument that you can't buy a case for." I made a case of polystyrene foam and covered it with duct tape. Young girl viola players like it because it goes with their duct tape prom dresses.
  11. No, but I did get her card. I was quite impressed how well it worked. Almost as good as walking a puppy in a park.
  12. Yes, it is a carbon fiber rod that connects the tailpiece to the fingerboard. Some people don't like the way a tailpiece screws up their chin placement so I reversed its attachment point and got rid of the tail chord and end button. It doesn't have a bottom block either.
  13. No, it didn't play in tune. It has a bolted on neck so the string length can be easily adjusted from 355mm to 380mm in 5mm increments. At that time it was set up at 355mm and many players were missing their notes because the stop length was too long for that short a string length. I have since increased the string length to 375mm and the finger/thumb placement seems more typical.
  14. Dear Anders, I don't remember the work but I do remember discovering that it was convenient to make the sound post smaller in diameter than the f hole width. This led me to do lots of experiments in cutting the f holes wider which I did at Oberlin last year and afterward. It takes a huge f hole width increase to make a noticeable difference in sound. From this I concluded that the f hole width was determined by aesthetic rather than acoustic reasons. So, if you don't mind the looks of a wide f hole you might try bigger diameter sound posts. I also discovered that it seems to look better if both f holes are the same size. Or if you want to try a stiffer sound post while keeping narrow f holes you can use a stiffer material than spruce. I tried carbon fiber tubes with maple end pads. They sounded good but it was difficult to stick them on my sound post setter.
  15. So, you don't think Don's sound post diameter reduction experiment was valid. Why not?
  16. Looks like a good idea to me but aren't you curious to see how much thinner it can be before its wrecked?
  17. I think cutting the diameter in half would reduce its stiffness by a factor of 16 because the moment of inertia is dependent upon the diameter to the fourth power.
  18. I agree: You hit head right on the nail and gave excellent advice. Great summary, Thanks
  19. Do we have any probability experts that can tell us what the percent distribution would be based upon mere 50% chance of being new or old. (put 3 white balls and 3 black balls in a bowl and pick them out while being blindfolded kind of test). The people who got "All correct" might have been just lucky and don't know squat.
  20. A cheap and easy thing would be to try a new bridge to see if anything changes. If not, then thin the top portion of the new bridge above the waist to reduce the weight by about 0.1 g to again see if anything changes. If not, then try reducing the weight even more and so on. If it doesn't get better, remind yourself not to try any of my ideas in the future.
  21. That was beautiful! The violin wasn't bad either.
  22. What kind of tea is recommended? I assume its not green tea.
  23. I have used the maple insert with epoxy glue too and it worked well. What kind of dog do you have? Beautiful!
  24. The bridge between the string and the violin body may also play a roll. Light bridges seem to produce a krisp shorter starting transient for me which I like.
  • Create New...