Jump to content

Roger Hill

  • Posts

  • Joined

  • Last visited

Profile Information

  • Location
    Colorado Springs

Recent Profile Visitors

8038 profile views

Roger Hill's Achievements

Senior Member

Senior Member (4/5)

  1. Fool of a Took Well Dr. Mark, will you be offering and will I get to comment on a violin model constructed with the various vibration modes of the individual component parts ?
  2. Jeez. I offer an announcement from the chemistry side of the house rather than the physics side and therefor I am a behind the times reporter. No good deed goes unpunished.
  3. https://www.acs.org/content/acs/en/pressroom/newsreleases/2022/october/chemical-clues-to-the-mystery-of-whats-coating-stradivaris-violins.html
  4. “We found a mathematical argument that explains how and why this robust effect exists with any shape within this class, so that the details of the shape are unimportant, and the only fact that matters is that there is a reversal of curvature along the saw.” Location of inflection is apparently unimportant, though its existence is everything. Enjoy https://www.seas.harvard.edu/news/2022/04/physics-singing-saw
  5. Nice work, but keep in mind that the actual arch is the centerline between the top surface which you are creating and the inside surface which you will create when you do the inside surface.
  6. a better animation is found here: http://newt.phys.unsw.edu.au/jw/Bows.html
  7. Look at the spectrum of the sawtooth wave. The string is being driven not only at the fundamental frequency, but also at all the overtone frequencies. The body doesn't need to create the overtones, it simply responds to drive force of the bridge at the overtones in the sawtooth as you would expect of any approximately linear system. Again, look here: https://en.wikipedia.org/wiki/Sawtooth_wave. Again, I will accept my flogging gracefully if wrong.
  8. I think this is correct. Drive any linear system with a pure sine wave and the output will be a pure sine wave. But unless I have missed something, In which case I will be violently flogged, what I believe is that much of the spectrum of overtones results from the fact that the violin is driven by a saw-tooth wave created by slip-stick friction of the bow with the string, and that drive spectrum of the saw-tooth is rich in higher frequency overtones. See https://en.wikipedia.org/wiki/Sawtooth_wave
  9. Thanks, Don. Good explanation. The fact that I can't hear something that (for practical purposes) is not there, is probably not good evidence that my hearing is still ok. My wife may be right.............
  10. I've lived in Colorado Springs for 50+ years and had the pleasure of hearing Zukerman, Perlman, Bell, Barton-Pine, Chang and others perform with our local symphony. Our elevation is 6,000+ feet downtown where all performed. Atmospheric density here is about 1.0 Kg/M^3 compared to 1.2 at sea level. None of the violin super-stars complained of their fiddles sounding funny due to a change in A0. All of them sounded to me just like their recordings, the most likely locations for the recordings being made was in large cities, the majority of which are at sea level. If this makes a difference it will take much better ears than mine to hear it.
  11. Well, Michael, when it comes to violins, anything that pleases you just tickles me pink . Now, where I am coming from is that you could staff the physics and mechanical engineering departments of a PhD granting university with the technical talent that posts here regularly. While I can't speak for all of that talent, I think that I speak for the majority when I say that the part of violin making that we obsess over is the acoustical part, the tone. I think that most of us probably don't give a flip about the subtle curvature of the entry to the helix of the scroll, but we can get completely engrossed about the entry of the curve of the arch as it approaches the rib, something impacting tone. In my naivete, it came as a surprise to me that professional luthiers would not have tone at the top of their list (or even on their list?) of factors defining quality of a violin. Given that that is so, I can live with it. I just won't be showing anything I make to anyone in the market, and that is no great loss to the market.............
  12. Not saying that, only that the meticulous work coming out of China equals that from 18th century Cremona in appearance. If appearance is all you value, there is a surfeit of apparent quality coming out of China. I have a hard time understanding why the comments of professionals here concern only appearance. Age has a way of increasing desirability of violins, my guess is that the better new violins from China start life having appearance equal to those that started life in Cremona 250 years ago. But would any established luthier accept them as equals? If not, why not? Doesn't tone count for something in the market made by professional luthiers, numerous comments neglecting tone notwithstanding?
  13. And based upon that, it is only a matter of 250 years or so until a good quality Chinese import has value equal to today's Strads and Del Gesus?
  14. This thread seems to confirm that professional luthiers can determine the quality of a violin with only their eyes. An amazing development of their senses and skills, ears not required.............
  15. The first plot appears to my untrained eye to have a straight line from a point on the center line of the long arch just below the lower corners to a point near the start of the trough that is at the maximum distance from the start point. Or is my imagination working overtime? I believe that our famous French contributor shows that also.
  • Create New...