Don Noon

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About Don Noon

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    It ain't rocket science... it's more complicated
  • Birthday 03/20/1952

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    Male
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    Carlsbad, CA
  • Interests
    Acoustics
    Violin construction
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    Old-time fiddling

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  1. An alternative conclusion (since A1 frequency doesn't vary all that much) is that "good" violins have a higher B1- frequency, for some independent reason. I remember Hutchins harping on some similar separation between A1 and some signature mode as a sign of good and bad; I wonder if that is where it comes from. Until I see some clear evidence myself of A1 participating in bowed acoustic output, I'll continue to be a skeptic. I haven't seen it yet. There can be other things that look like A1, such as splitting the B modes to make more peaks, or perhaps other unidentified structural modes that are relatively minor, but show up sometimes. And the idea of tuning two resonances together to strengthen them seems like the wrong direction... making the response more uneven by creating one strong peak instead of two smaller ones. Usually the "tuning together" routine is to use a non-radiating resonance to attenuate an overly-strong acoustic peak.
  2. All violins are made pretty much the same... spruce, maple, carved, glued... including Strads and Guarneris played by top soloists. The construction differences are not obvious, but some of us hear (and I guess measure as well, as Marty referenced) significant differences. Certain modern makers seem to have a knack of winning blind tone tests, too. However, if you think everything sounds about the same, then none of this matters. I tend to think that the performance differences are real, and want to understand the not-so-obvious reasons why that might be.
  3. Yes, I can certainly believe that overall dB level matters, and I'm glad others are doing this work. There is probably some other factor to "projection", most likely involving what frequency range has the dB's. But that's much more work to figure out, and still doesn't tell the luthier how to make the instrument to do any of that.
  4. There are variations in taste and requirements. Most of my relevant experience to this example is from informal trading of instruments. Many players are perfectly happy with ones I don't like at all. However, the rare cases of soloists violinists that need to play against an orchestra, often without amplification... I think they look for something more specialized.
  5. The problem comes when the things which we believe to be "out there" are proffered over and over again as fact. One last time... Although I can't show any objective measurements of projection at this time, I am absolutely positive that some instruments are clearly superior than others in this regard. I don't think it takes all that much listening experience with various players, instruments, and environments to be convinced of this. While I think it may be possible to objectively determine what makes for good "projection", it' would be a lot of effort, and mostly an academic exercise in that it wouldn't tell you how to make an instrument that projects well. And I'd rather put my time into the latter.
  6. Pardon my skepticism, but... 1) A0 and A1 are independent air resonances, and far enough apart to not have any effect on each other. I see no way that A1 could possibly get stronger just by being tuned an octave above the A0. 2) On my 3 violas that ranged from 15.4 - 16", A0 ranged from 244 - 250 Hz. An octave above that would be around 500 Hz. Although I haven't measured A1 on any of them, my violin A1's range from 464 - 477 Hz, and since violas are bigger, I'd expect A1 to be lower than that. So I don't see how you could have an A1 on a viola at >500 Hz to start with.... and then it's pretty fixed by geometry, so I also don't see how you can "lower" it. Sounds more like you might be tuning B1+ to the octave over A0, which generally seems like a bad idea (although in my experience it isn't a big deal). A good question. I measure it by close-mic at the lower eye of the sound hole, and tap on the upper bout of the top.
  7. Well, yeah. That super-skinny one was one experiment. Results have been pretty much: So I just make boring standard posts and don't worry about that dead-end.
  8. Getting them to split consistently like that (assuming it's NOT due to the tailpiece, fingerboard, or other non-radiator) seems like a desirable thing to do, in order to get a more even response.
  9. Yes, I forgot about the A1 possibility. I have never seen it show up on an impact response, and the frequency separation on my instruments has been at least 30 Hz between A1 and B1- so they would not bother each other too much. But I haven't seen everything.
  10. I do not feel trashed (at least, from any posts in this thread). In the last VMAAI competition, I sat and scored all 29 violins on tone as they were played by Cristian Fatu. It was a blind test, yet my top 10 picks matched 8 out of 10 of the picks by the judges. I leave it for others to work out the statistics, but I think it's pretty good objective evidence. Another curious result: I scored 2 violins higher than all the rest. They were ones I made (I didn't know they were mine when I scored them). They were not the top picks of the judges (but still in the top 10).
  11. I have not personally seen a fingerboard resonance do anything other than make a miniscule dent around the A0, but have never seen it do anything at all to the B modes. Not that I have seen everything, but IMO it ain't the fingerboard. There aren't very many resonances in these frequency ranges. The tailpiece/tailgut is one that I have seen. Chinrest maybe. I have often seen a split or irregularly shaped B1+ resonance, which I haven't chased down, but I think there is a body resonance in the area that can show up in addition to the "normal" B1+. For the B1-, I haven't seen anything like that.
  12. Mine definitely was an experiment, and there was no tonal "reason" other than to check out what would happen. It isn't in an instrument because it is a weird-looking thing... not because it didn't work. It worked fine, but since it wasn't better than a regular post, there was no reason to use it. Perhaps at a higher level, someone could detect a difference.
  13. I agree that the violin can be considered a multiple-emitter array at the higher frequencies, and although it isn't an isotropic radiator, I prefer to think of it as a chaotic radiator. For most conditions, I don't think that beaming is that big of a deal. For example, if you have ever switched speaker leads around to get them in phase, it's just the low frequencies that really stand out... the middle and upper frequencies sound about the same (to me, anyway) even though the phases are different and the beaming is all different... but it's too chaotic and with room reflections, it's not that significant. The one case I mentioned before... in the mid-frequency ranges... I think that the antinode separation and frequency can line up to beam to the player, which CAN be significant, and make annoying "hot" notes that are not heard at other listening positions.
  14. Taken to the extreme, there is the anorexic post, 3mm middle.
  15. Radiation ratio only includes longitudinal stiffness and density. There are many more wood properties that can be (and I think ARE) also important, like crossgrain stiffness and damping. Arching, graduations, varnish, and all those other details matter too. At one time (not too long ago) I thought radiation ratio was a very important factor (even though the math couldn't show a significant dB advantage), as there was not much else to objectively hang on to. Now I see that the math is right, and that all those other factors are far more important.