Don Noon

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About Don Noon

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

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

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  1. Don Noon

    wood selection

    For quality, I agree that assigning percentages is illogical. You could give percentages to how much measurable sound is produced by the top vs. the back (or at least how much sound the microphone sees when it is placed there). I thought it would be interesting to compare top and back microphone measurements from my impact testing... and did NOT find more total sound from the front mic position. More high frequency, but not as much in the lower frequencies. I don't do well-calibrated tests, but I thought I would see something different. Even with that odd finding, I must say that the top does make a huge difference. My workhorse VSO has had 9 different tops on it for experiments, and there has been a huge range of results. Changing backs is more difficult, and I have never done that kind of test, so I can't say how much influence the back has.
  2. Don Noon

    A.D.'s new bench

    Without descriptions of the photographs, I can't tell whether to praise the incredible workmanship and varnish of a new instrument, or the photography skills on an old Italian instrument being restored.
  3. Don Noon

    Why arching shape?

    Or, to pulverize lord Tennyson: It's better to try something tried and true when you get tired of losing.
  4. Don Noon

    Why arching shape?

    I suppose if you don't care about the top caving in due to static load, or the tonal effect due to the influence of arching on mode shapes and frequencies, it might be nice to use a flat top and get rid of those pesky, ineffective in-plane movements. I suppose you could diddle with bracing and get a bit closer, but I think there are so many things going on here that bracing can't completely duplicate the character of an arched soundboard.
  5. Don Noon

    wood selection

    If you have any clue what the real factors are in deciding what "top quality tonewood" are, this would be a nice time to let us know . I am presuming that visual defects are not actually tone enhancers.
  6. Don Noon

    wood selection

    I notice a difference in sound in every instrument I've made, and Engelmann tends to be lower density, so there are a lot of problems making comparisons... but for similar densities, I haven't noticed any apparent difference (sample size of 1 or 2 comparable sets).
  7. Don Noon

    wood selection

    Out of curiosity, I looked at my European spruce stock, the original unprocessed densities. These were fairly randomly acquired, from various places. There's a slight bit of filtering, as a few of the low and middle density samples were used. Thus far, I haven't used any of the real high density stuff.
  8. Don Noon

    wood selection

    Unfortunately, I don't have any clear answer. However, IMO the lowest damping is an unvarnished instrument, and I don't think it really works all that well. Too rough and uncontrolled... but loud. Heavily varnished is too much in the other direction. Somewhere in between should be good. In general, the most/highest/extreme doesn't seem to be the right goal, but the best balance. (He says while trying to obtain the highest stiffness/weight wood with the lowest damping... ) OK, on second thought, maybe some extremes would be desirable for a full-on soloist violin, but then there's still the need to keep some balance.
  9. Don Noon

    wood selection

    From purely measurable properties, there is such wide variation that there is a lot of overlap. On average, Engelmann tends to be the lightest, and Sitka the heaviest, with European in the middle. I haven't made a serious instrument from Sitka yet, but for similar densities, I haven't noticed any obvious differences between Engelmann and European. If you're used to medium density European, and try to do something with low-density Engelmann, you probably wouldn't like it.
  10. Don Noon

    wood selection

    It helps to be able to improve the quality of the wood you already bought...
  11. Don Noon

    wood selection

    Marty, there WAS an attempt to do all that with the Titian not too long ago, with FEM and adjusting wood properties to try to match the known mode frequencies. The results were more than dubious, in my mind. But we do have some indications of wood properties right now, from plate weights, taptones, and signature mode frequencies. Curtin had an article on that. Nothing appeared to be extraordinary, although perhaps maybe "good" in the way of wood properties. However, damping is rarely addressed, and difficult to measure. Bissinger attempted such measurements, and as I recall, the conclusion was that internal damping was nothing unusual, but somehow more sound was produced... something similar to what I recall Schleske observing. Physically, this doesn't hang together in my mind, and something is missing.
  12. Don Noon

    wood selection

    Reminds me of another quote, not sure who I heard it from: "You can make a bad violin from good wood, but you can't make a good violin from bad wood." That's what I had in mind when I started out making instruments... to use the "best" wood. With visuals aside, that meant high stiffness/weight, and low damping, based on general acoustic theory. Density seems to be size-related, with larger-bodied instruments benefiting most from the ligher plates, and not so much for violins. Still an experiment in progress.
  13. Don Noon

    wood selection

    Sounds exactly like something Sam Z. said to me. I don't disagree.
  14. Don Noon

    Why do bridges bend?

    I heat treat all of my bridges. The few of us who have experience trying to bend torrefied maple ribs have some idea about how bend-resistant it is, so presumably bridges will be less likely to warp. I like the color, too.
  15. Don Noon

    Why arching shape?

    First: we are dealing with the vibrating properties of an amorphously arched shell made with materials with extremely anisotropic properties. Hardly simple to analyze. Second: for "answers" you need to know the questions. In the end, it's all personal opinion and preference, which means you don't have any clearly definable goals. Dollops of colored glop on fabric sounds pretty simple, but what are the answers to a good painting?