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Everything posted by JimMurphy

  1. On the +side, continued acoustic research is getting us much closer to understanding stringed instrument 'design' principles [both pre- and post Cremonese design]. It's understood many people don't care about these things. And yet, Stradivari himself made violin design changes still copied today ~300 years later. Think about that a little bit. I wish you all well! Jim
  2. Oh no. That's a purpleized pic of Stradivari's Messiah. I call my icon "The Purple Messiah". Jim
  3. Don't worry, Anders. The original Italian genius didn't mess-up that much. Be assured, I haven't made anything shaped like a Rivinus fiddle. Jim
  4. "Functional Art", Oded. IF a violin's 'objective' is to project a certain blend of frequencies - and no one measures it - you're pretty much limited to finding only what you're looking for. We're NOT talking about determining which is the best violin per se. We're talking about objectively measuring 'how well' a violin performs its task. Incidentally, measuring for fifths is merely a suggested starting point. Jim
  5. The main thing that bothers me about Dunnwald parameters is they're based on 'subjective' data from a group of "good" fiddles - rather than based on pure acoustic string theory. Just sayin' ... Jim
  6. At least I'm sharing ideas about possible 'objective' testing methods. Jim
  7. Hey, C'MON!! Let's hear some glissandi or even long drawn-out notes to quickly identify acoustic weaknesses in that funky-shaped fiddle. Jim
  8. Thanks for your interest. At this time, I'm not going to show pics or release any recordings at least until details of an objective testing protocol get worked out. There are a LOT of 'copyists' out there, ya know! Jim
  9. Anders, You seem like a technically openminded person and perhaps one more interested in objective testing for comparing violin sound quality. Let's say you wanted to 'objectively' measure how well two violins generate and project frequencies in a perfect fifths ratio [3:2]. Where would you position the mic(s) and what other equipment would you use to narrow your measurement to fifths only? Also, would glissandi be a sufficient method to exercise each violin?? Thanks, Jim
  10. Oded, Sounding "good" is a pretty subjective term.
  11. You can do that. In reality though, ALL the curves act together to produce and project high quality sound. Jim
  12. "To see things in the seed, that is genius." ~ Lao Tzu

  13. Complexity is made of simple things.

    Violins are very complex.

    It's all so very very simple. :)

  14. The '3D set of curves' includes both arching & grads of course. Which acoustic test(s) would you consider adequate to "prove" a significant advance in violin sound projection? This is a very simple question. Jim
  15. Other than 'subjective' evaluation, modern research has NOT produced an 'objective' testing protocol to evaluate violin sound. IF they have, please direct me to the documentation detailing these test methods. Thanks, Jim
  16. While modern research has obsessed over corpus resonant modes and statistical analysis, the best 'evidence' IS the '3D set of curves' themselves we think was first used by Andrea Amati in violin design and 'copied' and/or tweaked ever since [by Stradivari himself too with refinements]. The '3D set of curves' literally shape the frequency response of any instrument. Change the curves [including f-hole shape and position] and you change the sound. The "proof" will be a violin, viola, etc whose sound and projection qualities far exceed the best so far. I'm open to suggestions for how the acoustic experts should 'objectively' measure and identify such advanced sound qualities. Jim
  17. I do have a definite theory and we're 'discussing' things right here rather than 'publishing' explicit details on a public forum. With all due respect Bill, these modern theories based on corpus resonant modes and "statistical analysis" of measured dB response on "good" fiddles [Dunnwald] haven't exactly solved the mystery of Cremonese instrument design and certainly have not led to any significant breakthroughs in producing much better violins or projecting great sound to a listening audience. Being that Cremonese chose to tune violin in fifths, it may be prudent to 'objectively' start looking at phase relationships between 3:2 frequency ratios. It may very well be "circle of fifths", for example, meant something entirely different to some 16th century Italian genius than to modern acoustic researchers. Jim
  18. Music is really all about "timing". Frequency is about timing. Phase is the timing between separate frequency waveforms. Armed with a Frequency of Notes chart and a special math/geometry-based '3D set of curves' [or "acoustic model"] tying distance vs time relationships together, a 16th century Italian genius would have all that's needed to 'organize' played string frequencies and phase relationships as well. At least one person had the math chops to design the whole family of classical stringed instruments. Back then, "phase" had nothing to do with analyzing corpus resonant mode vibrations. Jim
  19. In violin, frequencies get blended in such fashion [frequency separation] that different frequencies travel at different acoustic particle velocities. "Phase" in bowed strings simply refers to timing relationships between individual component frequency waveforms and for the composite waveform as well. I think part of what's missing from current violin theory is neglecting acoustic particle velocity differences in the Sound Intensity equation: I = pv, where "p" is sound pressure and "v" is acoustic particle velocity. Not "evidence". I think though they were simply attempting to control phase relationships between bowed string frequencies and projected violin soundwave(s) using math/geometry. Jim
  20. Yes. Describe a "hole" in my theory [compressed & rarefied air] and I'll attempt to fill it. To date, no one has offered anything other than a 'subjective' listening test. How would that prove to you there's a working 'Model' with clear correlation between string tuning frequencies, resonant modes, and great sound which gets projected? [i'm saying things don't correlate with existing Cremonese 'Models' 'cause they messed-up on their geometry proportion] And bear in mind as well, I'm willing to submit both Violin & Viola just to show my strong acoustic theory incorporates appropriate 'scaling'. Jim
  21. For the benefit of MN, please briefly describe how current theory says lower frequencies get radiated. Thank you. No. This is why Oded said, "Please...anyone who has any insights in this,feel free to contribute." He really wants to hear others' insight. Jim
  22. I gets it, David. The establishment recognizes holes in their own theory about how violins really work and doesn't fully appreciate someone coming out of nowhere to challenge their collective mindset. Somehow, I managed to immediately rule out space aliens doing the work of 'man' though. Any work on your end for possible 'objective' testing protocols rather than 'subjective' opinions? All I want to know is 'how' conclusions will be made when youz guys hear a new benchmark great-sounding instrument. Jim
  23. Perhaps the theory on how lower frequencies get radiated is not quite how things really get radiated. Food for thought. I didn't and wouldn't even suggest "phase = dB". I think the whole underlying theory about mode resonances and radiation is not what 16th century Cremonese had in mind. We'll see if someone else attempts to answer your simple questions about violin 'model' and phase canceling. Jim
  24. To me, when phase relationships are out of balance, then you get dB imbalances, i.e., too high or too low in the wrong places. We simply have opposing views on what creates violin timbre. 1. That's what has been only 'observed' on the relatively few violin models tested. The violin 'Model' should be one where mainly corpus twisting is responsible for projection. 2. No. If however your arching & grads where more in proportion [for the instrument is really like a 3D map of distance vs time relationships], then there wouldn't be all that wasted corpus movement. I'm saying '3D proportion' controls phase relationships. Jim
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