Chad Sobodash Posted May 28, 2011 Report Posted May 28, 2011 It's an idiotic caricature. So, you have your answer already? Then why ask the question?
David Burgess Posted May 28, 2011 Report Posted May 28, 2011 Does that wobbly jello stuff actually tell you anything? I'm seeing rather unimpressive outlines of a violin top and back. When you look at them, you see wobble-action? I had a similar experience back in the 60s...... It's a party weekend in the US, but I didn't know it was where you are. Hope you'll come out alright, man.
robertdo Posted May 28, 2011 Report Posted May 28, 2011 this diagram can only speak to someone who is used to analyse this kind of 3D animation. It's a little bit like echography or chest radio (or protein crystallography). the most important is: Would you be able, using this method, to predict or to simply see a small change in the plateau size or thickness. Would it be possible to improve the sound of a violin by modifiying some areas shown on this diagram (which implies that one can really analyse and fully understand the motion displayed here. If the answer is yes, then it's a valuable source of information not only for sound engineers, but for makers as well.
Carl Stross Posted May 28, 2011 Report Posted May 28, 2011 this diagram can only speak to someone who is used to analyse this kind of 3D animation. It's a little bit like echography or chest radio (or protein crystallography). the most important is: Would you be able, using this method, to predict or to simply see a small change in the plateau size or thickness. Would it be possible to improve the sound of a violin by modifiying some areas shown on this diagram (which implies that one can really analyse and fully understand the motion displayed here. If the answer is yes, then it's a valuable source of information not only for sound engineers, but for makers as well. The "diagram" is extremely important and must be always used in conjunction with FFT plots. By looking at those long enough one get's the warm and self assured feelings of a "research scientist". Not much else unfortunately...
Chad Sobodash Posted May 28, 2011 Report Posted May 28, 2011 this diagram can only speak to someone who is used to analyse this kind of 3D animation. It's a little bit like echography or chest radio (or protein crystallography). the most important is: Would you be able, using this method, to predict or to simply see a small change in the plateau size or thickness. Would it be possible to improve the sound of a violin by modifiying some areas shown on this diagram (which implies that one can really analyse and fully understand the motion displayed here. If the answer is yes, then it's a valuable source of information not only for sound engineers, but for makers as well. This all depends on the personal preference of the maker. That does not invalidate it as a potential line of pursuit for those interested in the subject, though. The "diagram" is extremely important and must be always used in conjunction with FFT plots. By looking at those long enough one get's the warm and self assured feelings of a "research scientist". Not much else unfortunately... I was only using it, in this context, as a visual aid for A0 for those who believe in A0-B0 matching (which I personally reserve my judgment on until after I've heard more; it's not a particular area of study, at the moment). All I'm saying is that, if you believe in A0-B0 matching, the top and bottom blocks could be something worth looking at for balance. It wasn't to be used for any degree of measurement, just illustration.
Oded Kishony Posted May 28, 2011 Report Posted May 28, 2011 modal analysis is fun to look at and can sometimes be informative. What you have to keep in mind is that lots of movement does not necessarily translate to lots of sound. I have not seen that modal analysis has been a very helpful technology for violinmakers. There is a very steep learning curve and modal analysis has very limited predictive ability. Oded
Chad Sobodash Posted May 28, 2011 Report Posted May 28, 2011 modal analysis is fun to look at and can sometimes be informative. What you have to keep in mind is that lots of movement does not necessarily translate to lots of sound. I have not seen that modal analysis has been a very helpful technology for violinmakers. There is a very steep learning curve and modal analysis has very limited predictive ability. Oded I'm thinking more of a restoration and repair context, for this. But I appreciate your point of view. I believe that everything can be understood with enough study and analytical thinking. And a greater understanding of what interests you is never a bad thing.
David Burgess Posted May 28, 2011 Report Posted May 28, 2011 I've actually spent quite a bit of time watching animations like that, at different frequencies. If you don't have a sense of how an instrument moves, aren't you compromised in being able to do anything about it? With a little mechanical intuition, it's not difficult to come up with hypothesis about what changes will alter motion and radiation, at least at the lower frequencies. It's a whole lot better than stabbing in the dark. To me, it's a useful adjunct to training, experience, folklore, questionable advice, and whatever else we typically use in an attempt to get fiddles to sound a certain way. I'll add that some pretty successful fiddle makers have been involved in the push to generate these types of animations. Could there be a connection, or is it coincidence?
Michael Darnton Posted May 28, 2011 Report Posted May 28, 2011 I more often find myself getting ideas and then looking at modes to see if the modes support the idea rather than the other way around. By the time I get around to that, if the question is related to a specific problem, I've usually already worked out a solution, so I find the modes interesting, but not particularly useful. Consequently, if the mode doesn't support the idea, I dump the mode, not the idea, because as Oded notes, not every movement makes noise. But like David, I do spend a lot of time looking at them and thinking about it, anyway. More useful to me is a more traditional concept of how a violin moves, like someone would have had 300 or 400 years ago. I did make a comment on another thread a couple of weeks ago that was inspired entirely by observing modes, but no one picked up on it. :-) It related to A0 ↔ B1+ , if I remember correctly. The other day I was reading one of Nigel Harris' little articles that relates precisely to what's being discussed here, and I *think* (he writes so obscurely it's hard to tell) that he draws the exact opposite conclusion from what I have come to empirically, and proves his position with lots of dense calculations. The main reason I don't find this type of discussion useful is that it isn't good enough to answer the question "How do you get to Baltimore?" You really to need to know where the person who's asking is standing, and how much money he has for the trip. Then there's the question of what's so great about Baltimore, anyway, that someone would prefer to go there? Violin making is a lot like that.
CT Dolan Posted May 28, 2011 Report Posted May 28, 2011 I more often find myself getting ideas and then looking at modes to see if the modes support the idea rather than the other way around. By the time I get around to that, if the question is related to a specific problem, I've usually already worked out a solution, so I find the modes interesting, but not particularly useful. Consequently, if the mode doesn't support the idea, I dump the mode, not the idea, because as Oded notes, not every movement makes noise. But like David, I do spend a lot of time looking at them and thinking about it, anyway. More useful to me is a more traditional concept of how a violin moves, like someone would have had 300 or 400 years ago. I did make a comment on another thread a couple of weeks ago that was inspired entirely by observing modes, but no one picked up on it. :-) It related to A0 ↔ B1+ , if I remember correctly. The other day I was reading one of Nigel Harris' little articles that relates precisely to what's being discussed here, and I *think* (he writes so obscurely it's hard to tell) that he draws the exact opposite conclusion from what I have come to empirically, and proves his position with lots of dense calculations. The main reason I don't find this type of discussion useful is that it isn't good enough to answer the question "How do you get to Baltimore?" You really to need to know where the person who's asking is standing, and how much money he has for the trip. Then there's the question of what's so great about Baltimore, anyway, that someone would prefer to go there? Violin making is a lot like that. Violinmaking is empirical, by nature, and this is one of the reasons I love it so. Michael, regarding the post you mention from a couple of weeks ago, if it is the one I am thinking of I remember being left with one conclusion after having read your words; which is that I, if the craft were a journey from the east coast to west, am at present totally lost somewhere deep in the forests of upstate New York. In short, you made me realize just how little I really know, and how damn far it is I have yet to go, and even how uncertain I am of which way I need to go. But, this is something I like to think of as good, as it is much better to realize you're lost, than to think you've already arrived, when you haven't even come close.
Carl Stross Posted May 28, 2011 Report Posted May 28, 2011 I more often find myself getting ideas and then looking at modes to see if the modes support the idea rather than the other way around. By the time I get around to that, if the question is related to a specific problem, I've usually already worked out a solution, so I find the modes interesting, but not particularly useful. Consequently, if the mode doesn't support the idea, I dump the mode, not the idea, because as Oded notes, not every movement makes noise. But like David, I do spend a lot of time looking at them and thinking about it, anyway. More useful to me is a more traditional concept of how a violin moves, like someone would have had 300 or 400 years ago. I did make a comment on another thread a couple of weeks ago that was inspired entirely by observing modes, but no one picked up on it. :-) It related to A0 ↔ B1+ , if I remember correctly. The other day I was reading one of Nigel Harris' little articles that relates precisely to what's being discussed here, and I *think* (he writes so obscurely it's hard to tell) that he draws the exact opposite conclusion from what I have come to empirically, and proves his position with lots of dense calculations. The main reason I don't find this type of discussion useful is that it isn't good enough to answer the question "How do you get to Baltimore?" You really to need to know where the person who's asking is standing, and how much money he has for the trip. Then there's the question of what's so great about Baltimore, anyway, that someone would prefer to go there? Violin making is a lot like that. The problem with modes is that a violin is too strong from a statics point ( it's built like a small tank ). And not a guitar, an issue badly ignored by the armchair violin researcher. Michael's example is brilliant but I won't support it with evidence - mode people will bite my head off....I'll say only that modes are great for a certain class of problems and useless for others. Most researchers seem to have this the other way round.
JimMurphy Posted May 28, 2011 Report Posted May 28, 2011 It's a shame more great sounding Violas haven't undergone Modal analysis. If scaled properly, you'd expect to see important similarities between standard modes of both Violin & Viola made by the same hand of a great maker. Jim
Michael Darnton Posted May 28, 2011 Report Posted May 28, 2011 Yes! Larger quantities of irrelevant data will surely lead to a solution!!!
Oded Kishony Posted May 28, 2011 Report Posted May 28, 2011 I'll add that some pretty successful fiddle makers have been involved in the push to generate these types of animations. Could there be a connection, or is it coincidence? Not one of the people involved in modal analysis is using it for making their instruments, as far as I know. It has sometimes been used to analyze a problem instrument with some success, but I'm not convinced that some other simpler method could not have been just as useful. I'm not advocating that modal analysis isn't interesting or of some limited use and I also love looking at the animations, but I'm convinced that modal analysis as a working tool is grossly overrated. BTW from what I've seen violas are not simply scaled up violins. Oded
JimMurphy Posted May 28, 2011 Report Posted May 28, 2011 Yes! Larger quantities of irrelevant data will surely lead to a solution!!! For me, "great sounding" would mean a Viola with both clarity & rich harmonic content [and for David ... a little 'Janis Joplin' under-ear noise too ]. To subject any other subpar sounding Viola to Modal analysis could indeed be a waste. Jim
JimMurphy Posted May 28, 2011 Report Posted May 28, 2011 BTW from what I've seen violas are not simply scaled up violins. Indeed. Seems as if those Cremonese were attempting to scale instruments using string tuning frequencies as their basis. Jim
Carl Stross Posted May 28, 2011 Report Posted May 28, 2011 It's a shame more great sounding Violas haven't undergone Modal analysis. If scaled properly, you'd expect to see important similarities between standard modes of both Violin & Viola made by the same hand of a great maker. Jim You'll see A LOT of similarities. Basicaly anything violin shaped will be similar as long as it's not made out of butter or marmelade. Otherwise from plastic to steel they'll all look the same. ( and the steel ones will "perform" better than wood ).
Anders Buen Posted May 28, 2011 Report Posted May 28, 2011 Not one of the people involved in modal analysis is using it for making their instruments, as far as I know. It has sometimes been used to analyze a problem instrument with some success, but I'm not convinced that some other simpler method could not have been just as useful. We have seen examples of modal analysis been in use in making. One example is Martin Schleske, another one is George Stoppani. George had a copy of the Vieuxtemps at the last Oberlin violin acoustics workshop that had quite similar acoustical properties to the real del G. He would not have been able to do that without the information he has gathered from it using modal analysis. I use it now in my making, it is just a different way of looking at modes that can be heard for the plates free or on the ribs, or may be found using different methodes, e.g. Chladni or just strategic holding and tapping (my most used method). In Stoppanis software there are some possibities for calculating where the beding energy and effects of thinning is expected to affect the modes the most. There are aslo abilities to calculate how much breathing between the plates each mode posess, and George now also are able to monitor the interior air modes and how the modes radiate sound in the near field. Interesting, at least for educational purposes. I think information on how the plates move in relation to each other is relevant information for me (relavance is always in relation to a context and who are involved). I am expecting to see why sometimes the B1+ mode becomes very weak in some hardanger fiddles by using modal analysis. The plates should move too much in phase. The analysis does not solve the problem, but it can help explain it, so changes in designs can be made to improve. (Plates with good violin archings does not have that problem, so it may be related to the arching shape of the top plate). I also think modal analysis can be a very powerful tool in determining what moves where the sound radiation is strong in the range beyond the signature modes. One of the main problems with the method is that it is pretty time consuming. So makers that does not use it should be happy because they have more time to make instruments than those using time on modal analysis, improving the competition power for them. :-)
Carl Stross Posted May 28, 2011 Report Posted May 28, 2011 So makers that does not usie it should be happy because they have more time to make instruments than those using time on modal analysis, improving the competition power for them. :-) I could not've said it any better...
David Burgess Posted May 28, 2011 Report Posted May 28, 2011 The problem with modes is that a violin is too strong from a statics point ( it's built like a small tank ). And not a guitar, an issue badly ignored by the armchair violin researcher. In what way is a violin too strong, and how is that a problem with modes? And I don't understand your comparison with guitars. Could you explain? Also, who are the armchair violin researchers to whom you refer, and what are they ignoring?
David Burgess Posted May 28, 2011 Report Posted May 28, 2011 Not one of the people involved in modal analysis is using it for making their instruments, as far as I know. That's surprising to read, Oded, because you've talked quite a bit about the form of modal analysis you use yourself (string reciprocity). We have seen examples of modal analysis been in use in making. One example is Martin Schleske, another one is George Stoppani. George had a copy of the Vieuxtemps at the last Oberlin violin acoustics workshop that had quite similar acoustical properties to the real del G. He would not have been able to do that without the information he has gathered from it using modal analysis. I use it now in my making, ... And these are just some of the people who are public about using it. From conversations, I know there are others who use it in various ways. They may not talk about it, any more than they talk about their varnish process.
Oded Kishony Posted May 28, 2011 Report Posted May 28, 2011 And these are just some of the people who are public about using it. From conversations, I know there are others who use it in various ways. I remain skeptical. Is modal analysis being used for special cases like tonal copies (Schleske and Stoppani)or as a routine working tool? And I believe that there are simpler more direct ways to achieve the same ends. Such as Oliver's 'mode sniffer' a relatively simple technology with lots of potential. They may not talk about it, any more than they talk about their varnish process. ....and then there are people who like to tell stories to impress their friends Oded
~ Ben Conover Posted May 28, 2011 Report Posted May 28, 2011 The Sacconi thing tends to make the ends of the plate thicker, I think it's what was taught at Newark. Strad seems to have used this method, along with sturdy block sizes etc. Before gluing the ribs to plates I use the sanding board to make sure the plates are totally flat. My new sanding board is very flat and big enough for Cellos.
Michael Darnton Posted May 28, 2011 Report Posted May 28, 2011 Anders, have you considered regarding the diminished B1+ the possibility that all those strings have preloaded the bass side of the bridge so much that it is pushed that side of the top up against the limit of flexibility like pushing a swing againt the wall? How about moving the post inward quite a bit to let it hold more of the weight? Or a narrower bridge? Maybe a larger bar with even a bit of spring, would hold the top up a little more, freeing it up? That is the order of things I would try, anyway.
Carl Stross Posted May 28, 2011 Report Posted May 28, 2011 In what way is a violin too strong, and how is that a problem with modes? And I don't understand your comparison with guitars. Could you explain? Also, who are the armchair violin researchers to whom you refer, and what are they ignoring? 1. It's too strong from a static point. 2. Guitar gets pinched once. Violin all the time. 3. Too long a list. But I'd start with Carleen Hutchins. Basicaly anybody with an undergrad level of maths and physics who tries to solve a problem without being able to precisely define what the problem is. The armchair violin researcher goes around this by splitting the main problem into many useless subproblems and solving those. That goes nowhere. Let me put it this way : it's STUPID to tune a fingerboard with 1 gram weight and then hang your arm on it. ( Does it ring a bell ? )
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now