James M. Jones Posted May 26, 2011 Author Report Posted May 26, 2011 Maybe you're right. The person whose opinions I trust most likes strength around the edges, so I go with that. I'm think'in that a strong edge would lead to more inplane movenent of the top and back resulting in greater amplitude??? Oded, wolf... I was told the wolf's den is in the area of the lower bouts ...... Right next to,on the east west axis, the lower block My thickness is 3mm and down to 2.4-5 at the 3 o'clock and 9 o'clock positions about 2.5 cm in from the edge... any thoughts?
Oded Kishony Posted May 26, 2011 Report Posted May 26, 2011 Right next to,on the east west axis, the lower block Yes, you've got it right. Which is the point I'm making, this region is very active acoustically and should not be dismissed off handedly. Oded
Craig Tucker Posted May 26, 2011 Report Posted May 26, 2011 Yes, Oh Jonesviolin, there is another plateau, a plateau of which you and most ordinary mortals are quite unaware, this plateau can be reached only through years of practice and self-denial or really good weed. Or - some button-like cactus...
James M. Jones Posted May 26, 2011 Author Report Posted May 26, 2011 Or - some button-like cactus... Carlos...Is that you ....Carlos? perhaps just a Dog..
Michael_Molnar Posted May 26, 2011 Report Posted May 26, 2011 So could "CT Castaneda" or someone else tell us whether Stradivari and his contemporaries used a "Sacconi Plateau?? On both plates? Stay Tuned. Mike
Craig Tucker Posted May 26, 2011 Report Posted May 26, 2011 Carlos...Is that you ....Carlos? perhaps just a Dog.. In an interesting aside (for another forum) - I went to see him lecture in the early 70's when I was taking an extension course in anthropology at UCLA, and he never showed, the rat!. Their excuse was that he was called off to Mexico unexpectedly. Always in character. Ok, back to the plateau...
Craig Tucker Posted May 26, 2011 Report Posted May 26, 2011 So could "CT Castaneda" or someone else tell us whether Stradivari and his contemporaries used a "Sacconi Plateau?? On both plates? Stay Tuned. Mike I have always wondered about these questions too. I don't know why, but that "plateau" has always been sort of a tenuous proposition. Did Strad or any of his contemporaries ever even use them? I have never worked on one, and I don't believe I have ever seen a photo attributed to him or any of the other golden period instruments using one either. Did the idea actually originate with Sacconi? It's amazing to me how much I really don't know about the subject.
Michael Darnton Posted May 26, 2011 Report Posted May 26, 2011 I have seen one Strad that still had it intact on the top. It's not as sharply defined as in Sacconi's drawing. I believe that many of them may have been removed by well-intended "restorers" thinking that the sound would improve. That particular instrument was so clean that the Sacconi-sighted thumbnail mark for locating f-holes was visible in the middle of the underedge of the c-bout, also. I don't know if it was on the back. I sort of doubt it, since there wouldn't be any logic for it there at all.
Torbjörn Zethelius Posted May 26, 2011 Report Posted May 26, 2011 I have always wondered about these questions too. I don't know why, but that "plateau" has always been sort of a tenuous proposition. Did Strad or any of his contemporaries ever even use them? I have never worked on one, and I don't believe I have ever seen a photo attributed to him or any of the other golden period instruments using one either. Did the idea actually originate with Sacconi? It's amazing to me how much I really don't know about the subject. If you look closely at the elevation lines it seems that they stop short just at the 'Sacconi Plateaus'. I think this is the Betts by the way.
Michael Darnton Posted May 26, 2011 Report Posted May 26, 2011 We made a habit for a while at B&F of measuring the thickness right at the edge of the platforms of the instruments we saw. That point should be the thickest spot in that neighborhood (excluding the edge) and on Cremonese instruments it was consistently thinner than other types, by a mm or more, often. When I (later) started making instruments, I got very conscious of not starting the rise of the arch too quickly at the ends, as you see from so many other schools, but you can't make the scoop come down lowest right at the edge of the platform, either--that ends up looking too lean, and weak at a vulnerable spot. I'm always fighting, though, to keep it from getting too thick there, and will change the arch slightly to accomodate that.
Carl Stross Posted May 26, 2011 Report Posted May 26, 2011 We made a habit for a while at B&F of measuring the thickness right at the edge of the platforms of the instruments we saw. That point should be the thickest spot in that neighborhood (excluding the edge) and on Cremonese instruments it was consistently thinner than other types, by a mm or more, often. When I (later) started making instruments, I got very conscious of not starting the rise of the arch too quickly at the ends, as you see from so many other schools, but you can't make the scoop come down lowest right at the edge of the platform, either--that ends up looking too lean, and weak at a vulnerable spot. I'm always fighting, though, to keep it from getting too thick there, and will change the arch slightly to accomodate that. And now you really confused me...
Carl Stross Posted May 26, 2011 Report Posted May 26, 2011 And now you really confused me... No. I'm fine.
Anders Buen Posted May 26, 2011 Report Posted May 26, 2011 If you look closely at the elevation lines it seems that they stop short just at the 'Sacconi Plateaus'. I think this is the Betts by the way. I wonder if that wide neck block influence the stability of the neck somewhat sideways. Maybe it will have an acoustic effect too?
Chad Sobodash Posted May 27, 2011 Report Posted May 27, 2011 I wonder if that wide neck block influence the stability of the neck somewhat sideways. Maybe it will have an acoustic effect too? Interesting. If it affected any mode, my guess would be B0 somewhere closer to 300Hz. I know it's non-radiating though, and I haven't really done any studies of B0. Just a hunch. Thoughts?
James M. Jones Posted May 27, 2011 Author Report Posted May 27, 2011 If you look closely at the elevation lines it seems that they stop short just at the 'Sacconi Plateaus'. I think this is the Betts by the way. Fasinating ... really, I can see how the wide neck block could greatly stablize the neck in the side to side motion, as Anders points out. So revealing my ignorance again... Chad,... the relative BO hz would rise.. yes?
Chad Sobodash Posted May 27, 2011 Report Posted May 27, 2011 Fasinating ... really, I can see how the wide neck block could greatly stablize the neck in the side to side motion, as Anders points out. So revealing my ignorance again... Chad,... the relative BO hz would rise.. yes? Well, let's break it down rather than just throw out a straight answer that I'm still not sure on. The edge of the fingerboard during B0 rocks upwards on a sharp angle, and the torso of the entire body wriggles up and down. The neck at the tip of the scroll pushes upward directly, as well. This combined motion of the neck and the body pivoting on a smaller point would cause a greater degree of potential torsional flex and instability between all moving parts pivoting on this central axis. Against a wider, flatter point these parts would be more likely to move up and down rather than bending and twisting across this point. This could be important in A0-B0 matching, since the A0 mode as a breating operation is highly torsional. Could it be that in an extreme case, this would cause a thinning and diminishment of the carrying power of the Helmholtz? Completely unsure. The following animation is a Strad belly (not sure which) moving at A0. This is all speculative, of course. I have no data to support any of this. Maybe Anders can help with that. For more information on the operation of B0 and A0-B0 matching, see Jim Woodhouse's article [link].
Anders Buen Posted May 27, 2011 Report Posted May 27, 2011 I guess experiments are needed to answer the question of how or if the wide upper block area affect modes and playing properties. It could rise the B0 as Chad suggest, but I do not believe in A0 B0 matching, as it in most cases will make the A0 weaker. The wide plateu and block might push the modes up a bit in their frequencies. The possible higher stability around the upper block might make the instrument sturdier in the neck body connection and thus stay better in tune. Some of my hardangers have had problems with that. I do not use the "Sacconi plateu" nor that wide upper block, but maybe it is a good idea? My experience is that narrow block will increase the rick for failures and open seams close to the block. Grandpa used to strengthen the end block regions in the top plates when he regraduated instruments. Sam Z also write in his article on "the Gluey" experiments that Wendy Moes and he liked the fiddle a little better with stiffneres near the upper block. I have also heard Sam Z say that Strads do tend to have such plateus, if I do remember correctly. There are many makers and restorers here that could comment on the issue with own direct experiences.
Selim Posted May 27, 2011 Report Posted May 27, 2011 I have never ever seen it used in any historical instrument of any school, only in new instruments where I think to myself, Ah ha, this bloke has been reading Sacconi Just curious, Are these new instruments are what is so called, modern Italians? Thanks for information.
James M. Jones Posted May 27, 2011 Author Report Posted May 27, 2011 Just curious, Are these new instruments are what is so called, modern Italians? Thanks for information. Or sacconi school
JohnCockburn Posted May 27, 2011 Report Posted May 27, 2011 Well, let's break it down rather than just throw out a straight answer that I'm still not sure on. The edge of the fingerboard during B0 rocks upwards on a sharp angle, and the torso of the entire body wriggles up and down. The neck at the tip of the scroll pushes upward directly, as well. This combined motion of the neck and the body pivoting on a smaller point would cause a greater degree of potential torsional flex and instability between all moving parts pivoting on this central axis. Against a wider, flatter point these parts would be more likely to move up and down rather than bending and twisting across this point. This could be important in A0-B0 matching, since the A0 mode as a breating operation is highly torsional. Could it be that in an extreme case, this would cause a thinning and diminishment of the carrying power of the Helmholtz? Completely unsure. The following animation is a Strad belly (not sure which) moving at A0. This is all speculative, of course. I have no data to support any of this. Maybe Anders can help with that. For more information on the operation of B0 and A0-B0 matching, see Jim Woodhouse's article [link]. Does that wobbly jello stuff actually tell you anything?
Chad Sobodash Posted May 27, 2011 Report Posted May 27, 2011 Does that wobbly jello stuff actually tell you anything? How should I approach this question? Do you want me to explain the importance of modal analysis in the study of violin acoustics or defend it? Or do you just want me to explain the A0 mode? Or do you want me to explain the visualization of the A0 mode and how it translates to real-world analysis? I have a rule: I do not defend scientific thought and the purpose of analytical thinking to those who don't believe in its value, because you will never convince those people otherwise. So, what are you actually looking for?
Janito Posted May 27, 2011 Report Posted May 27, 2011 I have a rule: I do not defend scientific thought and the purpose of analytical thinking to those who don't believe in its value, because you will never convince those people otherwise. Careful, Chad. John is a deep scientist. Did you miss his reference to wanting to own the Feynman books.
Chad Sobodash Posted May 28, 2011 Report Posted May 28, 2011 Careful, Chad. John is a deep scientist. Did you miss his reference to wanting to own the Feynman books. I'm not familiar with everyone on the board. You can understand how his question can be perceived as dismissive of the purpose of modal analysis and acoustic research. The "wobbly jello stuff" tells us what movements the top makes during the A0 mode, which is helpful in visualizing what structural differences will impact what areas of the belly. In this case, the torsional movement at the top and bottom of the top aids in telling us what will happen during a shift of the size of the endblocks.
JohnCockburn Posted May 28, 2011 Report Posted May 28, 2011 I'm not familiar with everyone on the board. You can understand how his question can be perceived as dismissive of the purpose of modal analysis and acoustic research. The "wobbly jello stuff" tells us what movements the top makes during the A0 mode, which is helpful in visualizing what structural differences will impact what areas of the belly. In this case, the torsional movement at the top and bottom of the top aids in telling us what will happen during a shift of the size of the endblocks. It's an idiotic caricature.
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