Guest Posted June 26, 2011 Report Share Posted June 26, 2011 Basically do thicker back graduations equal more projection...so many variables and no simple answer I know...but I have to ask before I stop graduating and close the box... I remember a few who have experimented with and thought that thicker grads produce better projection...How thick is the Cannone's center? Is 5.5mm in center too thick?...total weight of this back now is 145g...it is very dense Western Bigleaf. When tapped it rings F#...exactly one octave higher than the top...The top is Simeons old engleman evenly grad at 3.0-3.1 and weighs 75g... Any advice on where a safe place to stop on this back will be appreciated... -Ernie Quote Link to comment Share on other sites More sharing options...
Dorje Posted June 26, 2011 Report Share Posted June 26, 2011 My bigleaf back landed at 4.5mm in the center and weighed in at 98g...density of back was .6g/cm cubed Quote Link to comment Share on other sites More sharing options...
Berl Mendenhall Posted June 26, 2011 Report Share Posted June 26, 2011 Basically do thicker back graduations equal more projection...so many variables and no simple answer I know...but I have to ask before I stop graduating and close the box... I remember a few who have experimented with and thought that thicker grads produce better projection...How thick is the Cannone's center? Is 5.5mm in center too thick?...total weight of this back now is 145g...it is very dense Western Bigleaf. When tapped it rings F#...exactly one octave higher than the top...The top is Simeons old engleman evenly grad at 3.0-3.1 and weighs 75g... Any advice on where a safe place to stop on this back will be appreciated... -Ernie Ernie, if you have access to Sacconi's book that would be a good graduation for your violin. He gives a average of Strad's graduations. His back centers are 4.5 tapering down to 2.6 in lower bouts and 2.4 in upper bouts. Also leave the edges about 3.3 in about 20mm's from the upper and lower bout edges. The center bouts are 4mm in about 15mm's from the edge. Also you might want to take the top down to 2.8mm's or even 2.7mm's. It seems a bit heavy at 75g's. These are just my thoughts I'm sure others will have additional advice. Good luck with your violin. Berl Quote Link to comment Share on other sites More sharing options...
robertdo Posted June 26, 2011 Report Share Posted June 26, 2011 Hi Ernie You can have a look at this youtube . At 35s Sam Zygmuntowicz bends a top plate between his hands. I think more than graduations numbers it's this kind of feeling that helps. For the back graduation it's more complicated because you can't bend it this way. From all the Stradivari posters I have 5.5mm seems a little bit on the thick side and seems to apply more to some Guarneri. Quote Link to comment Share on other sites More sharing options...
David in NC Posted June 26, 2011 Report Share Posted June 26, 2011 What you do to the back does impact the belly's ability to project tone. The top can't vibrate if the back is an immoveable object for the soundpost. Too little stiffness in the back, either by over thinning or using a softer wood, would create a degree of flabiness that would absorbe some of the motion of the post, sort of like valve float in an engine. What are the consequences of a thick center at the back(4.5mm), but thin (1.5mm) in the channels? Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2011 Report Share Posted June 26, 2011 Ernie, if you have access to Sacconi's book that would be a good graduation for your violin. He gives a average of Strad's graduations. His back centers are 4.5 tapering down to 2.6 in lower bouts and 2.4 in upper bouts. Also leave the edges about 3.3 in about 20mm's from the upper and lower bout edges. The center bouts are 4mm in about 15mm's from the edge. Also you might want to take the top down to 2.8mm's or even 2.7mm's. It seems a bit heavy at 75g's. These are just my thoughts I'm sure others will have additional advice. Good luck with your violin. Berl Berl Thanks...I don't have access to that book but I have a few graduation schemes from Strad & DG from other sources... Let me ask you this please...IYO what effect would thicker than normal graduations have on tone?... The way I'm currently understanding things are the old trade violins that were shipped to the US with thicker grads have a higher or squeaker sound...if you will...I have a large collection of old-time LP's...I listen very carefully to the sound of these fiddles...most don't have a rich sound...so I assume most of these country folks who recorded on these instruments...used those type of instruments...namely the cheaper...thicker...trade fiddles. I do notice that many of the finer violins are of thin graduation...I have heard violins with thinner grads which some to my ear sounded boomy/tubby... Well...I now have the back down to 5.0mm so I'll perhaps take a little more off... Thanks Alot!! -Ernie Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2011 Report Share Posted June 26, 2011 What you do to the back does impact the belly's ability to project tone. The top can't vibrate if the back is an immoveable object for the soundpost. Too little stiffness in the back, either by over thinning or using a softer wood, would create a degree of flabiness that would absorbe some of the motion of the post, sort of like valve float in an engine. What are the consequences of a thick center at the back(4.5mm), but thin (1.5mm) in the channels? David If the back is too stiff...what will tone sound like? I've heard too thin...so I assume it's the opposite?...high and squeaky? Thanks Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2011 Report Share Posted June 26, 2011 Hi Ernie You can have a look at this youtube . At 35s Sam Zygmuntowicz bends a top plate between his hands. I think more than graduations numbers it's this kind of feeling that helps. For the back graduation it's more complicated because you can't bend it this way. From all the Stradivari posters I have 5.5mm seems a little bit on the thick side and seems to apply more to some Guarneri. Robert do know of any DG with 5.0-5.5 back grads? Quote Link to comment Share on other sites More sharing options...
Andres Sender Posted June 26, 2011 Report Share Posted June 26, 2011 Some Del Gesus: 1744 Ole Bull 6-6.5; 1743 Cannone 6.2; Carrodus 5.4-5.5; 1737 King Joseph 5.5-5.8 etc. etc. You can't prescribe this issue out of context though. The model, quality of the arch, target player type all have to be taken into account. Anyway it's easier to remove wood than put it back. Quote Link to comment Share on other sites More sharing options...
robertdo Posted June 26, 2011 Report Share Posted June 26, 2011 Hi Ernie I have the Cessole (4.8), the Wilton (4.8). For the Ole Bull, the thickness map indicated 6.5 max! For the Strad, titian (4.4), Kruze (4.4) and Viotti (3.5). You can have an idea of others Guarneri here. Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2011 Report Share Posted June 26, 2011 Some Del Gesus: 1744 Ole Bull 6-6.5; 1743 Cannone 6.2; Carrodus 5.4-5.5; 1737 King Joseph 5.5-5.8 etc. etc. You can't prescribe this issue out of context though. The model, quality of the arch, target player type all have to be taken into account. Anyway it's easier to remove wood than put it back. WOW! Thank you Andres...that's what I was looking for... That and what relationship the thicker grads have on tone...I mean with differences that far apart it must force the tone one way or another...right? -Ernie Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2011 Report Share Posted June 26, 2011 Hi Ernie I have the Cessole (4.8), the Wilton (4.8). For the Ole Bull, the thickness map indicated 6.5 max! For the Strad, titian (4.4), Kruze (4.4) and Viotti (3.5). You can have an idea of others Guarneri here. Thanks! Quote Link to comment Share on other sites More sharing options...
Melvin Goldsmith Posted June 26, 2011 Report Share Posted June 26, 2011 Hi Ernie, Most of us luthiers know this feeling of finalizing the grads! Not many violins have a back that weighs as much as 145g....but then again not many violins are all that great so don't be too worried about doing what is normal! so why not try it as is?. F# is not a bad note for your back to have and your belly seems to have quite healthy thickness and an OK note in that regard FWIW. Higher weights and thicknesses tend to work with the more streamlined archings as on some late del Gesu ...probably they can't work on a more rigid architecture such as the typical Stainer. My advice when finalizing grads is to finish the instrument with a thicker grad that feels like it could work as you have now. See how it plays...re grad the fiddle a couple of times if you feel necessary...and learn from that. You will be surprised by what you find. Quote Link to comment Share on other sites More sharing options...
Berl Mendenhall Posted June 26, 2011 Report Share Posted June 26, 2011 Ernie, In my experience, if you leave the back too thick the fiddle won't have an open sound with good volume. It might have a pretty sound but no volume, almost like muted. I'm not trying to tell you what to do but if it was me I'd forget about the trying to figure out old fiddles and just try to make the best fiddle you can with proven graduation schemes. There will be plenty of time after you've made several fiddles to try this and that. If your arching is good and you follow Sacconi's graduation advice you will make a good sounding fiddle. I don't mean to sound like it's easy because it's not. There are a dozen things you can do to screw up the sound of a fiddle. Arching and graduation are two things you have control over and are a big step in the right direction. You should really think about getting the Sacconi book. It's not outrageously expensive. I think it's one of the best books out there. Berl Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2011 Report Share Posted June 26, 2011 Thanks Very Much to all...I'm hoping I'll learn more about this in the years and fiddles to come...I'm going to finalize somewhere in the middle and go from there...and get on with it -Ernie Quote Link to comment Share on other sites More sharing options...
Melvin Goldsmith Posted June 26, 2011 Report Share Posted June 26, 2011 . You should really think about getting the Sacconi book. It's not outrageously expensive. I think it's one of the best books out there. Berl Good advice probably..It is good to have the book but also to listen to several musicians who tried Sacconi instruments. Quote Link to comment Share on other sites More sharing options...
Geoff-UK Posted June 26, 2011 Report Share Posted June 26, 2011 Ernie - you only mention the thickness at the max. What's your thickness for the rest of the plate ? The Bergonzi I'm doing at the moment is about 5.1 central spot - but around the arc of the corners its down to 3.5 or so and in the bouts anything between 2.1 and 2.7. I mostly go on weight - and try to get around 100 -110 gms. No idea why ! Geoff Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2011 Report Share Posted June 26, 2011 Ernie - you only mention the thickness at the max. What's your thickness for the rest of the plate ? The Bergonzi I'm doing at the moment is about 5.1 central spot - but around the arc of the corners its down to 3.5 or so and in the bouts anything between 2.1 and 2.7. I mostly go on weight - and try to get around 100 -110 gms. No idea why ! Geoff Hi Geoff upper & lower bout lungs are 2.7 to 2.9... to 3.0 at the middle joint and edges, corners and edges are 3.0... inside ff's are 3.5 tapering to 4.7 at middle oval spot Plate weight now is 138g...I didn't realize how dense this maple was until I went wood shopping...I'm using a neck block from another tree and it is completly different...much, much lighter and softer than the back...I think the back wood was lying in a pile of horse-dung because it is as hard as an Aubert deluxe bridge blank...where the neck wood I can leave a fingernail mark if I press too hard... I don't think I'm that far off with the grads...am I? Quote Link to comment Share on other sites More sharing options...
Guest Posted June 27, 2011 Report Share Posted June 27, 2011 I'm now wondering about the makers who use dense wood like Bubinga...and what the weight of their plates end up being and how they deal with the graduations...also how their instruments sound...... Quote Link to comment Share on other sites More sharing options...
Anders Buen Posted June 27, 2011 Report Share Posted June 27, 2011 I am not an expert on low density wood. Haven't used it enough to have direct own experiences on the matter, besides the soft lower density black alder backs we sometimes see and hear in Hardanger fiddles. Using Cannone grads on a dense maple is probably not going to work well. Some of the Ole Bull copies at the Landon exhibition in Oslo had original grads, but not low density maple wood. At least one of these did not get good scores in the listening test. Some had low density wood and worked better. I also know a maker friend who regraduated his Cannone copy using local medium to high density maple wood. Denser wood is likely to be stiffer and the B1+ mode and the B1- B1+ delta is likely to become quite large with that solution. Having said that, a thicker back tend to give stronger signature modes and some fiddles can be quite punchy with such a solution. I had a hardanger for regrad with a thick back like the Ole Bull, 6mm ish in the centre of the back. It worked pretty well after the regrad. I only regraduated the top. Good luck with your project! Quote Link to comment Share on other sites More sharing options...
Doc Eastman Posted September 9, 2011 Report Share Posted September 9, 2011 Ernie, if you have access to Sacconi's book that would be a good graduation for your violin. He gives a average of Strad's graduations. His back centers are 4.5 tapering down to 2.6 in lower bouts and 2.4 in upper bouts. Also leave the edges about 3.3 in about 20mm's from the upper and lower bout edges. The center bouts are 4mm in about 15mm's from the edge. Also you might want to take the top down to 2.8mm's or even 2.7mm's. It seems a bit heavy at 75g's. These are just my thoughts I'm sure others will have additional advice. Good luck with your violin. Berl I wonder why the Strad posters (McKenzie Strad 1694 Milanollo Strad 1728 so not show the 3.3 mm shelf (for want of a better word), that Sacconi shows in Fig 66 "Thickness for the belly and back of a violin". The posters show about 2.5 all the way to the edge, with no shelf. Quote Link to comment Share on other sites More sharing options...
Doc Eastman Posted September 9, 2011 Report Share Posted September 9, 2011 I wonder why the Strad posters (McKenzie Strad 1694 Milanollo Strad 1728 so not show the 3.3 mm shelf (for want of a better word), that Sacconi shows in Fig 66 "Thickness for the belly and back of a violin". The posters show about 2.5 all the way to the edge, with no shelf. Sorry for beating a dead horse, but I am really troubled by this difference. Looking at Sacconi, fig 60 it appears that the 3.3 mm area refers to the hight of the arch above the bottom edge of the plate, and not the thickness of the plate at that point. If this is true it would explain the difference. The thickness could be about the same out to the linings, but the height above the base of the plate could be 3.3 mm because this is where the recurve between the edge and the 4.5 mm contour is and the arch is depressed, not the plate thicker. Somebody please comment.... Quote Link to comment Share on other sites More sharing options...
Michael Darnton Posted September 9, 2011 Report Share Posted September 9, 2011 According to the US census, http://www.census.gov/population/socdemo/hh-fam/tabST-F1-2000.pdf , the average number of children in a family is .90. Personally, I don't know a single family with .90 children, and have never even seen a 9/10 child. Sacconi is like that. His charts are of his idealized 1715 violin model. There are only about a dozen 1715 violins, and I doubt even any of them measure like the charts. Violins from the other 70 or so years of his working life would resemble that even less. There are trends from one end to the other, and the Sacconi chart is a snapshot of one year. On top of that, Sacconi reports what he'd LIKE to see, not what he actually saw. I don't believe you will find even one Strad in existence, from any period, with grads exactly like Sacconi's visualization. Quote Link to comment Share on other sites More sharing options...
Doc Eastman Posted September 10, 2011 Report Share Posted September 10, 2011 According to the US census, http://www.census.gov/population/socdemo/hh-fam/tabST-F1-2000.pdf , the average number of children in a family is .90. Personally, I don't know a single family with .90 children, and have never even seen a 9/10 child. Sacconi is like that. His charts are of his idealized 1715 violin model. There are only about a dozen 1715 violins, and I doubt even any of them measure like the charts. Violins from the other 70 or so years of his working life would resemble that even less. There are trends from one end to the other, and the Sacconi chart is a snapshot of one year. On top of that, Sacconi reports what he'd LIKE to see, not what he actually saw. I don't believe you will find even one Strad in existence, from any period, with grads exactly like Sacconi's visualization. As a scientist I really understand statistics. However, I am not satisfied by your explanation. I wish Roger Hargrave, who made the measurements in the McKenzie poster (and probably others I can't obtain), would weigh in on the essential question of why he measures 2.5 mm at the edge of the plate when Sacconi shows a thickness of 3.3 mm extending from the edge of the plate to about 20 mm into the plate. It is hard for me to believe this is a result of averaging or some belief that Sacconi had. Quote Link to comment Share on other sites More sharing options...
Michael Darnton Posted September 10, 2011 Report Share Posted September 10, 2011 . . . (to quote Melvin.) Quote Link to comment Share on other sites More sharing options...
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