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Anders Buen

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Everything posted by Anders Buen

  1. I have no idea. It will move naturally with the varying climate. That is the varying RH indoors, and in the flight cabin if that is the transport used.
  2. It may be worth trying a different chinrest. The Guarneri models attached over the tailpiece affect the B1+ mode to some extent, adding mass and thus reducing the amplitude of the B1+. The frequency may also move a bit. Then the wolf may move too I prefer light side mounted chinrests. Lighter strings also reduces the driving force, and thus wolf. Maybe mainly the G string or both G and D.
  3. There is sort of a balance between the strength of the B1- and the B1+ resonances. A wolf are usually found around the B1+ mode, c5-c#5-ish. If the B1+ is much stronger than the B1-, the instrument will be more likely to having a wolf. If the top/bar is made a little less stiff, and thus reducing the B1+ amplitude and increasing the B1-, the violin will be less wolfy. There can appear wolves at other notes too, even high up on the e-string. Then other fixes can be used like dampers on the afterlenght strings, putty strategically placed. Same note as wolf.
  4. At the Cleveland VSA convention in 2016, he had a remote controlled violin with wheels on it. Driving it around the stage and the floors. :-)
  5. It could sound like a violin in the highs lacking the normal lows. I think it is somewhat like the voice, you can hear and understand the whispering highs. I filled a cheap violin body with cotton. It lost some of its lows, but did still have its highs intact. Boring to play over time I guess, but could work for practicing in sensitive environments. Violins may be loud, but not like trumpets and brass instruments. The sound insulation is worst in the lows usually, but a violin doe not have much power below 250 Hz. That is fairly high and the sound insulation is usually not so bad there.
  6. Working on wood with scrapers and tools makes noise containing information from the plates or assembled instrument body, as well as the quality and sharpness of the tools. Visual and resistance clues also are feedback of course. Weighing the plates in the hands, looking at the lights going through the plates while holding them up in front of a lightsource, bending and twisting them all give information on the graduations, weights and stiffness. Much of this information may pass subcounsciously. Or the maker takes something into account and note graduations, weights or tap tones. All this information correlates, more or less. So a "graduater" will unevitably also tune the plates, a "bender" will too (I jhavent done the statistics on this one, so this is an intuition). I do not know what is better or worse if you want to go for one or two parameters to note or follow. I do not know if it matters what choice a maker does on this either. Mass and bending s fastest, tapping and listening is also fast. Mapping graduations is rather slow and tedious.
  7. No, not me. But I follow american muscle cars on facebook and sometimes seek info on other types too. Not so much in real, but on the net, youtube or the like. Good repairmen rely heavily on their ears, even in direct contact with the engine through a large screwdriver some or smething similar. many will also listen to the engine above it for clues on the "health" of the valves.
  8. Quite a lot, I think. You'll hear if it has a compressor, turbo, or not. Its number of pistons, if its a car or motorbike, if its a german or american car, diesel or petrol. If it is a high revolve engine (F1, or some japanese motorbikes) a Harlely or not, Italian two cylinder high torque motorbike. They are designed to sound different and its a part of the concept, especially for high perfomanace cars. This is taught in universities and some get their bread and butter from working on this. There is a bit of similarity between brass instrument sound generation and some car exhaust systems. An extreme example is japanese pipe cars with their "brazzy" sharp sounds, a "street made" thing. I think we rely quite a bit on acoustical clues from the car while driving. In particular in races. You'd loose a lot of information not being able to hear the engine, especially if driving a manual transmission car. Listening to high volume music makes you a less good driver.
  9. A nice route into Norwegian folk music may by music from Setesdal, as the rythm is simpler, but heavy. I used to listen a lot to Thorleiv Bjørgum in my youth. Almost like rock music in the rythm. His son Hallvard has a bit more agressive style, but very impressing I´d say. Try «Dolkaren», almost like you are riding away at full speed on the horse. There are many fine young folk musicians too in Norway. We visited the new concert house and school in Helsinki a few years ago. And I understand you have folk music students at the Sibelius institute there as well. Good to hear.
  10. I once heard JPP on TV, and they impressed! There are some festival recording with them at Youtube. Happy and equillibristic music. Swedish folk music is happy in general. Väsen is one favourtite. I also like the Nyckelharpe players who play Bach on their harps, as well as traditional Nyckelharpe music. One of my siblings father played the nyckelharpe. Son of Mats Kuoppala who tokk the Nyckelharpa into the synphny orhestra. He also made NH for kids. Of caltic music I´D recommend Aly Bain and Phil Cunningham or anything from his period with the Boys of the Logugh. My youngest half sister is daughter of Aly. Aly participated in a project with the composer, and my mothers friend, Henning Sommero and my mother who came up with the idea, I think, to arrange Shetland music for orhestra and fiddle. (My mum used top be a pro folk singer too). Henning S did the arrangements, and the BT Scottish Enmsemble «Follow the moonstone» sort of playing on the relations between nations and people around the north sea. In norway there are many fine musicicans to listen to. The music is somewhat special. I prefer to listen to my father Knut Buen, to be honest. His «Håvards draum» from early 1990ties ia favourite in scordatura and microtonality. A fine singer and Kantele player we have here from Finnskogen, Sinnikka Langeland. I think she has a finnish background. I like her tones to the poems by Hans Børli she made. He was a lumberjack, but had a quite wide and philosophical sight on things.
  11. There are a few fiddlers in here, like Don, and probably many more. I wonder how many fiddles there are (for folk playing) and violins in the world? How is the balance there in numbers or percent? Pearlman can play Jiddish fiddle music too.
  12. I think the weak back plate observation ties in with what we see for hardangerfiddles with thinner backs than most violins. Jansson also showed from measurements of a group of older violins in the Jernåker foundation that older type high arch instruments also tended to give weaker B1+. So a wolfy B1+ may be a sign of a healthy arching. The bass bar and lower f-hole thing is new to me. - Interesting.
  13. I think the B modes came from Bissinger. They look somewhat like the "Baseball seam", the B1- with the "seam" along the top and across the back. The other way around, sort of, for the B1+.
  14. I agree with Davide. The wolf becomes stronger with heavier gauge strings. Hardangerfiddles have lighter strings than violins, in general and I have never come across one with a wolf. They are sortof «baroque» still with lighter strings, I think. The pitch is usually higher as well. A violinist friend who supported while I did my master theses on vibrations in violins found wolf notes high on the e-string on a german violin I had for analysis. It also had a wolf around 400Hz, where the B1- was. It had a soft top and the B1- was stronger than the B1+ I think. Wolf appears when the minimum bow force is higher than practical for playing, I think. Usually that is on strong resonances. The Obie guys, (Stoppani) calculate the minimum bow force from bridge admittance measurements and some string parameters. These curves are similar to Ramans minimum bow curves from the late WWI time. I guess B1+ is strong in most fine violins, and I guess it is excited by playing C-C# on the G string, the heaviest one.
  15. In general the edge thickness correlates with the average thickness of violin plates. However, the edges tend to become thinner by wear and one can of course choose to keep them thick or thin at will. I do not have much experience in doing edge work on assembled bodies. But I understand that this may give changes to the body modes. I guess George Stoppani is an expert on this and his pinning of the plates before assembly may give a situation somewhat similar to the assembled violin. I think he has said that the central tinning does most. The talks VSA have run are on Youtube. One of these are with George.
  16. Ok. Mode 2 har the highest amplitude at the ends of the plate where it is flattest. I think that tilted ring angles or a higher angle cut may do something of the same, weakening the crossgrain bending stiffness.
  17. I do have a fairly large dataset of free top plates from my own practice and other sources I have come across in searches or have received for analysis. Not all have arch height given, but a fairly lage amount does. There is no clear correlation in my data between the archeight and any of the free plate frequencies, and thus not mode 2 either. However, there are numerous other factors that are clear, like the mass, the thickness and the crossgrain soundspeed. There seem to be an influence on mode 5from the arch-height, and thus it is possible that the ratio between these modes may be influenced by the arching height. I know Jim Woodhouse has said that there is about 50% stretch and 50% bending energy in mode 5.
  18. The perimeter thickness of the free plates are quite influencial on the free plate mode frequencies. This is a region where fine old insturments do see wear and the edges are doubled when necessary. I would believe the restorers would try to keep the wood as thick and original as possible, and would fill inn missing or worn wood until a given limit. I do not know if the doubling of the wood does make it stiffer than the original wood all way through. If the perimeter thickness did become thinner the tap tones wouild go down somewhat. According to George Stoppani who play with pinned edges plates, the centre thicknesses are more inportant for the pinned plates than it is for the free plates, where the perimeter seem to count more. The «Sacconi plateu» used in the end of the plates pushes up the mode 2 a little in comparison to a plate graduated also closer to the end blocks form the side.
  19. I once regraduated a cheap cornerless violin and it got a weak B1+. I added a coin to the block regions and it improved. I added corner blocks and it behaved more normal with a balance between the B1- and the B1+ Static force does not give any effect on the sound, beyond the possible small changes to the arch shape, which does influence the sound.
  20. Sure, there are more going on. There is at least longitudinal bending of the back as well. And the vibration shape is different for the top plate in the B1- mode as the activity is highest at the bridge, while it is in the ends for fre free plate mode 2. I do have a better tool for nonlinear regression now that might give more answers than just one major in statistical tests. May coma back to that later. I found a better prediction poower from using mode 2 of the free top than mode 5. Regarding the backs I use the backs on the ribs when I take out the modes. A practice better suited to regrad projects or if you build using half made back and rib assemblies as I have, as well as my grandpa. Faster, but less control. Still the mode 5 and 2 is there, but the ribs push up mode 2 and reduces mode 5 frequencies somewhat. Can be used for regression too, but will be more difficult to use for bask plate makers, if anyone would use it., anyway :-)
  21. I agree that the amplitudes are important too. Jersus A Morals experiemnts in the mid 80ties combining varying stiffness backs, tops and ribs, may be a source to look up. He measured the amplitudes at the bridge top. In his studies the amplitudes of the signature modes went down a little with increased thickness of the ribs. About 1 dB per 100% increase in thickness, if I understand the data correctly. The article on htat work can be downloaded here:https://www.speech.kth.se/prod/publications/files/qpsr/1984/1984_25_1_001-029.pdf
  22. Rodgers and Andersons article can be downloaded here, in case you want to read, see the referred fiugres and references: https://stacks.stanford.edu/file/druid:xh244qv7083/CAS_xh244qv7083.pdf You get the whole journal issue at about 25 MB size, takes a few seconds on my high speed line. The article starts on page 13.
  23. One way to try to figure out the answer to that question is by using FEA on a violin box model. Oliver Rodgers and Pamela Anderson wrote an article in the CAS Journal Nov 2001 based on their calculations. They write: Earlier work on free plates had indicated that only three of the stiffness properties of wood are important in adjusting the vibrating frequencies of plates [10 ]. These are stiffness along the grain, cross grain stiffness, and shear stiffness in the plane defined by these directions. The most sensitive characteristic was revealed to be the ratio of the cross grain stiffness to that along the grain. Calculations were made of the first eighteen frequencies (up to about Figure 5. Deflections of top at 1336 Hz (viewed from inside violin). Note sidewise deflections of bassbar and bridge. Note also that these deflections are in opposite directions. 1400 Hz) when the ratio of cross grain stiffness to along grain stiffness of the spruce (top and bassbar) was increased by 21%. All frequencies were increased by about 1.5% to 2.0% except for one at about 1150 Hz (corresponding to the 1120 Hz configuration; fig. 2b) that stood out with an increase of 3%. A similar calculation of the effect of across direction stiffness ratio reduction of 29% produced similar results, -2.5 to -3.0% except for a -6% decrease in the 1150 Hz mode. The 1120 Hz mode in the base run clearly is more strongly influenced by cross grain stiffness variations since all its nodal lines run along the grain. Calculations of the effects of changing shear stiffness gave similar results. Only one mode, in this case at around 1270Hz, seems to be affected more than others when the shear stiffness was changed, presumably because the deflection patterns of that mode were moresensitive to shear deformations. They got rather small effects, ecept for the mid frequency range. In my statistics playing around it seems as mode 2 and the B1- follow each other closer than e.g. the mode 5 of the top and B1-. I would believe that a top with weak crossgrain stiffness, e.g. with grain lines going at an angle different from 90 degrees to the gluing surface would tend to have a lower B1- frequency. Experience also tell that a slab cut back tends to give a lower B1+ frequency possibly also because the crossgrin stiffness of the back then is lower. The same is likely to happen if the back plate is thin, I believe. The nodal lines in the back plate goes like )( for the B1+ and like that for the top in B1-.
  24. The most important effect on the crossgrain stiffness, except for the grain angle, is the thickness of the plate. The arch has a rather limited effect on the free plate mode 2 frequency. More on mode 5. However, for the assembled violin body the arch may be more important, as that is a true shell construction.
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