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tous ces articles je les ai consultés mais aucun n'a donné une réponse précise comment solutionner le problème; on n'a pas à notre disposition de moyen ou de matériel adéquat pour le faire dans de bonnes conditions et surtout de ne pas détériorer nos précieux instruments
Comme expliqué dans les différents sujets, le problème dépend de la construction de la guitare. Tu ne trouveras pas de solution universelle, sinon tu pourrais revendre le truc quelques centaines de millions de dollars aux grandes marques... ^^
Qu'est-ce que tu essayé et qui n'a pas fonctionné ? Es-tu allé voir un luthier ?
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-Régler les cordes plus bas peut aider à diminuer cet effet "redondant". essaye en mettant un sillet de chevalet le plus bas possible même si les cordes sont alors trop basses et frisent, ça coûte rien. si ça marche pour le son et que tu veux garder une hauteur de cordes "comme avant" il faudra demander à un luthier de rectifier l'angle de manche en reprenant la touche donc le frettage !
Le but étant de tirer plus bas au chevalet tout en gardant une hauteur cordes/touche inchangée.
-Sinon, il faudrait retravailler le barrage ... en l'occurrence augmenter la rigidité transverse, mais ça demande un détablage !
-Je ne vois pas d'autres solutions ...le manche intervient aussi dans cet emballement en G# de la table, s'il est rigidifié ou au contraire allégé, ça peut réduire le pb!
Ceci dit il n'y a pas de "recette" toute faite, à chaque guitare faut trouver le bon "truc" et ça c'est du ressort d'un bon luthier .
http://www.guitareclassiquedel(...)20441 Citation:
Généralement, les luthiers placent ce loup autour du sol dièze car cela paraît le moins gênant là-bas.
La seule vraie solution est de s'accorder plus haut ou plus bas, effectivement.
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Le phénomène existe sur à peu près toutes les guitares. Il suffit de prendre la tienne et tu trouveras b ien vite la ou les notes affectées. La corde réagit beaucoup plus vite et s'arrête de vibrer aussi beaucoup plus vite, donc plus d'impact mais moins de sustain. Le phénomène est généralement moins audible sur les guitares qui sonnent peu, mais il est visible et audible.
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The wolf tone will be more related to the soundboard design (thickness & bracing) as well as the body volume and sound-hole. Other than altering one or several of these, it will be difficult to rectify the wolf tone as you describe. Eliminating wolf tones and creating a "balanced" instrument is a pursuit of guitar makers.
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Wolf notes are the result of strong interactions between resonant modes, whether of the string, the air or the wood. In the most likely case, when you get a strong resonance in the structure or the air that matches a note you're trying to play, you can get a wolf if the conditions are wrong. That's what happens on the 'cello. Wolf notes are more of a problem for 'cellists because the string is bowed: we tickle the wolf and walk away when we pluck a string, they tie it down and torture it. On the guitar the usual 'wolf' notes are caused by a strong resonance of the top or the air (or, more likely, the two working together, just to make things more complicated!) at a pitch you are trying to play. These often occur right around G on the low E string (~98 Hz) and the open G string pitch at ~196 Hz.
The lower one is the 'thuddy G', fabled in song and story. The top extracts the energy from the string and turns it into sound very quickly, so you have a note that's twice as loud for half a long. The one in the range of the open G string can do the same, and, of course, if you have both of those pitches matched on the same guitar G notes become really problematic. The exact pitch of both of these varies, of course, and your F is certainly within range.
Either of these can also cause the sound to 'warble', due to some tricky interactions with the string. If there's a 'tap tone' on the back as well that matches the upper resonance things can get really strange.
The first thing you need to do is determine what's causing the problem. This can be the hard part. One weapon that's really handy is poster adhesive: sticky clay-like stuff that's used to hang papers up and deface walls in college dorms. It's better than modeling clay in that clay has mineral oil in it, which can leach into wood. The object is to stick a wad of stuff onto an active area of the resonant mode, which drops the pitch due to the added mass. When you get the pitch out of range of the played note, the 'wolf' should go away.
Sometimes a good way to fix this sort of thing is to alter the low 'air' resonance that couples with the top and helps determine the pitches of the modes. You can do that by covering part of the sound hole.
Once you find an effective spot the thing is to see how little added mass or sound hole restriction you can use to just fix the problem. Then you can figure out how to get the same effect in the most elegant way. For example; if adding five or six grams of mass to the bridge works, you might try switching from plastic to bone bridge pins. If some mass placed over a brace on the inside of the box works, maybe shaving that brace down a little to reduce the stiffness will have the same effect.
One caveat: wolves can come and go. Despite what Bob Taylor says, guitars _do_ 'play in', and sometimes that makes enough of a difference to eliminate a wolf. Even changes in humidity can alter wolf tones, which can make finding them frustrating! When all else fails, a heavier bridge might just do the trick by itself. You'll lose some power, and gain some sustain, and that might not be what you're after, but nobody likes a wolf, and it might just be worth it.
http://www.acousticguitarforum(...)00574 Citation:
My sympathies to you...I know this can be maddening trying to source the problem. Currently having similar issues with a new Larrivee; D string 4th, 5th & 6th frets F#, G & G#. Driving me crazy, too. Literally been through every imaginable "fix", from strings, nut, saddle, set-up, check this, check that...you name it and it's been tried by myself or various professionals. And it's not the infamous "wolf tone".
Slowly coming to the conclusion that it's just part of the guitar's personality, and hoping it fades away with maturity. Finger pressure on the top, below the bridge, partially stifles the non-musical noise brought forth when fretting those positions. I love the guitar, by the way, and wouldn't think of parting with her.
http://www.acousticguitarforum(...)+wolf Citation:
There are a number of different 'wolf' notes that can appear on a guitar, but that one in the low range is the most common. It happens when the 'main air' resonance is strong, and is pitched right on a played note. We call this an 'air' resonance because most of the output at that pitch is from the air flow at the sound hole, but the top moves a lot too. There are a couple of ways to think of it physically, but the bottom line is that the guitar extracts the energy from the string and dumps it into the air as sound very quickly, so you have one note that's twice as loud for half as long a time. Our ears aren't very good at detecting the volume change, but we sure notice the lack of sustain.
The only real solution for it is to alter that 'air' resonance so that it's not as strong, or falls between played notes. The most direct way to do that is to change the size of the sound hole. Making the hole larger (or adding a 'port') should move it up in pitch, reducing the diameter of the hole, or adding a sleeve, will drop it.
The easy test for this is to cut a strip of paper an inch or so wide, tape the ends together to form a ring that will just slide into the hole, and fix it in place. You could experiment with the width of the strip (the depth of the sleeve) to see how deep it needs to be to move the 'air' pitch down enough to cure the problem. Even simply covering part of the hole with something like foam core board can help.
There is a product called an 'O-port', that fits into the hole that does much the same thing, but more of it. Somebody sent me a couple to experiment with, but I have not had time to do much. 'Feedback Busters' would also work, but the cure might be worse than the disease. OTOH, you could cut out much of the grill work on one, and just use it as a sound hole size reducer.
An indirect approach to a solution involves shaving the _back_ braces. This _can_ (but may not in every case) lower the 'air' mode pitch. A lot depends on the guitar here, and, since it will certainly void the warranty, it's not always a good option.
Anything you do that will solve this problem will alter the sound of the guitar. It may get better, it may get worse. Try the easy and non-invasive stuff first.
http://69.41.173.82/forums/sho(...)57677 Citation:
One thing that might help would be to go to a different string gauge. One of the issues with woolves is the 'impedance match' between the strings and the bridge; if it's too close you will get more wolves. Since it's harder for you to alter the bridge impedance, changing the strings is one thing to try.
The two resonances that usually cause problems down around F# on the low E string are the 'main air' which is often close to that pitch, and the 'main top', which is often an octave or so higher. When they're exactly on octaves, and both at the pitch of a played note, you can get some really dead tones. The back can also be a contributor, if that has a resonant mode near the 'main top' pitch.
The way to check it is to alter the pitches of those resonances. The 'main top' and 'main back' pitches are actually the two parts of a 'bass reflex couple', so you might not fiind it easy to alter them independantly. Still, it's worth a try.
The 'main air' pitch is related to the 'Helmholtz' resonance; the sort of thing you get when you blow across the mouth of a wine bottle. Changing the size of the soundhole will alter that pitch; try taping a piece of card stock on to cover part of the hole, and see what happens.
The 'main top' pitch is more a function of the mass and stiffness of the top, and the bridge is a big player in both parts of that equation. Adding some mass to the bridge, by using poster adhesive, for example (DON'T use modeling clay!) will alter that resonant pitch.
As always, do one thing at a time.
If the back tap tone is higher that that of the top you might have some luck by tuning the back down. To hear the top and back tap tones clearly you have to cover the hole so that the 'main air' resonance won't mask the higher pitched top and back tones. If the lowest pitched back tap tone is, say, no more than a musical third higher in pitch than the top tone you might try adding some weight to the back to drop it's tap tone pitch. This will allow it to work more easily with the top, and can alter both the 'main top' and 'main air' pitches.
I'll note that, while this is certainly a 'defect' in terms of the instrument's utility, it's not the sort of thing that factories can deal with or plan around: from their point of view it's not something that's their fault. Wood varies a lot, and the resonances of two guitars that are 'identical' can thus be quite different. There are ways to check this, but they take time and effort, and the extra money they'd have to charge would price them out of the market.
http://69.41.173.82/forums/sho(...)57677
