Wolf Tones
What causes annoying howling, whistling "wolf" tones in a violin and how do I get rid of them?
Replies (20)
What causes them? Could be.....................................................SaaaaaaTaaaaaaaN! ;)
good question!
Royce, I <3 you!!! LOL!!
Why does my instrument sometimes have wolf notes and sometimes does not? Especially when I play it fresh out of the case each practive session and then it goes away after a bit of playing?
My guess would be that your instrument has changed tuning, and therefore the wolf moved. Wolfs, if that's what they are, do NOT go away by themselves, as far as I know.
For me, it was my bow arm, as I warmed up I just naturally was making the neccessary adjustments in speed & preasure, etc. Also, if they are increasing in frequency as time goes by it's time for a new set of srings.
hope this helps.
Just about every stringed instrument has wolf tones--it is just that some are either more noticeable or in more obvious places than others. They're caused by some parts of the instrument being too thick and other too thin with the result being that the instrument fights the strings' resonance. If you have a true wolf tone (i.e. symptoms of pulsation, roughness, or jump in frequency), make sure you're not confusing rattles at certain notes caused by loose glue joints, a few ways a wolf can sometimes be treated is by removing material from the underside of the fingerboard, sometimes lighter strings, a post adjustment, or a stiffer bar can help, as well as of course a wolf eliminator.
Usually they're far more common on cellos, though less severe in instruments with more arching.
If it goes away after you've played a bit, I'd look at your technique first. Usually fresh out of the case violin muscles are not doing what they need to-until notes have been played for a while.
Latest scientific thoughts on the wolf indicate that it is caused by two major resonance points in the violin that have become too close together. Without getting into what these resonances are or why they occur (let's just say they're in all stringed instruments with varying degrees of "nearness"), the wolf occurs when these two frequencies couple with one another and create a third, lower frequency. This can be very powerful, and the vibrations actually travel backward into the bridge. If the mass and damping effects of the bow are no longer enough to absorb the vibrations, the wolf speaks.
Robert Spear-So would one loosen the hair on the bow a bit?
Royce-- I think that you will lose more than you gain by adjusting the tension of the bow because it may make playing in certain ways more difficult. It's a question of adequate mass, and changing the tension on the bow doesn't change the mass of the bow. You'll probably do better by varying the weight of the bow and the speed of the stroke if you have a problem note, or by adjusting the downward pressure (or all three in some combination). Or try a viola bow just as an experiment and see for yourself. Cellists have become masters at this sort of thing, and they can also diminish the wolf be squeezing the ribs gently between their knees when they're in the danger zone.
An interesting experiment (assuming the wolf is somewhere on the lowest string) is to bow the wolf note underneath the string rather than on top. The wolf note is guaranteed to disappear, although no one seems to know exactly why.
Hi Sean,
Take your violin in for adjustment. Wolf tones appear on all violin family instruments, but they can usually be adjusted out of violins without eliminators or major changes.
Chris
Robert- That is facinating! Thanks for your contributing that info!!!!
Robert- I tried that on my Vuillaume and you are right! Now I only wish I knew why it does that!
same question here....I have 1 wolf note which is the upper C on g string....I managed to make it sound better but it did not go out completely...very interesting topic and I'd be thankful to receive answers from any violin makers...
Not a violin maker but I have a master's in physics. :-)
It has to do with coupled oscillations. Big words, easy concept. If you hang two pendulums (pendula, but let's not be pedantic about grammar) from a metal beam and set one swinging, the other will stay pretty still. Since the support that connects them is so rigid and heavy, the swinging of one can't communicate itself to the other very well, so they behave as if they are very isolated from one another.
Now suppose you take a piece of light thread and string it from side to side, and hang the two pendulums from that. If you start one swinging, the support that connects them is now very light and flexible, and can transmit the swinging to the other one. Soon, you've got two pendulums going back and forth.
If you watch how this system behaves, you'll see something interesting -- the swinging energy will flow back and forth between the two! One will be swinging widely, and the other almost still, and then gradually, the first will slow and stop and the other will pick up speed and swing very widely, and then back again. The energy flows back and forth between the two pendulums with a separate frequency all its own.
If you search on "coupled oscillators" on YouTube, you'll turn up a bunch of teaching videos about it that will show you just what it looks like.
And it works for ANY two oscillating things that share a common support -- weights on springs, pendulums ... and violin plates. The back plate and the belly are two oscillating plates, coupled by the soundpost. Most frequencies are okay, but juuuuust the right one will cause the vibrating energy of the plates to swap back and forth through the soundpost in a way that causes a third frequency to pop up.
This is the wolf tone. It's not so much a mark of a good violin ... it's just that the best ones tend to have the most noticeable wolf tones since they sound so clean and pure otherwise. The wolves stick out like sore thumbs by comparison.
Here's a good video that shows you the way the pendulums swing back and forth at one frequency, and the "swinging energy" flows back and forth between them at another:
http://www.youtube.com/watch?v=RoSYKPTdlxs
I don't know why the CF violins tend not to have them. It may be that the top and bottom plates are so effectively ONE piece of material that they don't behave as if they are so isolated from one another. It may be that the cornices and rigid ribs of a typical violin create the problem by keeping the plates powerfully isolated at some frequencies and unpleasantly coupled at others. It would be interesting to see if a statistically significant sample of violins made in the normal shape with CF plates also had wolf notes, as opposed to the CF nearly-single-piece instruments made by people like L&C. One would need, however, a statistically significant number of instruments from which to make conclusions; one or two wouldn't be enough.
BTW, this isn't the same thing as why your A string (on a viola) and E string (on a violin) whistle. That's string misbehavior, not violin misbehavior, and it just comes from crappy bowing. Ask me how I know. :-)
" ... this isn't the same thing as why your A string (on a viola) and E string (on a violin) whistle. That's string misbehavior, not violin misbehavior, and it just comes from crappy bowing."
Not necessarily from crappy bowing - if the lower part of the first finger of the left hand very lightly touches the E-string by accident just by the nut as you bow onto it then the string can whistle, or it may "ghost" - no sound whatsoever. It rarely happens to me now, but I've still got to watch this in my violin playing because, as a cellist I have developed thickish fingers over the years.
Another cause of that sort of trouble with an open steel E (it's always the open string) is if you're bowing onto it from a plain gut A. In that case it's probably something to do with the greater differences in tensions and responses of the two materials. You just need that higher level of bow control and awareness to handle the situation, but I believe Pirastro have a wound E that is specially designed for this bare gut A / steel E combination.
Some of the older violins seem to suffer from wolf notes (no matter how good they otherwise are). More modern ones tends to be freer from them if modern calibration equipment has been used in their making. If a wolfy violin is presented to them, some luthiers will place a spot of blu-tack at various points on the belly to highlight the bad note(s). After that, I'm not sure exactly how much woodwork or other things they'll do.
I had an old English William Beard violin - sweet, rich tone, but with a terrible wolfer on the 1st B note of the A string. You know the type - really loud, mid-range harsh vibration, and far more volume than any other notes. A strategically-placed blob of blu-tack was placed on the belly, and the bad note disappeared completely. For other reasons, I wasn't prepared to have work done on it, and I traded it for another violin. A point was made :)
Depending on the instrument, it's quality, and of course its price, it can be worth doing something about these wolfers by a competent luthier, however, the old rule "you can't polish a tu** sometimes applies, unfortunately. Every violin is unique, for better or worse :)
Janise, thank you very much for such a brilliant explanation to an otherwise really complex physics concept.
To get technical accuracy back on track, it should probably be mentioned that the "coupled resonators" responsible for a typical wolf are not the top and back of the violin interacting with each other, and are rarely any two wooden parts. The coupling is between the string when played at a certain note, and a part of the violin which naturally vibrates rather violently near that frequency.
The vibration of the string sets this part into motion, and then the shaking of this part shakes the string sufficiently to upset its normal vibration pattern.
Communication between the string and the violin is bi-directional. The string vibrates and "plays" the body of the violin, but the body of the violin also vibrates and "plays" the string. To see an example of this, play a "D" on the G string (the same note as the open D), and watch how much the open D string vibrates. The played note is vibrating the bridge and body of the violin, and then these parts are vibrating and "playing" the D string.
I'm wondering if my E string issue is a wolf note issue. Firstly, I have a Wolf note high on my G string: middle C- actually when played a little flat. It sounds yarbled, a little like when you hear the beat frequency when simultaneously playing, for example, open D string and D on the G string a little out of tune. Since I saw the G string vibrating high up when the Wolf note sounded, I think it's a Wold note- the string vibrating in two parts at the same time, instead of altogether. It doesn't make a woo sound that sticks out. Again, it has a yarbled sound, for lack of a better word. On a few occasions I have heard this type of a sound on my E string when playing on the calloused part of one of the two fingers on my left hand that have callouses. Most frequently, though- and this is my E string issue -when I play with those callouses on the string, as opposed to playing on a nice, fleshy part of the finger, I sometimes hear an unsubstantial, airy sound. Then I move to the nicer part of my finger tip and it's clearer. Could the unsubstantial, airy sound be a lesser case of the yarbled sound on my E string, and be a wolf note? (I consider that the yarbled sound on the E string could be a Wolf note because of the similar sound on my G string). If so, a wolf-eliminaor might resolve this, yes?
If not, what can I do about the unsubstantial sound resulting from playing on the calloused part of the fingertip? I have already, and still do regularly, shape the callous w/ its groove with an emory board. That doesn't solve the problem. I'm actually trying to sell the violin because of this, after playing my inexpensive violin many times to see if this is just a problem with playing the E string on any violin with calloused fingers. Perhaps the problem on my E string also has to do with the low action, or the fingerboard, which has been worked on in these spots to try to correct this issue.
In terms of fingertip care, what is a properly cared for fingertip? (Note that I play perhaps 30 hours per week some parts of the year.) Should I totally remove any groove in the fingertip every night? I recall at least twice playing with a raw feeling to the fingertip as a result of using the emory board. This feeling went away quickly enough, or I just got used to it. Now I don't use the emory board unless the groove is deep, usually after a few days of playing 5 or so hours per day.
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August 16, 2009 at 08:49 PM ·
sound adjustment, different strings, and/or a wolf eliminator.
oh, and I believe it's caused by parts of the instrument resonating against each other incorrectly at that frequency (whatever note the wolf is) and the wolf is those parts fighting each other