How to Tame Annoying Howling Wolf Tones

Cellists need not suffer tonal abuse

By Sarah Freiberg


Last week, a student of mine stopped playing to critique herself. “I just can’t make this note sound good. What am I doing wrong?”The note in question was an F# on her D string (third finger in first position), and no, she wasn’t doing a thing wrong. The problem was with the cello. Most cellos (and occasionally, violins and violas) have a “problem” note—one pitch that sounds annoyingly different from all the others. There may be resistance between the E and F# on the D string, but you’ll probably find an all-out howl when you play the same pitch in higher positions on the G or C string. The note can even have audible beats to it—sounding rather like a sick cow, particularly way up on the C string.

Meet the wolf note.

What Is a Wolf, Anyway?
Instrument maker Chris Dungey describes the wolf as “a result of the instability between the vibration of the body of the cello and the vibration of the affected string, which then serve to cancel each other out. The note has barely begun to sound when it disappears. This is repeated, resulting in a stuttering sound. The wolf note is mainly found on the lower strings of the cello. Not the result of a basic structural failure, a faulty repair job, or a misplaced soundpost, it’s characteristic of the instrument. Every properly proportioned cello has a wolf note.”

The process of amplifying the sound of the string through the body of the instrument is imperfect, and can interfere with ideal sound production. Seattle-based maker David Van Zandt says, “In a wolf tone, the air volume and the top, or the air volume and the back, want to cancel each other out. If there are two sound waves going up and down in sync the sound will be twice as loud. However, if the sound waves get slightly out of sync, the wolf note appears—the sound gets louder for a bit and then the waves cancel each other out. There is so much energy when the two notes are slightly out—so at the top of a sound wave the pitch goes up, and at the bottom it goes down.”

Fan Tao of D’Addario Strings mentions that better-sounding instruments tend to have stronger wolf tones. “There is some truth to the belief that good-sounding cellos and wolf tones go together. Powerful resonances are required for good-sounding cellos, but they also increase the likelihood of wolf tones.”

Strangely enough, if your cello is in good adjustment, the wolf can be more pronounced. As restorer Ken Meyer says, “The better the instrument is adjusted, the worse the wolf shows. When the instrument is not well adjusted, all the pitches are wobbling. There’s no ring while you play and the harmonics are off pitch. This can hide the wolves or make for just general wolfy areas. When harmonics aren’t matched, you get a range of pitches for each note, and nothing is focused.”

In that case, bring your cello in for an adjustment—make sure the bridge and soundpost are fitting properly—then you don’t have to struggle to play in tune, and also you can figure out how much of a wolf problem you really have. And if your wolf is quite present on the D string, then you should also bring your cello in for a checkup. Dungey says, “If you can elicit the wolf ‘stuttering’ on the D string in first position, the soundpost is not giving the cello enough support. Your repairman will need to reposition, tighten, or make a longer post at this point.”

Finding the optimal balance between good sound and annoying wolf is the key. Leslie Moye, a professional cellist and a cello repairman, says that “the soundpost and bridge adjustment have a lot to do with wolves. One setting of the soundpost may make a strong sound but also have strong wolf. Unfortunately, there is no perfect solution.

“You want to maximize the sound of the instrument but minimize the wolf.”

Selecting a Suppressor
Most repairmen suggest that less is more—so don’t put on a heavy wolf eliminator if you can get by with something less intrusive. Van Zandt notes, “Wolf eliminators take care of the wolf tone, but they also act as filters and can dampen the sound of the instrument. Just about any good instrument has a wolf. Any solution takes away from the voice of the instrument in one way or another to a lesser or greater degree.”

If you truly “eliminate” the wolf, according to Dungey, you will be eliminating other resonances as well. “You remove all the supporting overtones that help to color or enhance this note and other related notes. Attaching any wolf eliminator/suppressor that will directly affect a specific pitch or note could be the reason some players feel a loss of tone, vibrations, or color from their cello. The end result should be the least invasive to the whole acoustic system and still retain a high degree of success with the end user (the musician).”

A single rubber mute is one of the cheapest and easiest wolf suppressors you can use—and chances are you already have one. Since the most bothersome wolf usually hovers around fourth position on the G string, put your mute there (between bridge and the tailpiece).

Meyer points out that for any type of string-placed wolf suppressor, including a mute, you need to find just the right place between the bridge and the tailpiece to get rid of the wolf. This involves plucking or bowing on the “wrong” side of the bridge. Meyer recommends that you match the pitch of the string between the bridge and the mute to the wolf tone, or to a harmonic of the wolf. “This will get you the right position. Usually this is about three-quarters of the way towards the bridge.”

If a mute doesn’t do the trick, there are wolf suppressors that fit on one string—in that same area between the bridge and the tailpiece. The usual on-string suppressor consists of a brass tube encircling a rubber tube, held on the string by a screw.

As with the mute, match the pitch of the string below the bridge to the pitch of the wolf. According to Dungey, a wolf suppressor “works better on the C because you allow the G string behind the bridge to enhance or vibrate sympathetically with other notes of the musical scale. Plus, with G strings made smaller in diameter these days, they aren’t able to add mass (along with the suppressor) to help with the suppressing job.”

Leslie Moye prefers the New Harmony wolf suppressors devised by retired scientist turned cello-builder and cello-innovator David Bice. These are brass wolf suppressors that fit directly on the string without using either rubber or a screw to affix them, and they come in different weights (thanks to a suggestion from Dungey). Says Moye, “The New Harmony suppressors come in a choice of five, seven, nine, 11, or 13 grams. A heavier wolf eliminator gives a punchier sound on the instrument, so for a dark-sounding instrument, you might need more mass on the wolf eliminator.” (The New Harmony suppressors cost a mere $16 per weight.)

Anton Paar entered the wolf-suppressor market recently with another metal on-string contender that’s considerably more expensive (€178, available through Schubach Violin Shop), and not yet widely available in the US. This one is small but very heavy. According to product manager Siegfried Hollerer, “[Because] we keep the contacting area between mass and string very small, the influence on the resonance frequency is very narrow banded and one can filter out the wolf resonance precisely without badly influencing other frequencies—especially all overtones.”

Picking the Right Eliminator
If the on-string suppressors don’t work well for the wolf on your cello, you may want to try a wolf eliminator that affixes directly to the top of the instrument. San Francisco Bay Area cellist Paul Hale prefers this type—what he called “the German counterweight gizmo that one sticks on the top of the cello near the bass bar. Once you find the magic spot, you can have a luthier place it inside the cello out of sight.”

Tao agrees that this alternative can work well, “This involves adding a tuned resonator to the top of the instrument—typically somewhere in the lower section on the bass side. But the service of a skilled violin maker is required.”

I personally experienced this alternative: I had a Baroque cello with a pronounced wolf an octave below the usual wolf area—it was on the lowest F of the instrument, fourth finger on the C string. This note is one I used with great frequency, and I just couldn’t avoid or tame it. After trying various solutions, I took the cello to my repair person, and while I sawed away on the low F, the repairman moved his fingers around the top of the instrument below the f-hole near my bowing hand. It was like magic when he found the right spot—the wolf just plain disappeared. Then he carefully affixed a de-wolfer with putty to that exact location. While I preferred to keep it on the outside of the instrument for ease of adjustment later on, it can be placed on the inside in the same spot with a special tool. It didn’t look authentically Baroque, but it worked wonders, and it didn’t substantially change the rest of the cello’s sound. The Wolf Resonator comes in three specific ranges (D to E, E flat to F, E to F#) and costs about $52.

And, as I learned from Anner Bylsma some years ago, you can lessen the severity of a wolf tone by placing an available left-hand finger on another string at the pitch of the wolf or an octave of it.

While trying these various wolf-quieting options, keep in mind Dungey’s conclusion, “What seems like a simple attempt to tame the wolf is in fact a very complicated matter that is unique and individual to each cello and cellist.”


This article was originally published in Strings’ May 2005 issue. Products mentioned in this article may no longer be available and/or new products may have since come on to the market. Please help keep this article relevant by commenting below or by contacting us directly.