Basic question what is a wolf tone?
A recent build (D-28 copy) has a peculiarity , playing notes on the first string, starting at the 10 fret, and doing my best to use even pressure, the notes all have the same volume until I reach the F# (14th fret) and it is SUBSTANTIALLY louder, the G at the 15 th is almost "dead" compared especially to the F#.
Here's the question ..... is the wolf tone the F#, or the G? ..... BTW this guitar is now two years old.
other than surgery is there a remedy ... For the G note I really like playing the F#, it has volume as well as what I'll call overtones.
Wolf Tone
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Alan Carruth
- Posts: 1288
- Joined: Sun Jan 15, 2012 1:11 pm
Re: Wolf Tone
When I gave a talk on guitar wolf tones several years ago at a GAL convention, I just said that it was a couple between resonances that causes problems. There are lots of different resonances in an acoustic guitar, and an almost endless number of different combinations that can be troublesome. However, most of the big problems are caused by just a couple.
The biggest issue on guitars happens when the 'main air' resonance is very active, and very close to a played pitch. This is the lowest resonance on the guitar that can produce significant sound. It is strongly coupled with the top, so it can extract energy from the string quickly and turn it into sound. It usually falls somewhere between F# and A on the low E string, and if one of those notes is 'dead' and lacking in sustain, that's the usual cause.
The next strong resonance up is the 'main top' mode, which also couples well with the air and the string. It's usually somewhere around an octave above the 'air' mode, and can cause problems with the open G string if it's at that pitch. If the 'air' and 'wood' modes (which are really two halves of a 'bass reflex couple') are exactly an octave apart that can be a double whammy.
As you go up in frequency the modes get closer together in terms of pitch, and they're more likely to overlap, which is the root of the troubles. OTOH, they also tend to couple more weakly with the strings and the air, which reduces the problems. The manifestations can get more complicated as well. Sometimes you'll have a note that will sound just like a fret buzz when there is no string touching a fret. The pitch of a particular note can become unstable if it's right at a 'wolf' frequency, and notes above and below that pitch can be shifted from their expected frequencies.
Wolf notes are pitch linked, and that's usually a good way to tell if the problem you have is a wolf. A string can buzz on a particular fret, but it will always buzz on the fret even if you raise or lower the pitch. With a wolf the buzz shifts to a different fret when you re-tune. Also, you will often (but not always) have a wolf at that pitch on another string.
It can be hard to track down the cause of a wolf note, but once you do it's usually easy to fix: all you have to do is change the pitch of one of the resonances. These can change on their own; that's one of the things that makes these hard to track down. Changes in humidity, for example, will alter the pitches of both 'air' and 'wood' resonances, but in opposite directions. This makes wolf tones come and go with changes in humidity. The good news is, though, that once you've tracked one of these down, it is usually easy to fix it. If you look carefully you'll find that most good guitars have one or more wolf notes that are simply not strong enough to be a problem. These can lend some 'spice' to the sound.
The biggest issue on guitars happens when the 'main air' resonance is very active, and very close to a played pitch. This is the lowest resonance on the guitar that can produce significant sound. It is strongly coupled with the top, so it can extract energy from the string quickly and turn it into sound. It usually falls somewhere between F# and A on the low E string, and if one of those notes is 'dead' and lacking in sustain, that's the usual cause.
The next strong resonance up is the 'main top' mode, which also couples well with the air and the string. It's usually somewhere around an octave above the 'air' mode, and can cause problems with the open G string if it's at that pitch. If the 'air' and 'wood' modes (which are really two halves of a 'bass reflex couple') are exactly an octave apart that can be a double whammy.
As you go up in frequency the modes get closer together in terms of pitch, and they're more likely to overlap, which is the root of the troubles. OTOH, they also tend to couple more weakly with the strings and the air, which reduces the problems. The manifestations can get more complicated as well. Sometimes you'll have a note that will sound just like a fret buzz when there is no string touching a fret. The pitch of a particular note can become unstable if it's right at a 'wolf' frequency, and notes above and below that pitch can be shifted from their expected frequencies.
Wolf notes are pitch linked, and that's usually a good way to tell if the problem you have is a wolf. A string can buzz on a particular fret, but it will always buzz on the fret even if you raise or lower the pitch. With a wolf the buzz shifts to a different fret when you re-tune. Also, you will often (but not always) have a wolf at that pitch on another string.
It can be hard to track down the cause of a wolf note, but once you do it's usually easy to fix: all you have to do is change the pitch of one of the resonances. These can change on their own; that's one of the things that makes these hard to track down. Changes in humidity, for example, will alter the pitches of both 'air' and 'wood' resonances, but in opposite directions. This makes wolf tones come and go with changes in humidity. The good news is, though, that once you've tracked one of these down, it is usually easy to fix it. If you look carefully you'll find that most good guitars have one or more wolf notes that are simply not strong enough to be a problem. These can lend some 'spice' to the sound.
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Len McIntosh
- Posts: 63
- Joined: Sun Jan 08, 2012 7:51 am
Re: Wolf Tone
Thanks Alan, always like reading your replies, doesn't mean I understand them, but still enjoy.
I'm gonna experiment in very small increments. And I'm gonna read your reply again ... And again..
I'm gonna experiment in very small increments. And I'm gonna read your reply again ... And again..