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This is very similar to Andy's thread about the B string, but I didn't want
to hijack.

I instead have a single note, the G# on my low E, that is "dead." It just
doesn't have much sustain at all. Actually, the E up at the 12th fret on
the low E string has a similar problem but not as bad. Anyway, what do
y'all do for isolated, "dead" notes???

TIA

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Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger

I've heard this happen on several high end guitars I've played and the culprit was always a bad string. As soon as the strings were changed, the problem disappeared. I would start out with the easy things like this first.

Good luck!

John

Thanks John. I probably shoulda thought of that. I never noticed the
problem before, and did recently slap some new strings on.

_________________
Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger

Mike,

Do some searches on "Wolf notes" (and before anyone has a go at me that this is only the correct term for bowed instruments, this is to help in the search). Sounds like it could be this.

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

It sounds like if you never noticed it before and you just put on new strings, it may not be a "wolf tone" resonance problem. But, if it is, G# is a likely candidate since the low G# is a common place for the main air resonance of a smaller guitar, and the G# an octave higher is a common potential value for the main top or back resonance.

If it were a resonance induced dead note, then you have a pretty high "Q" (well defined resonance) since it doesn't show up on G or F. What you'd hear is a shorter, thuddy note, since energy is transferred to the soundboard very effectively at resonance (low impedance) and most of the energy from the string gets dumped quickly. If you were to measure the amplitude of the note, you might find it odd that a dead note due to resonance will likely be louder than others, but the ear keys in on the shorter duration with fast decay, and therefore it appears to be "dead" rather than "louder and short".

I'd Say Pete is bang on correct here . That G# is a common one . My guitar had this also when I first strung it up. It has since gone , as the top's pitch has dropped I guess.

Craig Lawrence

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CRAIG LAWRENCE of AUSTRALIA
_____________________________________________

Mike,

If changing strings, fussing with the saddle, waiting for the top's pitch to drop, and who knows what else fails, you might think of looking into the Sound is Round approach.

My experience is that if a specific note is quiet, it's due to a top brace shape problem. In this case, I would examine the peaks on the scalloped legs of the X brace. I assume it's scalloped. It could also be the peak on the lowest end of the lower belly brace. These peaks all lie near or within the rings vibrated by the low E string.

As I said in my posts on the muted B string thread, pluck the note in question, the G#, and see if you can feel an arc vibrating across the lower bout, side to side, maybe an inch or two in from the lowest perimeter. The arc's center is the cross point of the X brace. If there is no vibration over the peaks mentioned, then they could well be dampening the G#.

If you can't find the arc described, try just feeling over the last few inches of the X's legs before they tuck into the kerfing, and over the lower belly brace while plucking the G# (put a capo on the neck). When I find such a spot of no vibration, I mark it with a piece of blue tape, unstring the guitar, and feel inside under the tape. Chances are there will be something about the shape of the brace that is noticeable--such as a peak or even a slight wiggle.

Whether you find such dead spots and whether you decide to reshape the peak (s) into parabolic curves, if not remove them entirely, is your choice. It is a delicate balance that is hard to define and/or guide someone else to find. But I think your problem is too specific to be a problem to be worked out on the back.

Scott

Thanks to everybody for their input.

As I said, I haven't noticed before, and I did put new strings on fairly
recently, but I also can't say that I play a lot of G#'s! Anyway, Dave, I'll
look more into "wolf" notes.

Pete, I'm hearin' what yer sayin' too. I'm not sure if I can tell that the note
is any louder, but it certainly doesn't seem to be quieter. Shorter and
thuddier are accurate descriptors.

Craig, how long did it take for that to go away for you?

Scott, I'm not totally sure that I'm grasping your description of the "arc",
but I'll feel around 'er a bit and see what I find.

It might be a while before I try the most obvious solution of changing
strings, since they're them pricey EXP's and I can live with it for a bit, but
I'll be sure to report back.

Thanks again!SniderMike39029.0180208333

_________________
Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger

Mike,

Imagine a compass large enough to put the point on the top where the X brace crosses. Then open it up so that the pencil end is about an inch or a bit more up from the very tail end of the lower bout. Draw an arc across the lower bout. This will be the ring with which the G# finds resonance.

If the guitar were completely round, like a large banjo, then it wouldn't be an arc, but a circle. I refer you to the Sound is Round diagram on my web site on the Bio and Brace Talk page. I believe that every note played finds resonance in a circular pattern, the diameter of which is inversely proportional to the frequency. The lower the note, the bigger the diameter. Visualize the soundboard as being composed of a series of wooden drummers' cymbals.

This resonant arc is not a thin line, but a band about an inch wide or a little less. Where braces pass across this arc, they will dampen a part of it if they are more massive than needed to balance the force generated by string tension at that point. The peaks that scalloping leaves are especially deadening. Just as with a teeter totter, the further away from the fulcrum, the less force it takes to balance the other side. Therefore, the further from the bridge, the lower the tension, and the less brace needed to balance it. Parabolic tapering, done correctly, automatically keeps this balance.

Charles Fox makes an Ergo model guitar whose top has only two transverse braces on the top, above and below the soundhole. This leaves the lower bout completely free to vibrate unimpeded by braces, aside from the bridge itself. If they didn't cost $15,000, I'd buy one to keep for demonstration purposes.

Normally, these arcs, or complete rings for the higher frequencies, are hard to find because the brace pattern interrupts them in a number of places, and one can only feel discrete spots or patches that vibrate.

It is my impression that wolf notes are ones that are louder than others--i.e., they howl.

Most braces are too heavy their whole length. If scalloped, the low part is usually the exception. Simply by tapping and listening, it is possible to map out the brace pattern on the top (or back) or at least find where all of the scalloped peaks are located. The soundboard above the braces sounds dead--like studs in a wall--compared with the area in between the braces. When I tune them in my re-voicing work, the braces cannot be found anymore in this manner, and a larger amount of surface area is free to make music.

Some rings/arcs are impacted more by braces than others, and end up being quieter.

Someday, the one side treble, other side bass theory will take its place along with other failed ideas, such as the flat Earth model. Except that you CAN fall off the side of a guitar...

Tap happy dude,

Scott

Dave White wrote:
"Do some searches on "Wolf notes" (and before anyone has a go at me that this is only the correct term for bowed instruments, this is to help in the search)."

We could argue all day about what constitutes 'correct' usage. The mechanism that causes the 'wolf' note that is common on 'cellos is about the same as the one that causes the 'thuddy' low notes on many guitars. The difference in the outcome has much more to do with the way the strings are driven than anything else.

It's possible that what Mike has is still a 'wolf' note, even though it only showed up when he changed strings. If he swapped gauges it's likely that the way the string is driving the top differs, and that could make an inconspicuous problem into a big one. Again, 'cellists know that switch to a diferent string gauge is one way to tame a wolf, at least sometimes.

The wolf has far more to do with the pitches of various resonances of the guitar than anything else. Usually the 'main air' resonance is somewhere near G, and, if the top is strongly coupled to it, so that it can feed string energy into the air resonance fast, that note will be loud and lack sustain. Our ears are not very sensitive to changes in level: a doubling of sound _power_ (3 dB increase) is generally a just noticable change in _loudness_. We don't notice that the sound it twice as loud; only that it lasts half as long.

It's also common for the 'main top' tap tone to be close to an octave above the 'main air' resonance. In that case there can be two more things going on: the bridge is moving a lot, so that the end of the string is not fixed, and the energy of both the fundamental and the first harmonic modes of the string are being extracted fast.

The non-fixed string end means that the pitch of the string is not securely defined, at least, not when it is vibrating in the 'vertical' direction. I've actually measured string tones that had _two_ pitches close together, which can sound like a fret buzz if it's pronounced enough. At very least, with the string end too mobile, you get a slightly 'fluffy' pitch, which can contribute to the 'thuddy', noisy nature of the tone. I think this would tend to be more of a problem with 'scalloped' braces, which allow alot of top motion in the center, than with 'tapered', including 'parabolic', brace profiles.

From time to time you can also have the 'main back' resonance tuned so close to the pitch of the main top' mode that the two will 'beat'. This can manifest itself as a sort of 'chuff' on the attack, or, again, in particularly bad cases, can sound like a string buzz. I can tell you that this can drive you up the wall until you figure it out!

The most obvious solution for a resonance that causes problems is to change the pitch of it. Since these things are often fairly narrowly defined in pitch, just getting them to fall in between notes can help. Once you get off the peak the problems are much less. Shaving braces is one easy way to do this. You can also add weight, and sometimes that's a good way to find out if the problem is indeed related to resonance tuning. Poster adhesive is a good thing to use for a temporary weight.

If too much top motion at a particular pitch is causing 'feedback' issues with the strings you can try things that 'nail' the bridge down. Adding stiffness or mass in the bridge area will both reduce the amplitude of motion, and change the pitch. You will, of course, generally lose a bit of volume, and gain some sustain, from this, but that's not guaranteed. Both volume and sustain are more complicated than they might seem, but that's normal, isn't it?

To conclude a long post: the 'wolf' was originally the pitch interval that took in the 'Pythagorean comma' in 'just' tuning schemes. It was so far out of tune that it beat terribly, and was never played. A 'cello with a wolf note can beat in somewhat the same way, and that's probably why the bowed string guys picked up on the term. So, what's 'proper' usage?

Hi Mike,
        In my case , it took a few weeks for the top's pitch to drop

_________________
CRAIG LAWRENCE of AUSTRALIA
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