Abnormal resonances - Page 4

BrickGlass · #46 08-30-2016, 02:30 PM

All you guys saying over and over how it must be his technique. Unreal. Let's give him the benefit of the doubt. He has been playing for 40 years. I've had the same problem, Paul McGill wrote a great article about it. Heck, in my thread from a few years ago I even was given info about a person working on their PhD that wrote their thesis statement about this issue. Info can be found here:

http://www.classicalguitardelcamp.co...510841#p510841

and here:
http://www.classicalguitardelcamp.co...litude#p822810

I understand that some things can't be clearly understood because they haven't been experienced by us personally. Are you guys going to tell Paul McGill that he just has bad technique or that he has no understanding of what he is talking about? Paul perfectly describes the issue right here for those of you who may have missed it:

"I had a classical guitar made by a notable maker in my shop once that would not stop buzzing. The frets were accurately aligned, and still it buzzed. This guitar was very lively and had great oscillation of its strings. After much time spent studying the problem it became clear that the noise disappeared if the note was played with the finger depressing the string right on top of the fret. If the finger was moved back even an 1/8th of an inch, the buzz reappeared. The strings had so much amplitude that the strings would accelerate right off the fret, causing a buzz even though everything was properly aligned. I raised the action, the buzz got worse. The owner said he liked bass wire on his guitars, so I installed huge bass wire in an attempt to eliminate the problem. I was skeptical, but after installing the larger wire, the noise was greatly reduced. It was still there if the player wasn't careful, but it was manageable."

I'd love to be able to help the op, but I think it is quite clear myself that technique is very likely NOT the issue. Let's move forward assuming that technique isn't the problem and give him, Paul, and me, the benefit of the doubt that this is an actual problem, and that it is very odd.

Howard Klepper · #47 08-30-2016, 05:01 PM

As I said in my first post, all that has been described so far points to frets that are too low, so that there is not enough downward force on them when fretting to stop the string unless the finger is close to the fret. There is nothing mysterious about this. It can be helped by keeping the fingers close to the frets, but I would not fault the player's technique as if that were the primary problem.

BTW, Howard Wright's PhD thesis never talks about too-low frets or demonic guitar buzzes. And while I have a lot of respect for Paul McGill, I think he is wrong in attributing the problem on the guitar he described to an extraordinarily large oscillation of the strings peculiar to one guitar. It is possible that if a note is strongly coupled to a main guitar resonance, the string's excursion would be greater than the norm and the horizontal string displacement greater than the vertical, but that would be very brief, and only at one or two notes, while he seems to describe a problem all over the neck, and that it was a sustained buzz. The problem he describes can be explained by frets that are too low.

BrickGlass · #48 08-31-2016, 01:38 AM

Howard, if the problem on the guitar discussed in Paul's comments is the frets being too low, why then is the problem only reduced but not fixed completely when Paul installed bass fretwire? You aren't going to get much bigger frets on a guitar, yet this only reduced the problem. It still existed, but was now to a manageable point. If the problem was too low of frets, why would bass fretwork not completely eliminate the problem? Paul mentions the oscillation of the strings. That is what was going on with my Cervantes. Some of the notes would literally just cause the string to vibrate like mad, to the point of a strange buzzing sound occurring. The string even looked abnormal as you watched it vibrating, almost like it was vibrating too much.

Also, if it is bad technique on my part :roll eyes:, why then does it not do this on every nylon string guitar I play? I would describe the issue I was having with my Cervantes in an almost identical fashion to the op. I've literally played hundreds of nylon string guitars over the years and I've owned quite a few. Shouldn't it be apparent on all/many/some of them if it has anything to do with technique?

Rodger Knox · #49 08-31-2016, 10:55 AM

Is it possible that this is some kind of neck resonance? I realize resonance problems are usually pretty frequency specific, and this problem doesn't seem to be. I also considered that it may be a longitudinal resonance of the string (aka zip tone), but Mr. Carruth has been contributing to this thread and I'm sure he would have mentioned it if it was a possibility.

Me&MyGuitar · #50 08-31-2016, 12:03 PM

Update.
Experiments were going on at lutihier's lab while we were discussing.

Last tries:
- A single steel 4th string was set up to pitch instead of a nylon, aaand....no buzz, no double tone but a clear tone.

- A single nylon 4th string was then set up to pitch, but instead to be tied it was fixed by simply three knots acting as a ball end
Aaaaaaaaaaaaand.......no buzz, no parasite tone, but a clear holy blessed note.

Still can't believe it's true, I'm waiting for further confirmation.
But thinking of it, I could......no no, I'll let you think about the possible explanation.

Alan Carruth · #51 08-31-2016, 12:10 PM

A lot of bandwidth is expended on the break angle over the saddle: how much is 'enough' and so on. This seems to be the same thing at the other end: not enough break angle over the fret. You get more break angle at the fret by playing closer to it, or using higher frets, or scalloping the fretboard. Since playing on the frets helps it's likely that higher frets would too.

The 'zip tone' came up in reference to this same problem on another list. I don't think that's it. If it were it would be unlikely to show up on more than one string, and the usual offender on Classical guitars is the D string, not the A. Still it is possible. Changing to a different brand or tension of string might help if that's the case, Or it might not. Playing right on the fret would tend to damp the zip tone.

Me&MyGuitar · #52 09-02-2016, 06:22 AM

Last news, and good news.
Experiments included to try steel phosphor-bronze strings on the crossover, and nylon strings on an acoustic. Well, phosphor-bronze wound strings sound perfectly on the crossover guitar, while nylon strings generate the well known parasite tone on the western guitar.

Then two different D strings were put on the crossover, one D'Addario and one Aquila, the last being thinner than the first. Well the D'Addario sounded very bad, while the Aquila sounded significantly better.

So the problem was focused on the strings.
Nylon strings were not tied to the bridge of the crossover but fixed at the ending holes of the bridge by a knot: the parasite tone was reduced just a bit.

The Aquila strings were obviously chosen to go on with next tries.
But the most significative step was to twist on itself the string, ten-twelve folds, as to tighten the wounding, and while keeping it firmly twisted to fix it to the post and tension to pitch.
Gone. The parasite tone is completely gone on E and D strings and almost completely gone on the A string.
The plain nylon strings were substituted with ball end strings (some D'Addario EJ32) and that's all for now folks.

I have planned next tries with Thomastik "John Pearse Folk" strings, Thomastik "Classic N" and "Classic S" strings.

Rodger Knox · #53 09-02-2016, 01:20 PM

So, it was a ziptone after all.

Me&MyGuitar · #54 09-02-2016, 01:34 PM

More news.
after a warm up of the strings the parasite tone comes back thus confirming that it is a string problem.

Ned Milburn · #55 09-02-2016, 04:49 PM

Quote:

Originally Posted by Me&MyGuitar

Last news, and good news.
Experiments included to try steel phosphor-bronze strings on the crossover, and nylon strings on an acoustic. Well, phosphor-bronze wound strings sound perfectly on the crossover guitar, while nylon strings generate the well known parasite tone on the western guitar.

So, let me get this straight...

Did you really put steel string guitar strings on a "crossover" nylon string guitar??

Do you know that steel strings have double the tension of nylon strings, and you risk doing severe damage to your instrument??

Ned Milburn · #56 09-02-2016, 05:02 PM

Quote:

Originally Posted by Howard Klepper

As I said in my first post, all that has been described so far points to frets that are too low, so that there is not enough downward force on them when fretting to stop the string unless the finger is close to the fret.

With low frets, proper technique becomes even more critical. The "Fretless Wonder" probably had the lowest frets of any commercial mass produced guitar. I've played what I remember to be an original 28 years ago. Much fun!! Fantastic guitar. Owned by a university friend of mine, Patrick. Not so much trouble fretting at all. But I wouldn't want to do much bending on it.

FWIW, I'd be reluctant to suggest from all the posts so far by the OP that the frets are too low. Even if they are .6 to .7mm tall, there shouldn't be too much trouble with left hand fretting - WITH proper technique!! I doubt the frets are lower than .6mm. Fretless Wonder was near .5 or .4mm as I remember (never measured, but am PDG at estimation.)

Still, I agree with Will Kirk that a video of the good and offending notes showing left hand technique at the time would be important to positively determine that technique is a big factor, or to positively eliminate the possibility of technique as a factor.

Anyhow, this thread provides juicy nuggets for enjoyment... It's all good!! ;-)

Me&MyGuitar · #57 09-02-2016, 05:39 PM

Quote:

Originally Posted by Ned Milburn

So, let me get this straight...

Did you really put steel string guitar strings on a "crossover" nylon string guitar??

Do you know that steel strings have double the tension of nylon strings, and you risk doing severe damage to your instrument??

Sure i know, was not me but the luthier doing it and of course only the D string was tested

Ned Milburn · #58 09-02-2016, 06:32 PM

Quote:

Originally Posted by Me&MyGuitar

Sure i know, was not me but the luthier doing it and of course only the D string was tested

Aha!! I see. Good good!! I missed the post above mentioning that it was just the D. ;-)

funkymonk#9 · #59 09-02-2016, 08:28 PM

In the name of science and mysticism, i am really hoping we get a video demonstration of this demonic parasitic tone.

Food for thought, if we play it backwards , it might tell us what it wants??

On a serious note, so no buzzing from these finicky strings when played open or with harmonics?

KellyTurci · #60 09-05-2016, 08:50 AM

Hi..i am a new user here. As per my knowledge when you pluck a string it is normally moving at some angle to the top; neither perfectly 'horizontal' nor perfectly 'vertical'. There is thus some string motion, and force, on the end points at the fret and saddle top in both directions. The horizontal string force can cause it to roll across the fret top a bit. If the string rolls at either end it is, in effect, a little bit longer in the 'horizontal' vibration than it is in the 'vertical' one, and thus it makes two notes at the same time with slightly different pitches.

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