Abnormal string vibration

[killemall8]

So you all know ive built a large amount of guitars. Somewhere in the neighborhood of 250.

Ive only had this issue on maybe 2 or 3 of them ever.
But i have one that i made last  year that i still have, that has this issue to an extreme that ive never experienced.
Its a 25" scale explorer.
With the action a little higher than what i normally set, and the nut height perfectly, when i pick any string (bass string are MUCH more noticeable) There is so much circular vibration that the string is vibrating in almost 1/8" of an in circles, causing huge fret buzz, because its hitting almost every fret as it vibrates. The low E is so bad it looks like its a physical representation of an audio wave or something.
Even with 52 gauge strings it still does it.
Any ideas?

[Bizman62]

3 hours ago, killemall8 said:

The low E is so bad it looks like its a physical representation of an audio wave or something.

For what I've recently learned that's exactly how strings move but it's weird that you can see it. Have you by chance had an eye surgery and by accident got a bionic ultra high speed camera for an eye? Sort of a Six Million Dollar Man, eh?

 

[killemall8]

1 hour ago, norm barrows said:

i might try smaller gauge strings.   i run a 38 low E for example - a far cry from a 52.

while heavier gauge might require more tension for the same note, it does tend to flop around more.

but don't take my word for it. i went as light as i could go 40 years ago, and never looked back.

tonal effects of heavy stings (like most tonal effects) can be gotten by other means that don't reduce playability. 

I tried a  normal 46 and it was worse, which is why i tried a heavier gauge to see if more tension helped.

[killemall8]

1 minute ago, Bizman62 said:

For what I've recently learned that's exactly how strings move but it's weird that you can see it. Have you by chance had an eye surgery and by accident got a bionic ultra high speed camera for an eye? Sort of a Six Million Dollar Man, eh?

 

Haha, its not hard to see when its basically flopping around

 

[curtisa]

4 hours ago, killemall8 said:

So you all know ive built a large amount of guitars. Somewhere in the neighborhood of 250.

Ive only had this issue on maybe 2 or 3 of them ever.
But i have one that i made last  year that i still have, that has this issue to an extreme that ive never experienced.
Its a 25" scale explorer.
With the action a little higher than what i normally set, and the nut height perfectly, when i pick any string (bass string are MUCH more noticeable) There is so much circular vibration that the string is vibrating in almost 1/8" of an in circles, causing huge fret buzz, because its hitting almost every fret as it vibrates. The low E is so bad it looks like its a physical representation of an audio wave or something.
Even with 52 gauge strings it still does it.
Any ideas?

IIRC you asked a similar query a couple of years back about this issue. I don't recall if there were any good ideas that came out of that discussion.

I have built two guitars that exhibited the same issue you have noticed - the lower wound strings would buzz very easily even with excessively high action or exaggerated neck relief. The neck itself had no issues with fret levelling or warps, yet the buzz persisted. The only way to tame it was to change my playing style to deliberately use a softer picking action, which was not really an acceptable solution.

I would say, however, that in both those guitars the bass strings behind each of the saddles was kinked over quite severely as it passed over the crown of the saddle. In both cases this was unavoidable and a quirk of their design. I do wonder if the thicker wound strings vibrate differently if the amount of downward force at the saddle is extreme or the amount of stress placed on the string near the point at which they bend over the crown of the saddle is steeper.

The first guitar I found this issue was on the low F# of an 8-string (.74 over 26.5" scale length) with a standard Hipshot hardtail bridge. By necessity the intonation of the lowest saddle had to be wound back pretty much as far as it could go, which made the string pass through a right angle bend over a very short distance as it went over the crown of the saddle and through the body. The second guitar that exhibited this issue, the saddles used were the Technology For Musicians headless tuners for multiscale guitars which are quite tall units, and again the string (a low B, a .59 over 26.5" scale length on a 7-stringer) had to make a very sharp bend over the crown on its way to the tuner. There was also some neck angle built into the guitar to account for the high saddles, which would have increased the break angle on the low B string on the saddle even further.

Maybe you could experiment with the bridges a bit? If you have used a Tune-o-matic style bridge you could change the amount of downforce/break angle at the saddle by reducing the angle at which the strings pass over (either raise the stop tail higher or place some kind of spacer between the strings and the body if you're used through-body ferrules). If you've used a hardtail bridge, maybe try installing a normal D string in the low-E position, and tune and intonate it accordingly. Doing so would move the saddle closer to the nut, consequently reducing the break angle behind the saddle (not really a solution, but might go some way to proving/disproving the saddle string angle theory).

[curtisa]

Which is why I didn't mention scale length. I was more highlighting the commonality between the two guitars I built that exhibited the same phenomena as something to explore, that being steep string angle and/or tight bending radii behind the bridge.

[Bizman62]

Just for clarification, does the problem occur on open strings only or also when fretted? And if the latter, does it go away at any point?

[killemall8]

18 hours ago, norm barrows said:

and it [a 53] was better than a 46 ?

start with the basics -   nut slot height above the fret plane, saddle height above the fret plane, scale length.  then move on to string beyond the nut and saddle.    something MUST be different. 

and of course, make sure you have a semi decent fret plane to begin with.

just go down the list, check everything, you'll find it.

and use standard tuning - worry about alternate tunings once you've found and fixed the problem.

once it works with standard tuning, it should be capable of the same alternate tunings of any typical guitar.

 

I have checked all those things multiple times. Re leveled frets, neck is straight. Tried a number of different action heights.
It was definitely a little better with the heavier gauge, but still not playable. the vibration and resonation overpowers the clarity of a fretted note.

Ive only tried it in standard tuning.

[killemall8]

7 hours ago, Bizman62 said:

Just for clarification, does the problem occur on open strings only or also when fretted? And if the latter, does it go away at any point?

It happens on every fret as well.

[killemall8]

17 hours ago, curtisa said:

IIRC you asked a similar query a couple of years back about this issue. I don't recall if there were any good ideas that came out of that discussion.

I have built two guitars that exhibited the same issue you have noticed - the lower wound strings would buzz very easily even with excessively high action or exaggerated neck relief. The neck itself had no issues with fret levelling or warps, yet the buzz persisted. The only way to tame it was to change my playing style to deliberately use a softer picking action, which was not really an acceptable solution.

I would say, however, that in both those guitars the bass strings behind each of the saddles was kinked over quite severely as it passed over the crown of the saddle. In both cases this was unavoidable and a quirk of their design. I do wonder if the thicker wound strings vibrate differently if the amount of downward force at the saddle is extreme or the amount of stress placed on the string near the point at which they bend over the crown of the saddle is steeper.

The first guitar I found this issue was on the low F# of an 8-string (.74 over 26.5" scale length) with a standard Hipshot hardtail bridge. By necessity the intonation of the lowest saddle had to be wound back pretty much as far as it could go, which made the string pass through a right angle bend over a very short distance as it went over the crown of the saddle and through the body. The second guitar that exhibited this issue, the saddles used were the Technology For Musicians headless tuners for multiscale guitars which are quite tall units, and again the string (a low B, a .59 over 26.5" scale length on a 7-stringer) had to make a very sharp bend over the crown on its way to the tuner. There was also some neck angle built into the guitar to account for the high saddles, which would have increased the break angle on the low B string on the saddle even further.

Maybe you could experiment with the bridges a bit? If you have used a Tune-o-matic style bridge you could change the amount of downforce/break angle at the saddle by reducing the angle at which the strings pass over (either raise the stop tail higher or place some kind of spacer between the strings and the body if you're used through-body ferrules). If you've used a hardtail bridge, maybe try installing a normal D string in the low-E position, and tune and intonate it accordingly. Doing so would move the saddle closer to the nut, consequently reducing the break angle behind the saddle (not really a solution, but might go some way to proving/disproving the saddle string angle theory).

I thought about it being the break angle behind the bridge. Its a string through, tune o matic. The distance and break angle behind the bridge is identical to the ones ive made in the past 5 years. I can test it the way you mentioned though to see if for some reason that is the cause of this one.

[Bizman62]

29 minutes ago, killemall8 said:

It happens on every fret as well.

The reason I asked was because I had a thought that for some reason the highest spot on the bridge pieces might not be at the very edge which can cause rattle.

But then I re-read your first post:

23 hours ago, killemall8 said:

There is so much circular vibration that the string is vibrating in almost 1/8" of an in circles, causing huge fret buzz, because its hitting almost every fret as it vibrates.

Which makes me think that the neck may be very bouncy and springy, enhancing the vibration of the strings rather than letting the action slowly die. But how to test that? Obviously tightening the truss rod won't make much difference unless you arch the neck beyond playable. Clamping a rail on the back of the neck might be an option to test if it's a springiness issue.

[killemall8]

4 hours ago, Bizman62 said:

The reason I asked was because I had a thought that for some reason the highest spot on the bridge pieces might not be at the very edge which can cause rattle.

But then I re-read your first post:

Which makes me think that the neck may be very bouncy and springy, enhancing the vibration of the strings rather than letting the action slowly die. But how to test that? Obviously tightening the truss rod won't make much difference unless you arch the neck beyond playable. Clamping a rail on the back of the neck might be an option to test if it's a springiness issue.

I guess that is a possibility, but this is a 5 piece Walnut, purpleheart and maple neck. Should be more than stiff enough to prevent that?

[curtisa]

Of the two guitars I built with the same problem as yours, the neck on 7 had 2x carbon fibre rods plus truss rod and was outlandishly stiff. The 8 had no reinforcement and a single truss rod. I'd be looking at other factors than the compliance of the neck.

[mistermikev]

terribly interesting read.  I know nothing but my first instinct (they might be stinky intincts) was that the guitar just really resonates to the freq range encompassed by the lower strings. 

what if you put tape all over the body to dampen it or clamp another piece of wood to it?  just a shot in the dark.  what type of wood is the body just out of curiosity?  is it light?  (I know you mentioned neck but didn't see body so sorry if you did mention)

perhaps you've created some tesla freq summing death ray guitar! (I'm copy-writing that name!)

[killemall8]

1 hour ago, mistermikev said:

terribly interesting read.  I know nothing but my first instinct (they might be stinky intincts) was that the guitar just really resonates to the freq range encompassed by the lower strings. 

what if you put tape all over the body to dampen it or clamp another piece of wood to it?  just a shot in the dark.  what type of wood is the body just out of curiosity?  is it light?  (I know you mentioned neck but didn't see body so sorry if you did mention)

perhaps you've created some tesla freq summing death ray guitar! (I'm copy-writing that name!)

worth a shot to try those things!
The body is a relatively medium weight piece of african mahogany.

[mistermikev]

58 minutes ago, killemall8 said:

worth a shot to try those things!
The body is a relatively medium weight piece of african mahogany.

was thinking you were going to say something really light. 

once you've ruled out all the things that make sense... just have to start trying things that don't make sense! 

[Bizman62]

6 hours ago, norm barrows said:

we'll all be praying for you that its hardware and not the neck/body.

Amen, Brother!