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I just put the top and bottom string on an 8 string acoustic I am building and immediately noticed a buzz with the low string. Note that this low string is pretty fat, .080 and has a core, and two layers of windings. Here is my troubleshooting:
-took the nut out of the equation by pressing different frets, no change
-held the string with tension, connected only at the bridge, still get a buzz
-removed string, tapped the body no buzz
-removed the string, left on the metal bridge parts (this is an unusual bridge with tuners), tapped the body, no buzzing

Two complicating factors are
1) I must remove the windings at the end of the string to work with my bridge
2) The end of the string is wound around a post so this is a little mass of wire
I believe I have eliminated both of these in my testing.

Has anyone ever seen the windings of a string cause a rattle ?

Thanks.

Is this one of those headless guitar?

If you press down on the last fret and still get buzzing, then it's the bridge, string, or anything else NOT related to action or frets. Sometimes it could be the pickup if it's set too high. It can be a bad string as well, some poorly made or defective strings have loose windings that causes buzzing.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Yes, multiple times. After all, we are talking about a few cents worth of steel.... it can easily be the culprit.

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"Act your age, not your shoe size" - Prince

Yes. Headless acoustics - a bad idea I refuse to give up on. Kinda like marriage.

8 string eh?

With electrics tuned to C.... which is popular these days with shredders they often have buzz issues because there is not enough tension on the low strings AND the fret work is either not true and/or the action is too low for the condition of the fret plane. The only way to know.... if your fret plane is clean is to test every fret to be sure that they are not loose AND use a precision ground leveling beam and marker to do a proper fret dress. Any attempt at addressing any region of the fret plane or individual frets will not reveal the condition of the fret plane - it has to be addressed as a whole.

With acoustics even one half a step down from conventional tunings can cause buzz issues again for the very same reasons the fret work is not perfect and/or the action is too low, improper relief, etc.

Also if there is a kick-up or ski ramp at the body joint (is it a bolt on Fender style neck, bolt on acoustic style neck, etc....) a low tension string, imperfect fret work, action too low for this instrument are also possibilities.

Pups, if this has em can be especially a contributor as mentioned when tension is low AND the strings are too close.

Metal bridge, modifying a string with multiple windings etc. are all suspect as well.

Since you mentioned it and we have no way to see what you have here you said that you only put two strings on the thing so far - is the relief proper, the neck could be flat, not enough relief, or in back bow as well.

There are a host of possibilities including a very real possibility that there are multiple issues as well here and a picture of the instrument, bridge, etc. would be helpful?

Regarding bad strings sure, happens all the time.... Some brands suck for inconstant windings including some very beloved brands.... Since you modified the string that would be my first suspicion in respect to strings though.

Trying to recreate a rattle or buzz with no strings and simply tapping around is not a definitive method that can eliminate this possibility either because vibrations are often "sympathetic" meaning that they are excited at certain frequencies and only these certain frequencies. Our tapping around won't recreate these specific frequencies.

A pic would really help including close ups of both termination points of the "speaking length" of the strings, the bridge AND measurements of the current action measured at the 12th in 64th inches would also help. A measurement of the relief, pup distance to string bottom would also be on my list to explore.

Right now though I can think of over 30 possibilities so it's time to start eliminating them.

Since you just posted too as I was writing this a pic of the neck where the headstock would be with close-ups of the string termination method/points is also valuable.

PS: A couple of years ago we repaired a Martin that had been shot with OO buck, that guy likely did give up on marriage.....

One more baseline comment.... With bass guitars with say a .100 string low action is considered 7/64th" at the 12th. If your .080 is any closer than say > 6/64th" at the 12th you are pushing the possibilities.

First things first, did you fret the last fret and see if buzzing still persist? If so it has nothing to do with action or frets.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Thanks for all the suggestions on my Martin D-28 copy. I should have pointed out that the neck was on a previous guitar and working fine. It was made of hard rock maple with two CF spars down the middle so it doesn't move much.

Also I removed the neck, and with the string still attached to the bridge, held the string with tension and still heard the noise.

I was gonna wait until it was prettied up to post pics, but here it is, still with a few warts and the tuner cover off.
I built this as kind of a learning experience (first time with gramil and binding yay !) and made several screwups, but none fatal.
Between making the neck and making the new body I had one year of luthier lessons, and three years of practice, and it shows, I think.
I know the level some of you are at, so it is a little embarrassing to have you seeing my disturbing creations.

Sometimes the string can buzz on the bridge saddle (or whatever the equivalent is on your baby). The cure is usually to make the break angle steeper and the crown of the saddle very narrow.

I have classicals that will buzz faintly on the open base string if I release the tension, e.g., remove all the strings at once and then restring. After several days, the buzzing subsides. I am assuming there is some part of the guitar that gets "floppy" if it is not kept under tension.

Very original and cool!
I dig it!

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wah
Wah-wah-wah-wah
Wah

The last pic looks like my broken head stock Les Paul, before I fixed it!
Lots going on there. Looking forward to the finish line!

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

I see some electrics that have a string retainer clip just behind the nut on the bass side. I presume because it is not practical to get the tuning keys close enough to the nut to keep the strings from bouncing up and down on the nut. Maybe you need one of those clips behind your bridge saddle.

Lac thanks for the pics! Also nothing to be ashamed of here the guitar is very cool and I can now see the vibe that you are shooting for.

I can also see what may very likely be at least one or two of the issues if not the primary issue.

The break angles both over the nut and the saddle are both highly suspect to me.

First looking at the nut slots and the fact that this headless wonder has no set-back angle on the headless part the strings when transversing the nut slots have very little break angle....

What happens when this is the case is the vibrating wave of the strings can vibrate past the nut face up into the slot. This makes the "speaking length" of the strings continuously variable... and impossible to play in tune.

The issue is more profound, the lack of a break angle, with heavier strings because these strings have more gentle arks over the nut face and the saddle. Hence you are noticing the buzz for now on only the low string. I suspect that it will be present on the next lower string too.

The same issue appears with the saddle and the tail section, very little break angle making the vibrating wave also very possibly transversing the saddle and again altering the speaking length of the string.

Solution: Increase break angles for both the nut and the saddle and this will require a bit of creative thinking on your part or possibly reengineering the original design. There is a reason why arch top instruments have taller saddles than conventional acoustics and this is because with the use of a tail piece there is limited break angle. Make the saddle taller, over set the neck angle and the break angle gets increased.

The nut slots also look like they are cut too shallow for my liking as well which also can result in the vibrating wave transversing the nut face into the slot. And again the thicker the string the more likely it is to do this.

One more thing, can't see the bridge very well but is the saddle rock-solid steady in the saddle slot? If the saddle can rock AND if the break angles are anemic there is very little downward pressure on the saddle which would feed into how firmly mounted the saddle is.

Cool design but it looks clearly to me as if there are some break angle issues at perhaps both ends of the speaking length of the strings. You could simulate this on a bench stringing up a 2 X 4 with the same strings, same scale length and then duplicating the break angles that you have now and then increasing these angles to see what you get.

Lastly a general guide to nut slot angles thanks to Frank Ford is half the set-back angle of the head stock on a conventional acoustic instrument. This is usually around 7 - 8 degrees. If you measure your break angles you will see that they are not even close. More shallow angles work to to a point.... but it looks like you may have pushed past that.

Wanted to also mention as well that I have suspected multiple issues from my initial impressions in this thread. Don't be surprised that as you uncover and address one issue that there may be a few more as mentioned previously.

I'm still concerned since this is an 8 string that the amount of string tension and the proximity to the frets on the low strings may be an issue as well as you sort out the break angles.

Very low tunings on acoustic guitars are very problematic and the nature of the beast can make it even more problematic. Less volume than desired so the player plays harder, etc. further exaggerating the problem with low tunings. And again any issues with fret work, ski ramps at the body, etc. also get exaggerated with low tunings and thick strings.

You might want to do simulations as suggested and work out all the bugs on a bench before applying it to your cool guitar.

Even after years of production both Gibson and Fender were still correcting design issues that were causing buzzing and "strange" noise issues on their most popular guitars. The most problematic features I believe were the metal to metal areas of contact, strings and hardware. I see many of those situations on your design. Even the wing nut on the socket head screw thread size, if too course could be allowing a bit of movement -- which could = buzz. Lots to look at so be patient.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Hesh, thanks for the detailed information, I know you have a ton of experience.

I think I eliminated break angle issues when I connected the string only to the wing nut and held it up with tension using pliers and still heard the noise, with no nut or bridge involved. FWIW those are tests nuts and saddles. I planned to mount a string retainer an inch two behind the bridge to guarantee break angle. I am trying to determine if I need it or not. I do this by listening to the string, then pressing down hard on the string behind the bridge to make a steep break angle, and listening for the difference. I will probably go ahead and make one, since that will allow me to use a normal saddle instead of cutting little slot in it to align the strings.

You are spot on about no set back angle on the nut, I guess I just got lucky as I have been using this neck for a while on another guitar and haven't noticed any problem. I do make sure to cut the nut slot ramping up toward the fretboard. I will consider this if I make another headless neck. Us jazz players frown on playing open strings anyways.

The test saddle does sit in the test bridge tightly, but I will be making new ones shortly.

I am now 90% sure that in pulling off the two layers of windings I may have comprised the string. I say this because 1) I still get a buzz holding the string with plyers, connected only to the tuner, and 2) the next string up, tuned down to the F# makes no noise at all. I have one more .080 left and I will try it after getting things adjusted. I have been ripping off windings for years and this is the first possible problem I have encountered.

You are correct, I am seeing some normal issues arise as I have tuned it up to pitch with all eight strings. It appears I have invented the adjustable neck without realizing it. If I want to change the neck angle I merely tune it up to pitch. The fingerboard at the nut rises about 4mm when I tune it up. I am now adjusting the neck angle to be 4mm too low and see if I can dial in a stable low action. If the body is not strong enough (I didn't show the two large access panels in the back which may weaken things) then I might just have to start over. I am out in left field with these designs, so a lot can go wrong.

One of the design goals for the original guitar was that it fit in a 22 inch suitcase for air travel (after unbolting the neck). This meant scale lengths of 25 and 23.5 Getting a low F# out of a 25 inch string requires the .080 which has seemed to work but doesn't really sound good. I will say that the high strings sound noticeably different / better at 23.5 inches. I have had to use a higher action on the bass side but I have made it work.

The body end of the fretboard does have a little wood and CF under it to help keep things straight.

Thanks for taking the time to point out issues.

wbergman: Maybe I should use some kind of clip on the headstock since the low F# tries to wander out of the nut slot.

What does a 25" 8 string sound like ? Here is the neck and previous body before it imploded.

[youtube]https://www.youtube.com/watch?v=6pf9CmFqEbU[/youtube]

Thanks for posting. I've never seen an acoustic like yours. Hope everything works out and you can give us an update.

Pete

If the string buzzes on all (or most) notes, and the buzz goes away if you tune it up or down a semitone, it could be that the 'zip tone' longitudinal wave is too close to a partial of the string. Another way to check it is to pluck the string right over the 12th fret, which won't activate the 'zip' tone, and should make the buzz go away if that's the problem. This is NOT a common issue, but it can happen. Sometimes you can get it to stop by simply using another string; the 'zip' tone varies depending on the construction, and double-wound strings can be particularly inconsistent.

Experiments that I've done indicate that six degrees of break angle can be 'enough', although a bit more is desirable. A taller bridge could help achieve that, with, of course, the proper neck set.

Mystery solved, it was the string. I bought an Ernie Ball .085, pulled the winding off the top 6 inches, installed it, and no buzz.
I have always used Ernie Ball, but JustStrings was out of the .080s so I bought the D'addario .080.
Either the D'addario was defective or it could not tolerate my de-winding process.
I have had no problems with the Ernie Balls, doing this for a few years now.
Thanks for the suggestions.
Will post a pic or video in a few weeks when it is finished.