Tailpiece tension?

[santjo24]

Hey guys,

This is actually sort of a guitar question, but I dont trust anyone to answer my instrument questions other than the mandolincafe crew.

I am going to get a guitar and tune it in "new standard tuning" (CGDAEg) so it works like a mandocello and an octave mandolin with a high G string. I cant imagine that the high G string works all that well because of the scale length of the instrument, so I want to cut all the tension I can.

Anyways my question is do tailpieces create higher tension on strings then say a gibson 335 style bridge where the string goes pretty much directly to the bridge and doesnt stretch all the way down to the strap button area. I must admit the physics of strings and tension is kind of a mystery to me, but it seems that if the string is stretched further after the bridge to the tailpiece, there will be more tension.

Thanks guys!

[Rick Turner]

The tension is a function of the scale length, the unit mass of the string, and the pitch. Nothing you do on either side of the nut or bridge changes the tension.

You can probably get a .008" or .009" up to "g" at guitar scale length.

Go onto the D'Addario site for a great chart of scale lengths, pitches, and string tension. You'll be able to figure out the right gauges from their chart.

[Phil Goodson]

But interestingly, in the recent copy of Fretboard Journal, John Monteleone says that he uses a tailpiece which has a longer distance from tailpiece to saddle for the treble strings because he thinks that a longer length causes a "PERCEIVED lower tension" in the strings. Hope I've expressed his theory properly.

[John Arnold]

It's not perceived, it is real. What John M. is referring to is the dynamic tension, which comes into play when you press the string down to the fret, and also felt in the picking hand when plucking the string. That action stretches the string, which also includes the string tension outside the nut and bridge saddle. The stiffness of the top and neck also come into play when considering the dynamic tension.
It is the only explanation of why some instruments feel looser than others, even when the action, scale length, string gauge, and tuning are identical.
Just to be clear, changing the tailpiece length does nothing to alter the static tension...the amount of force the strings are exerting on the instrument when tuned to pitch. The only way to alter that is by changing the tuning or the string gauge (what Rick said).

[Rick Turner]

"Dynamic tension" is a great way to define this as different from "static tension". I hope you won't mind if I start using that term. For a player it's about "deflection effort" because it is in the playing that this string stretch effect is felt. This is about how much pressure is required to move the string a certain distance, and that is elasticity distributed over the entire string length from tuner post to tailpiece...assuming zero friction at the nut. Practically the entire instrument contributes to this "deflection effort" effect...the compliance of the neck including peghead, the stiffness of the top, and I'd say even the stiffness of the back may come into play in how strings feel on a particular instrument. I've discussed this at length with guitar maker Jeff Traugott and it's a very real thing with both acoustic and electric guitars.

[Phil Goodson]

Has anyone actually measured the "deflection effort" with different tailpieces? I would think that this would be fairly easy to do with the right instruments.
And I would think that information might help luthiers design their products to match the requests.

We might start to see longer necks, with the bridges farther from the tailpiece. Talk about straying from tradition!!!

Does decreased "deflection effort" increase the likelihood of strings buzzing on the frets with the same intensity of picking?

[amowry]

There was a thread a while ago where Chris Baird did a test of that sort. He was unable to find any effect of lengthening the string beyond the nut (or bridge) on the force required to defelct the string. I forget when it was, but you could search for it.

However, different tailpieces do affect the force that the bridge exerts on the top, by affect the break angle over the bridge. That can change the overall sound of the instrument, and it might change the "feel" by affecting the ease with which the string slides over the saddle.

[amowry]

Here's the thread with Chris' test: http://www.mandolincafe.com/forum/sh...ht=afterlength

[Phil Goodson]

Thanks Andrew. That was an interesting thread from 2006. Even a little data.

I just tend to be skeptical when everyone "knows" that action A causes result B, when there's no data to be found.

I know that I have "perceived" and deeply believed many things in my life that later on turned out to be totally wrong. And I suspect that I still do.
Perhaps you guys have a dependably better track record than I do.

Good discussion.

[John Arnold]

Good discussion.

I agree.....good analysis all around. But I did notice that the builders were concentrating on mass, rather than stiffness. Both are equally important. When considering the stiffness of the body, you must also realize that the important number is when the strings are up to pitch, which can alter the stiffness of the top in particular.
Tightening the truss rod will also stiffen the neck.

[santjo24]

Thanks guys,

This is why I post my questions on mandolincafe