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Due to friction at the v-bar, there is a range of Non-Speaking Length (NSL) tensions that result in no string slippage at the v-bar.

(NSL tension is the tension of the piano string on the tuning pin side of the v-bar)

This range narrows and rises on hard blows.

The NSL tension must be left within, and must remain within, this narrower, higher range, or stability won't occur.

I call that range of tensions, the Tension Band.

What is the standard terminology that all piano technicians use when discussing this concept?

I am NOT looking for a definition that you think would be good. I am looking for a CURRENT definition that is used in standard schools and texts.

Please refer to an actual text book or article if possible.

Thank you for your help in this matter.

I don't know of any. If there is not one that is generally used, I guess that means one is not needed.

Oh, wait! I remember reading a reprint of a PTG article in the book "Different Strokes" by Ken Burton. It was about the "Marshmallow Zone." That term has been used on this Forum, also. If I remember right, it describes a range of position of the tuning pin rather than a range of NSL tensions. I think this is a more practical way to approach the subject because, after all, that is the way the tensions are controlled - by the position of the pin.

Still, it is not a term often used. It is not really needed, I suppose.

Logically (and as my mentor, who tunes regularly for commercial recording sessions and concerts will attest), just use a hard test blow or two. If the pitch doesn't move, it's stable. Full stop.

Yes, technique is a factor in terms of understanding whether I've been pulling or pushing the hammer and if that results in pitch change of the speaking length or not, but that seems like common sense, not something upon which a dissertation must be proffered. If I've moved the hammer counterclockwise significantly and the pitch hasn't changed yet, I'm not just going to leave it there because a hard whack is going to send the pitch flat. It was easy to notice early on in my tuning, because I was able to literally pound flat notes in the capo section at will, and the needed adjustment in technique was pretty logical.

OK, I can see some sense in spelling out just what you mean, Mark, and I hope you can, too. It also sheds light on why some say that "pounding" for stability can result in notes drifting sharp later on. Yes, with hard blows the NSL must be higher for stability, but when you specify that there is a "narrower, higher range" where stability occurs with hard blows, it gives one pause. What happens if the NSL is at a tension at the highest part of this "narrower, higher range" and the piano is played with light, fast blows such as in a soft trill? Is the NSL still at a tension where it will be stable? I would think maybe not, and this is what I suspect happens to some that "pound" for stability and the pitch drifts sharp. Vibration, and not just tension, effects string rendering across bearing points.

I do not believe that Mark, unlike yourself, is defining or discussing a technique.

Ian

Jeff,

I fail to see how your comments answer Mark's question as posted in this thread.

Ian

I admit this last one broadens the Topic a bit. See, now that standard terminology is being used, I suspect there is a problem with the definition that Mark has given. It doesn't seem workable. The first example that comes to mind is if someone said their definition of a "Scroggins Sunset" is when it is sets in the East on a winter day and wants to know if there a recognized, technical term for this used my meteorologists. Well, I hope there wouldn't be and it would be proper for someone to point this out.

Likewise, when I studied and thought about Mark's definition, I saw a problem with it and pointed it out. It may not be what Mark means at all, and yet that is what the words say. See, this has happened before...

New terminology for well known (and old) concepts?

What for?


In Ken Burton's Different Strokes book this subject is fully treated, considering not only the string and all its segments between bearing points, but the flexing and twisting of the pin and the different tuning techniques used to get a stable tuning.






























Bill Bremmer (and many other): tuning contiguous major thirds, including F4A4

Mark Cerisano: Lower skeleton, Upper skeleton

same concepts, same procedures, except Bremmer's instructions are clearer.


Rick Buttler: stretching the tuning, M3<=M10<=M17=M6

Cerisano: P4 window

same concepts, same amount of stretch, clearer in Buttler's book.


Many piano tuners: cracking unisons, shimming, tuning open unisons.

Cerisano: DSU technique (double string unison technique)

same concepts, same procedures, different words...


He talks about well known concepts and procedures used by well reputed piano technicians but he invents and uses new terms. One can think he has created a new technique or he has discovered new facts if one doesn't know it already exists and was developed by someone else. It seems to me that the only goal of using this "new" terminology is to make the name of Mark Cerisano shine...

It seems to me that since we are so used to saying that the tension should be EQUAL throughout the string length, that there is some confusion over Mark's proposal that the upper NSL should in fact NOT be equal, but rather slightly higher, and that brings about superior stability.

Amy I correct in asserting this?

Pwg

This is a non-answer to the question in the OP, but is perhaps suggestive that no such term exists as that which the OP seeks. From Reblitz page 45:


Mario Igrec in Pianos Inside Out on p115 says, under "Tune and set the string" describes a process of using the lever, and striking firmly - "pound the key twice in rapid succession", "the two strikes equalize tensions in different segments of the string".
Daniel Levitan in The Craft of Piano Tuning has a more complex discussion on pp180-182, but no term is given that would meet the criteria of the OP.

Rafael, you may be right, but it will do no good to point it out.

My method has been developed from the premise that hard blows are not needed nor wanted, for different reasons.

Also, the idea that all segments must have equal tension contributes to complicating the situation more than it needs to be. Friction at the bearing points allows for different tensions across them.

Nice research about the different technicians who have similar definitions and methods for the same concepts I talk about. However, I have a slightly different take on all of them.

Example Unison Shimming is generally meant to be a way to fine tune a note after the tuning has been done. I tune the whole piano with Unison Shimming, and I use that term often to describe what I do.

I.e. DSU = Tuning the whole piano with unison shimming or cracking.

I find it interesting that there are at least two people on this forum who truly believe there is nothing more to add to the lexicon of piano tuning. Is that really true?

This is not my idea. I got it from other more experienced and skilled technicians. I just took on the task of trying to explain why.

Asserting what? That there is some confusion, or that Mark proposes that the NSL tension should be higher, or that it brings superior stability? No matter.

I do think about these things, not just looking for fodder but for substance. There are ways to tell if a string is stable, but can we ever be sure if the NSL tension is higher, lower, or equal to the speaking length tension? Maybe with extremely low friction, but otherwise, I am not so sure. Fwiw, I try to have the NSL higher in tension as I think that is best.

Yes, there are ways to be certain. Simple analysis.

(Trying to post a reply again. First seems vanished in cyberspace. Apologies if others can see it and I can't.)

Brian Capleton in his Theory and Practice of Piano Tuning uses the term "hysteresis width" to mean something like what you are talking about, Mark. Other interesting terms he brings to that discussion are "coaxing", "nudging", and "pin recoil".

At the level of questions you are asking, I'd suggest you get the book...

The more I think about it, the more I doubt it.

First, I have never heard of anyone actually measuring the tension of an NSL and I think it would be a very iffy thing to try. Remember there is a very short piece of NSL and then a longer one. That means two bends. There must be variable friction as the bends slide on the bearing surfaces. I think about the times I dealt with wire rope on ships and how just a bit of a bend around bearing points can make a huge difference in the amount of strain that can be maintained with much less effort. And kinks sure can behave strangely.

Anyhoo, how we assume the tension of the NSLs to be works as a model, so it may be a moot point.

This struck me as being a non-answer, as well. If it is so simple, you should be able to explain it.

I'll give you one example.

First the background.

NSL tension sensitivity depends on two things: the length of the NSL and the tightness of the pin block.

The longer the NSL, the less sensitive the tension is to pin movement.

The tighter the pin block, the more the pin moves, and the more the NSL tension changes during tuning and after the hammer force is removed.

Let's consider raising pitch with slow pull, on a large grand with not so tight pins, hammer at 12:00.

When raising pitch the NSL tension is at the top of the Tension Band. WE KNOW that.

When we arrive at the target pitch and remove the hammer force, the pin unbends to the left, perpendicular to the string; no change in NSL tension.

The pin untwists counter-clockwise. This lowers NSL tension. But because the pin block is not so tight, and the NSL tension is long, we KNOW the NSL tension does not lower very much at all.

This is a rare situation where the pitch may actually rise on hard blows because the NSL tension is left so high in the Tension Band.

I have proven these hypotheses and you can too. Just slow pull a string to any pitch, take note of the pin tightness and NSL length, measure the pitch, do a test blow, measure again.

If you change the hammer angle, you should be able to predict the resulting change in stability.

I.e. in the example above, if the pitch does rise, a change in angle from 12:00 to 3:00 will add unbending toward the string when the hammer force is removed. This leaves the NSL tension lower in the Tension Band, which may be enough to stop the pitch from rising.