Hi Ron. Nice to read you on this, for sure. My comments in between your text. >> May I precise again : for a certain string with a fixed diameter in a >> piano, when you raise it's tension, you raise it's pitch, lower it's >> inharmonicity, and shorten it's sustain. Agreed ? > > I haven't noticed a drop in sustain, but then I wasn't looking for it. > I'll have to try it and see. Easily and quickly done. Any plain string in a traditionnally scaled piano will stand safely a whole tone up, and maybe up to three tones up. The difference in sustain is already clear with a one tone shift. When you tune the entire > piano as sharp as the string you tested, does the sustain come back? I > suspect it would. Well, I didn't try that, but I don't think it would. I can imagine that the board impedence would change (foreseen that it has crown enough to stand it), but you seem to ignore the string flexibility lowering thing, which in my mind clearly plays against the sustain, and I think in proportions such to overshade the impedence coupling thing. I have noticed that in a freshly > strung piano, treble sustain sounds longer after the third or forth pass > than it does with the first or second chipping. I take that to mean that > there is more harmonic support from the rest of the strings when > everything is in relatively close tune than when most of the strings are > in random counter-phase with the test string. Agreed. But here you have two actors at play : the fact that all strings are close to in harmonic state, which will certainly translate as less impedence from the whole shebam for the one string you measure, and the fact that newish steel has to stretch a bit in order to get the musically desirable properties of less flexibility and more elasitcity. > > >> Do I understand you that your higher trebble strings have higher tension >> than traditionnals, because their length is longer, and that they have >> longer sustain ... but for me, it is the extra mass of the strings that >> is partly responsible of the sustain lengthening, together with the more >> optimal position of the bridge on the soundboard at that place, not the >> extra tension. Agreed ? > > Not agreed. 3mm of extra length doesn't increase mass substantially. It's > also not the optimal positioning of the bridge on the soundboard, because > I can't get the bridge in anywhere near what I think is the optimal > position in the last section. It's the soundboard assembly mass and > stiffness. Ok, I get your point, but then why do you feel it is better to lengthen the upper trebble ? If you expect no improve from the extra mass of the string, nor from the extra length in that they allow for better bridge positionning, then, why longer high trebble ? I can beleive that the impedance coupling is a forefront actor in this, but you would achieve the same soundboard assembly improvements without lengthening the high trebble strings, wouldn't you ? Methink that indeed longer trebble strings improve the tone, sustain, etc. but for the reasons I told. > > >> Intuitively, an ideal string whose breaking strength was infinite, and >> the tension you put on it infinite too, could barely move, if the rules >> of physics still applied continuously the same way as they do in the >> range that we observe. The higher the tension, the lower the flexibility >> (good for inharmonicity, bad for sustain), and the higher the elasticity. >> >> What do you think ? > > I don't do intuitive infinite strength, infinite tension strings. The ones > I work with have built in rules, and aren't isolated from the soundboard > assembly and the rest of the strings. Sustain is mostly a function of the > rigidity and mass (impedance) of the terminations in the wire length, > diameter, and tension ranges present in pianos. Agreed of course. I just wanted to try and isolate the tension parameter, and how it influences the sustain, all other parameters being the same. Uptill now, I stay on my idea that more tension equals less sustain, everything else being unchanged. > > > When you hear a piano, you're hearing what's left after the hammer and > soundboard assembly have filtered and damped what the string is ideally > capable of producing. That is, unless the soundboard is producing some > obnoxious resonances of it's own, which does happen. So it's not just > string tension or inharmonicity that is credited or faulted for the way > the piano sounds, it's how it all works, or doesn't work, together. Agreed, of course. And it has always been my understanding that experiment has precedence upon theory, which comes later and often unneeded. After all, the best scalings I know were done by ear, that is taking in account everything that comes in play, not only those things that we think we understand. > > Ron N Best regards, Stéphane Collin.
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