Hi Again Allen: I have observed negative inharmonicity in pianos, but never on F3. If I ever should, I would do this: Pluck the F3 string between the strike point and V-bar at both F5 and F6. The normal strike point of the hammer does sometimes interfere with the display of the 8th partial - somewhat similar to the kind of display we get when tuning a wild string which has two frequencies going at the same time. If this still shows negative Inh., then measure F#3 or E3 as tho' it were F3 (assuming it to be the same kind of string, ie wrapped or plain). The rationale for this is that you wouldn't want one odd-ball string to control the tuning of so many others. In this particular case (Knabe Console) the F3 is probably a wrapped string. Normally if a wrapped string has extremely long unwrapped portions in the speaking length of the string, this will make the inharmonicity higher. The only thing I can think of which would make the inharmonicity lower would if be if there is added weight in some spot on the string. I have observed glue spots on strings (sloppy gluing of the dampers) which can play havoc with inharmonicity. Some European and Japanese pianos have had the end of the copper over-wrap itself about 1 inch to give better security, but it also plays havoc with the inharmonicity (usually in lowering some of the lower partials. Jim Coleman, Sr. On Fri, 24 Jan 1997 Gilreath@aol.com wrote: > In a message dated 97-01-23 16:35:52 EST, you write: > > << The string in question may very well have negative inharmoncity for some > partials, but it is not clear from your description that this is what you > have. > When you say that you find F6 to be a little flat, do you mean F6 as the > 8th partial of F3? or F6 as the 2nd partial of F5? And flat compared to > what? > > -Bob Scott >> > > Sorry for any ambiguity in my original post. When playing F3, tuned to F5 > then measuring F6, still playing F3, I had to set the Accu-tuner to -1.6. > Hence, an obviously unusable, negative unharmonicity reading. Also, thanks > Ted for the Journal reference, I'll look it up first thing in the morning. > And thanks to Jim for the response, but I was in Tune mode, so this should > have been a true reading. I heard about the phenomenon but had never > observed it. > > Allan > > Allan L. Gilreath, RPT > Gilreath Piano & Organ Co. > Berry College > Gilreath@aol.com
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