hello piano lovers. i am sharing with you a curiosity that arose within me when, on several occasions, I found instruments that, instead of dropping, after some time had passed since the last tuning, had risen by a few cents. unfortunately, i did not note the dates of these encounters and cannot say with certainty whether it happened to me more in summer or in winter. it seems to me that it is more with the cold. if that were the case, I would be inclined to imagine the strings shortening due to the effect of contraction, but I also imagine the soundboard stiffening, thereby providing greater resistance to the pressure exerted by the strings on the bridge. which of you has observed this phenomenon and made conjectures regarding it? thanks anyway
It can happen especially in the bass notes. It can also depend on the excessive load of the soundboard, which causes a "climbing of the strings on the bridge." In some cases, this load, which may be excessive, is reduced. In small upright pianos and small grand pianos, the phenomenon can be more frequent due to very little tolerance for excess string gauge relative to their length. The calculation, although precise, is more affected by the balance of tensions, which are never progressive and uniform. Sometimes, even in concert grand pianos, diameters are recalculated—both for plain and wound strings—by increasing them, to further uniform the progression of tensions and/or to enhance the sound. This, however, increases the factor of inharmonicity.
It is not easy to establish these proportions, and since the second half of the 1900s, manufacturers that have entered into competition to satisfy piano listening in increasingly larger "Music venues" have sought to increase the sound more and more, calculating the string gauge and the load on the soundboard "to the limit," sometimes making them almost excessive. Often we end up with an instrument built to "get by" in a large environment and... we cannot "tame" the sound. It always seems too "flamboyant" to us, with great difficulty performing the pianissimo and the "half-tones." We must then avoid "attacking" it by voicing—or rather improperly "softening"—the tips of the hammers, believing we will obtain a sweeter sound. The definitely negative result can be making the hammer rail dull and useless. Instead, it is appropriate to create a second hammer rail on shanks, built with different compressions, that can satisfy us with a more "private," "home-like" sound. The original hammer rail must remain mounted on its shanks and absolutely preserved. Otherwise, the identity of the piano and the references of the original design measurements are at risk.
very interesting. understanding the explanation implies a deep knowledge of complex concepts which, I admit, I have not mastered. I simply let my imagination run wild, aided by knowledge of various materials and their interactions. thank you very much.
