David Skolnik wrote: > John, > > First of all, I suspect my use of the phrase "unintentionally > misleading" may have seemed too provocative. I didn't mean to imply > that you are mistaken, intentionally or not, nor was it my intention > to personalize my comments, thereby placing the burden of my education > upon you. However, as I reread my previous posts, as well as the > responses, I feel my questions continue to be valid, and remain > unanswered, and that there is a tendency to talk past one other. > > I am NOT a rebuilder. My concerns are both more immediate and, at the > same time, more theoretical. I don't need to know what the board was > doing before stringing, nor do I need to know what it might do if and > when I de-string it. I want to understand how the available > measurements relate to the aural performance of the piano, and I want > to know that these measurements are accurately reflecting the physical > conditions before me. I do believe it is possible to measure this > "distance" bearing, as Isaac Sur Noos called it. Not being a rebuilder should have no bearing on the discussion per se. Tho certainly hands on experience in watching and dealing with the problems and consequences of soundboard construction methods certainly will yield beneficial perspectives, in the end these same qualify you no more to speak authoritivly on the subject matter then if you arrive at the necessary knowledge in some other fashion. My own degree of understanding of these matters still remains at a rather young stage, yet one theme comes back again and again in these discussions. That is that the sound that the panel is able to project is dependent upon its stiffness and mass. Certainly any particular combination of these is in itself independent of string coupling. John Hartman is correct in saying that down bearing can increase the stiffness of the panel without added to the panels mass... tho the strings have mass to... and these things have a habit of working both ways in some sense or another... Still essentially John is correct. The other point that comes into the present discussion seems to be a reference to problems associated with the so called killer octave... or for that matter similar types of panel problems. Perhaps in the loosest sense of the word, these can be seen as weak spots in the panel... where the panels stiffness has broken down for whatever reasons. Localized <<soft spots>> if you will. Its no quantum leap of logic to understand that such conditions that are in direct proximity to string input locations are going to have potential to influence the resulting projected sound greatly, and in what many would deem as a negative manner. None of this has anything directly to do with down bearing, yet at the same time all this is at least in one fashion or another indirectly related. The question remains then can good sound result without any particular amount of down bearing. It seems clear to me at any rate that the answer to this is not more complicated then asking whether a soundboard can be made uniformly stiff enough while being comprised of appropriate levels and placement of mass. If that can be done without the additional stiffness that down bearing supplies in traditional piano design... then so be it. And it would appear, given plenty enough <<oddball >> examples of reverse crown and or buckling that do not adversely affect sound production that this is the case. On the other hand... the lack of any design that satisfactorily would exploit this would tend to counter that conclusion. Just a few thoughts. RicB ........................ > > Is it fair to ask how much negative downbearing you would allow on one > of your pianos? > > Please rest assured, I won't do it on Monday! > > > Regards > > David Skolnik RPT >
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