Hi Ron! Once again, I am not talking about rebuilding, I am talking about new boards. You say: > Define "properly". Soundboards are typically crowned to provide more > stiffness for the given mass. They become stiffer as the crown is > depressed. That stiffness and spring resistance against the spring > downbearing load of the string plane provides the impedance match for what > we occasionally consider to be good tone in a conventionally built piano. A rib-crowned board, if I understand things right, should be not that much different in terms of stiffness from a flat board with flat ribs that ave the same strength. A crowned rib is not working like an arch in architecture - it works like a beam supporting a vertical load, at least that seems to be what people say around here. So wether you make it crowned or not, this should be relatively unimportant. > Everyone has heard of these pianos. Most of them are owned by the guy who > bought the new Corvette for $100 because someone died in it. How many have > you actually heard for yourself, and what was the condition of the other > dozens, if not hundreds of factors involved in this assessment? Let's forget them. > > > >So, why is a crown necessary? > > To provide the necessary stiffness under load - if it was designed that way > in the first place as most of them were. But can't that stiffness be provided by a perfectly straight (flat) set of ribs and a flat board? Calin Tantareanu ---------------------------------------------------- http://calintantareanu.tripod.com ----------------------------------------------------
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