Hi Jude Jude writes: Still, doesn't an RC&S panel experience similar high compression loads when it's humid out also leading to the accelerated aging. I hear what you're saying about wood, but if we're going to be consistent, why should there be accelerated aging on any type of panel if it's kept in a relatively stabile environment. I'm just trying to get a sense of that interchange of stiffness from compression verse rib support. I guess the hybrid covers the in between range, but I think the variations might be fascinating, soundwise. This basic question is of course at the heart of my querie about calculating how much compression is created when a soundboard must deflect downwards RC&S designed ribs to the degrees necessary. From a general perspective, a soundboard gets subjected to relatively known amounts of down bearing. This is more or less independent of soundboard type. The panel has to take on most of this load in terms of compression. But thats going to vary somewhat depending on how much compression there was at the outset vs how much pressure it takes to deflect the ribs. CC ribs are easier to bend... but one has significant amounts of compression already in the unloaded panel... RC & S panels dont have any real compression in the unloaded state but the ribs themselves are harder to deflect. To some degree these two systems counter act each other in regard to how much end compression there is in the panel. We've heard much about how much compression builds up in the CC and RC boards as it takes on humidity and how destructive it is. But how much compression builds up when downbearing is applied is not more specifically addressed then simply saying it just increases the matter. I asked this same question a couple years back about CC boards and simply got told "I dont know and it doesn't really concern me" by the RC&S camp. In any case... Showing how the three types of boards line up with each other in this regard by describing in quantifiable terms how much compression builds up in each when the piano is strung, up to pitch and at nominal RH levels seems kind of more then appropriate at this point. If someone indeed can do exactly this... its time for a journal article on the matter. Cheers RicB
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