Hi Terry, > I don't know how the numbers would actually work out in > a working soundboard, but perhaps its not inconceivable that a CC board > could end up with similar stiffness as a RC&S board - by varying panel > thickness or whatever - maybe it's just that stiffness is achieved in part > by different means (and that may only be a small percentage of total > stiffness). > > If what I am suggesting holds any water at all, it may be then that the > two > systems might not necessarily produce greatly divergent tonal qualities. I'm just speculating, like the rest of y'all, but... I don't think total stiffness is the whole story. With a CC board, the stiffness is a function of cross-grain compression, and the elasticity is with respect to a directionality of compression for which the tree (that grew the wood) was ill equipped -- a crushing force from the side. The tension, on the other hand (and there must be tension to oppose the compression) is in the ribs and runs longitudinally with the grain (the way the tree was built to handle it). There is also some tension/compression in the rim, in the direction of the grain. In all this mess, there is a mix of very elastic elements (longitudinally tensioned/compressed fibers) and less elastic elements (transversely compressed fibers). Those less elastic elements are going to "modify" vibrations in the entire structure by "soaking up" (or more accurately dissipating) vibrational energy. How will the vibrations be "modified?" I don't know exactly. My guess is that there is hysteresis that would dissipate higher frequencies much faster than lower frequencies, resulting in a "mellowing" of the tone. In a RC/S board, tension/compression runs completely in the direction the Great Goddess intended -- longitudinally. Trees were designed to be very sturdy and elastic in that direction. Vibration will not be damped so much by hysteresis in the system, although there will still be *some* hysteresis. I would think a RC/S board, therefore, would tend to be more "brilliant" or "bright." Of course there's another very important factor in all this mix: voicing. Side by side, CC and RC/S pianos are going to be voiced by the same technician to have the same tonal outcome in mind. I suspect a CC piano's hammers are going to be inherently brighter than a RC/S piano's in order to achieve a similar tone. However, I also suspect the upper partials on a note played on a RC/S piano will sustain longer, retaining more of the the "brightness" of the sound throughout the note's duration. So while the sound may be similar on attack, it may differ on sustain. The difference may be very subtle. Perhaps all things being equal, the sustain in the high treble of a RC/S piano will also be inherently longer, due to less hysteresis in the system. If all this is true, a CC and RC/S piano may have somewhat different flavors in performance. A CC piano may feel/sound slightly brighter during faster passages and darker during slower passages, with melody delineated more clearly from accompaniment. A RC/S piano might be more uniform and overall better suited for more "brilliant" works (acoustically brilliant, that is). Of course this is all just arm chair speculation on my part. Does any of this jibe with what y'all have experienced in the field? Personally, I'm a big fan of the expressiveness of the American Golden Age pianos, and perhaps some of the expressiveness in these pianos derives from the inefficiencies of the CC board. On the other hand, it's hard to argue against the longevity, stability, and treble response properties of an RC/S board. It's equally hard to argue against the smooth, brooding qualities of one of Ron Overs' beautiful pianos! It would be very interesting if someone were to experiment with a hybrid board, combining the properties of CC and RC/S. (Would that even be possible? Perhaps RC/S in the treble end and CC elsewhere? Perhaps a split board, joined at the rib???) Or how about a different sort of board entirely? How about a violin-like board that has its crown milled/sculpted into the wood like a very shallow bowl, lightly supported/stabilized with smaller, shaped ribs? How about a RC/S board with an electromagnetic low-pass damping device that would slowly dissipate higher partials? So many fun possibilities! Fascinating stuff! :-) Peace, Sarah
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