Hi Ron, OK, thanks for the explanation (and the photo)! > Hi Sarah, > This is done where there should be a cutoff bar, but isn't, like the > Steinway B shown here [link redacted at request of site owner - Jul 25, 2015] > I understand it, when the soundboard gets too big (as they most all are), > and the ribs too long, the board breaks up into too many competing > vibrational modes and resonances and fights itself. The small bar > connecting rib bottoms stiffens critical areas and helps minimize the > formation of these counterproductive modes. It also stifles some necessary > soundboard movement, so the ribs are thinned where the bar attaches to try > to get back some, but not all of what the bar eliminated. It's a fix of the > fix. The second step level is the regular feathering. Putting in a real > cutoff bar instead would have been a better approach, but would have > lowered the number of square inches of active soundboard area, which > wouldn't have looked good in the brochure. I don't know why they did it in > the tail too. Hmmmm... I doubt it was for reasons of boasting more square inches. I actually have one of the old Wissner catalogs (from 1914, I think), and there's very little in the way of specs (Style H / Wissner Concert Grand / The concert pianist's choice / length 8 feet 11 inches', width 5 feet / Made in ebony, mahogany, and oak" . Of course most things back then were sold with quite a paucity of specifications. Were cutoff bars consistent with the technology of the day (1933)? > >Was it a way of bracing the crown, which is quite a lovely one. > > Measured where? As I recall, roughly the tail-most 2/3 of the soundboard, measured parallel to the ribs. I didn't really have adequate access to the remainder of the soundboard to stretch a line. It has about a 1/4" crown in these areas. Peace, Sarah
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