>Does this mean that you modify the bracing on >your pianos? Many pianos seem to have no bracing >along the straight side. And many seem to have >all belly rail support concentrated in one spot, >and in a spot that I might think it's not so >important that it be stiff. Yes. The bass cutoff bar adds bracing to the long side, and another cross brace can be added too if I think it needs it. There is usually a considerable span of un braced belly rail through the mid treble. Since part of the idea in doing these redesigns is to fix the many killer octave associated problems, I put one there too. I use maple for the cutoff bar, but usually a softer wood for the bracing. >Actually I was thinking more of a theoretical rim >which is not massive at all but is more like a piece >of sheet metal bent around in the shape of the >board perimeter. >It would be so light and flexible that it couldn't >absorb any energy. The opposite of the conventional >thinking which is make it massive and stiff so it >won't absorb energy. Well, how about make it so >light and so flexible that it can't absorb energy? > >Phil F It wouldn't terminate the soundboard perimeter then either, and I would think it would quickly use up the available soundboard energy in flailing about, even though the plate mounting would probably necessarily add some stiffness. That's why I said I thought rim mass and stiffness was about control. The more interacting variables there are in a dynamic system, the less predictable and controllable is the product. Ron N
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