Whatever vibrations the rim does not immediately reflect should be quickly carried around the board's perimeter and transferred back to it. For this reason, a very dense rim/case of very hard materials should be used, as it transmits vibrations the quickest. And this is, I believe, one reason why old American pianos sound so gorgeous: the rims and cases were built of ash or maple, old growth with very close rings, properly seasoned and very hard. Particularly Victorian era pianos. So a stiff rim helps the crown stay up and refects vibrations back to the board, and a dense rim carries intruding vibrations around the piano and back into the board where they might do the most good. I have no compunction about neatly placing bolts/screws between framing members and case parts to facilitate this stiffness and transmittance, as metal transmits vibrations better than wood and will not resonate if embedded in it. Results bear this out. Gordon Stelter --- Richard Brekne <Richard.Brekne@grieg.uib.no> wrote: > We keep ridiculing this, without really knowing what > it refers too. Similiar subjects come up and get > discounted more or less out of hand also. Yet much > is made of the importance of string > / soundboard impedance match to sustain and power. > Perhaps there are other "impedance matches" to the > strings energy that play an important / significant > roll in the "end product" sound of > the piano. Perhaps its not so much a matter of > whether one rim reflects more or better then > another... but rather that one rim relfects an > optimal amount.. ?? > > RicB > > Farrell wrote: > > > This is what I am describing on the S&S upright. > And are you speaking in reference to the "magic > circle of sound"? Does a laminated rim "reflect" > sound better than a solid timber frame? > > > > Terry Farrell > > > > - > > -- > Richard Brekne > RPT, N.P.T.F. > UiB, Bergen, Norway > mailto:rbrekne@broadpark.no > http://home.broadpark.no/~rbrekne/ricmain.html > > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives __________________________________________________ Do you Yahoo!? Yahoo! News - Today's headlines http://news.yahoo.com
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