Hi Terry, I think everyone on this list (who hasn't already) should try to see a high speed film that Don Mannino shows at his presentations. Don, do you make this clip available for downloading? It's a view of the first pulse as it propagates from the hammer to the bridge, then reflects and comes back to the bridge, etc. The film clip stops after a few bounces, which is only a few milliseconds. After a few seconds (not seen in the film), the pulse resolves and you see the typical sine wave that is characteristic of the fundamental frequency with little higher partial content. The string acts as a filter if you wish. When the hammer hits the string, it imparts a broad continuous spectrum of "noise" on to the string (that is the sharp pulse that deforms the string when the hammer hits it). The string has only certain frequencies at which it naturally resonates. After a few bounces of the pulse, this filtering process reduces that broad spectrum to a fundamental with some partials, and as the string rings, the balance of the various partials changes (they diminish). All the other frequencies that re not at the few natural resonances of the string die out. The rate at which they get filtered off is one of the things we perceive when we describe the sound of a piano. So, you are right in saying that "it vibrates", but there are some very important events that take place before the string settles into its slowly decaying vibration. I would even say that we react to those initial moments with much more interest. Incidentally, from a mathematical standpoint, it doesn't matter if the we are observing a pulse or a half cycle of a sine wave on the string. They both "reflect" at the rim and follow the same laws! If the rim is soft, the pulse/wave will partially be transmitted into the rim and the rest will reflect back into the soundboard. Vladan Terry wrote: Nawwwwwwwwwww. Your skipping rope is just like the speaking length of a piano string. You pluck it or whack it and it vibrates. Period. It vibrates. The length of time it vibrates will vary directly with the solidity/immobility of the speaking length terminations (a cast iron capo bar works better than a hunk of loose rubber). Similar with the soundboard. It vibrates. The more solid/immobile/massive the rim, the less the soundboard can vibrate the rim, and the less energy is lost at the rim. I really don't think there are things zipping back and forth and bouncing off this or that. I do know that it makes for great graphics in four-color brochures. That kind of thinking is consistent with the thinking that bridge wood/laminations need to have the grain oriented a certain way so the sound energy can pass through the bridge from the strings to the soundboard. Don't think so. Terry Farrell __________________________________ Do you Yahoo!? Read only the mail you want - Yahoo! Mail SpamGuard. http://promotions.yahoo.com/new_mail
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