Hi Terry, If there is no reflection of the energy in the string/rope/soundboard then it would cease to vibrate after the wave hit the rim/wall. Very short sustain directly proportional to frequency would be the result. Impedance would be zero. Some of the energy is absorbed and some reflected. We can control this to some extent by the selection of material and the amount of mass. It can not be otherwise without rewriting basic physics. If you don't like the rope then think about light waves hitting your rear view mirror. In the day time setting the silver of the backing on the mirror does the reflection--but in the night time setting the light reflects off the surface of the glass into your eyes. The surface of the glass is a poorer reflector--and this works out to be very useful in that particular application. At 03:29 PM 19/02/2005 -0500, you 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 > > >> Hi Terry, >> >> Take a skipping rope. Tie it to a concrete wall or some other massive >> object. Put a pound of tension on it. Now "pluck" it. Does the wave >> dissipate when it strikes the wall or does it "reflect" back from the >fixed >> end of the rope? I'm certain that it is part of the reason that pianos >with >> massive rims generally exhibit good sustain. >> >> At 11:31 AM 19/02/2005 -0500, you wrote: >> > What do you base this on? Does anyone know the >> >origin of this kind of thinking? >> > Not even Steinway marketing would agree with this: >> >Terry Farrell >> >> Regards, >> Don Rose, > > >_______________________________________________ >pianotech list info: https://www.moypiano.com/resources/#archives > > >-- >No virus found in this incoming message. >Checked by AVG Anti-Virus. >Version: 7.0.300 / Virus Database: 266.1.0 - Release Date: 18/02/2005 > > Regards, Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T. Non calor sed umor est qui nobis incommodat mailto:pianotuna@accesscomm.ca http://us.geocities.com/drpt1948/ 3004 Grant Rd. REGINA, SK, S4S 5G7 306-352-3620 or 1-888-29t-uner -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 266.1.0 - Release Date: 18/02/2005
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