Hi Richard, The simplest explanation is likely the most correct. If the bridge is not an initial an immoveable object then it does in fact move when a force vector no matter how small is applied to it. The contention was that the bridge moved because the soundboard moved. That is imho backwards. The string gets a kick to a higher energy state when energy is transferred to if from the hammer. This pulse whips along and encounters the bridge as one flexible termination point. It is interesting to note that the pulse is inverted in an upgright compared to a grand. This motion is then tranduced into the soundboard, which tranduces it to the air. Take a rope and fasten it to a hook on the wall. Give the rope a single "shake" and create a travelling wave along it. Now do the same experiment with a screen door spring at the far end. The spring will expand as the energy from the pulse hits it. If the bridge is a spring like structure then it would move away from the direction of that intial pulse and rock back and forth. It is held at the root by the soundboard. Where would the energy go if the impedance of the bridge/soundboard was non existant (or zero)? All the energy from this single pulse would be disapated, and there would be a short loud sound. Lots of questions and few answers because no one has looked? At 12:10 AM 12/24/2001 +0100, you wrote: >Don Rose wrote: > >> Hi Richard, >> >> Are you suggesting that the energy does not tranduce through the bridge to >> the soundboard, or that the bridge is initially an immoveable object? > >Of course not Don. Where on earth in the words I wrote could you pull that one >out ? Regards, Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T. mailto:drpt@sk.sympatico.ca http://us.geocities.com/drpt1948/ 3004 Grant Rd. REGINA, SK S4S 5G7 306-352-3620 or 1-888-29t-uner
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