Hi Mark and others. Some interesting stuff written on this thread for sure. As to the below.... I have to raise my finger in the air in question. It was my understanding that and increase in sustaing if strings are slightly decoupled has been already shown to be true and above question. Very similiar to the basic tradeoff between sustain and power problems. Its not a matter of increasing or decreasing energy... its a matter of how it is to be distributed through the system. I suppose you have read the article by Gabriel Weinreich http://www.speech.kth.se/music/5_lectures/weinreic/weinreic.html This said... I believe that unisons in a very real sense can not ever achieve a perfect coupled motion in the first place. There is always at the minimum at least some barely discernable wavering. I wouldnt necessarilly call this instability beating per se... but unisons are never clean in the absolute sense that is meant in the physics models drafted in such articles as the above. So just how much a tradeoff between sustain and power (unison cleanness as it were in this instance) one can achieve is an open question as far as I can see. As for the Bluthner extra string... I am entirely unconvinced it does anything to increase sustain one way or the other. It can be used to colour the over all sound of the unison and intervals. I've often surmised it may have some affect of supporting crown slightly. But increasing sustain ?? Well I've never carefully measured and then removed the entire set of extra strings to find out... so I suppose I should be cautious in making any declarations. Cheers RicB -------------------------- Mark Schecter writes: OK. So the treble notes decay more quickly than lower notes, and we would like to slow that decay, IOW increase the sustain time, and we think maybe we can trick the piano into doing our bidding by "tweezing" the unisons. I say that it doesn't work, and that no matter how we tune or detune unisons, that the best we can do is _create the illusion of greater sustain_. We can no more make the note last longer than the input energy through the string-bridge-board-air makes possible, than we can make water flow uphill.
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