---------------------- multipart/alternative attachment Carl: FYI, the patent holder of Wapin is the University of Cincinnati. The Wapin= LLP is only a clearing house for them on this. U of C would have to= reexamine this issue for the cost to change. I participated in Wapinizing of a 6'4" Knabe a few weeks ago. While doing= the work, we discussed how this works, why it helps, what's really= happening to the string. The bottom line is we don't know. It did make a= difference in the piano, but I couldn't begin to guess why. dave *********** REPLY SEPARATOR *********** On 2/17/01 at 7:08 PM Meyer Carl wrote: Thanks to Tom Cole, Ron Nossaman, and Richard Brekne for responding to my= post. This is a real can of worms. I'm still fishing, even if my license has= expired. I've just spent some time looking at the wapin.com site. They say that= wapin improves sustain. Okay, Ron, if you think that it is supposed to keep the string vibrating= vertically, then the sustain must be less. I'm not sure exactly what some of the parameters of the curves they show= mean, but one important factor is missing. The HP dynamic signal= analyzer, I'm not familiar with. I'll call HP Monday and find out. The= factor that is missing is time. The curve of the wapin piano in log mode= shows all partials out to number 39 and then stops. The note used is d3.= The 39th partial is 5726 Hz theoretically, but stretch may make it much= higher. Now, I would like to know the time that the reading was taken. From time= zero (when the hammer hits the string) amplitude of the partials vary= dramatically as they phase in and out. A plot of the level of partials= versus time would be very meaningful. A plot of each partial versus time= would get tedious, but a plot similar to Weinrichs giving the overall= loudness of the total signal would give us the answer to what the decay= would be. I suspect the graph shown of the wapin piano averages the amplitude over a= time period. For it to be meaningful we need to know what that time period= is. Richard, I wouldn't fret that you're not an acoustic professor. Nothing= will destroy your common sense faster than a formal education unless it= would being elected to public office. Do you really think that those that= have access to that fancy equipment have the mind to use it? Fascinating subject to be sure. My interest is fueled by the obscene= charge to license wapin. Nothing would delight me more than finding a way to equal or improve on= wapin with out infringing on their patent. Keep those cards and letters coming in. Carl Meyer David M. Porritt dporritt@swbell.net Meadows School of the Arts Southern Methodist University Dallas, TX 75275 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/49/ab/18/d0/attachment.htm ---------------------- multipart/alternative attachment--
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