This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment 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. =20 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. =20 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 =20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/49/6b/0a/7e/attachment.htm ---------------------- multipart/alternative attachment--
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