> > This is a real can of worms. I'm still fishing, even if my license has > expired. Hi Carl, I know the feeling. > > 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. It was my understanding that the vertical bridge pin was intended to steer and encourage the string excursion to a vertical plane. The idea being to not dissipate string energy in lateral motion the soundboard couldn't use. I'll see if I can find whatever the heck I read to that effect tomorrow when I'm more awake. I don't think I imagined it, but I've been surprised by inaccurate memory before, so I'll have to wait and see. If the tradeoff between volume and sustain does depend on reorientation of the string excursion from vertical to elliptical, then we do have an apparent contradiction. At the moment, I'm tending toward the idea that if the departure point in the sound envelope from the attack to the dwell phase coincides with the transition from the mostly vertical to elliptical string excursion (and it is a pretty scenario), the Wapin seems to have a longer sustain because it delays that transition and extends the attack phase farther and more smoothly into the dwell phase by maintaining the vertical string excursion. Longer sustain may be, like most everything else, determined by perception rather than measurement here. In practice, I've heard pianos produce what I'd call both good volume and longer than average sustain. I suppose it depends on where you draw the line regarding volume. > > 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. That's the main reason I decided to write my own spectrum analyzer. I couldn't find anything commercially available that could give me the frequencies and amplitudes of partials peaks at various points in the time series of a sound sample. This isn't something that can easily be shown in a simple x y graph, since there's a "Z" axis in time that complicates things considerably. I think that what happens to the sound envelope of a produced piano sound over time, in terms of pitch and amplitude of partials, is easily as important as what a spectrum plot at any given point in time indicates. I doubt I can learn anything from the 39th partial (or beyond) of D3, even if I could measure and plot them, but without the time series measurements, I don't see that these plots tell us much. Ron N
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