----- Original Message ----- From: "Sarah Fox" <sarah@gendernet.org> To: "Pianotech" <pianotech@ptg.org> Sent: May 07, 2003 2:02 PM Subject: Re: Oops... Re: Unusual rib structure? > Hi Del et al., > > So these rib ties were somewhat of a "missing link" between the old > no-cutoff-bar design and the more modern cutoff bar construction??? Just > curious -- What was the evolutionary history, in a few sentences or less? > > Thanks! > > Peace, > Sarah (Sarah, you should by now know better than to ask me to whip something like this off in "a few sentences or less....") Your Wissner, like almost every other U.S. built, and now Asian built, concert grand traces it design origins back to the Steinway Model D. The Model D, in turn, traces its origins back to a synthesis of various pianos that formed the transition between the harpsichord/fortepiano and the so-called "modern" piano. Steinway actually introduced very little that was truly new and original. One of the things he brought forward was the large, open soundboard. (Yes, I know that many pianoforte's did utilize some form of soundboard cutoff. Most of those I've seen, however, were basically floating cutoff's however. Much like the straps used by Steinway, et al.) By the 1880s piano makers were just beginning to investigate the performance of various rib structures and soundboard shapes and configurations. And by this time the Steinway pianos had already became exceptionally powerful marketing and manufacturing successes. Market forces then, as now, dictated that there were more followers than leaders in the madness that made up the late 1800s and early 1900s piano business. Even though many builders were building better, and better sounding, pianos than anything coming out of the Steinway factory, they tended to get lost in the marketing and promotional wars that could, and did, become quite brutal. Many piano makers seem to have had a reasonably good grasp of the basic design principles that go into making a good, efficient soundboard system--we still occasionally see their products in our shops yet today. Well though out and often highly innovative work. But they didn't survive the marketing wars any better then than they do today. Ironically, even though Steinway marketing today carries on about the large soundboard/large amplifier foolishness, at one time somebody in the company clearly understood the value of a good soundboard cutoff bar--witness the shape of the soundboards in some of their early vertical piano designs. But this never carried over to their grands. At least not in the later production designs that have now become locked in tradition--some of their earlier vertical piano designs did have relatively substantial cutoffs. Pianos with purely compression-crowned soundboards tend to lose their crown and, hence, their ability to carry sustain, through the upper tenor and lower treble sections relatively quickly. (Relative, that is, in terms of piano life.) Both the addition of the so-called "resonator" strap (which stiffens up the soundboard assembly in an area which really should be infinitely stiff) and the upper bellyrail-to-rim strap are indications that somewhere back there someone in their design department understood at least the basics of why this was happening. These two devices both help, but do not solve, the real problem. Back in the late 1980s I was working on a small soundboard design and was able to look at the design I had come up with using a rather primitive modal analysis model. It was fascinating to watch the bridge move up and down while a mode in the forward bass corner simultaneously moved exactly 180º out of phase with it. Sound energy is simply transferred back and forth and is effectively cancelled. A second study done with a soundboard cutoff appropriately placed removed this area of the soundboard and increased the efficiency of the whole system. Del
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