>... why not a piano related topic? Why not indeed? >Are there any good books out there that give basic information >for a neophyte piano technician on simple things concerning piano >design and construction? Not to my knowledge. > Things like: what is the purpose of mutiple >strings in a unison. Does it increase sustain, loudness, or decrease >attack noise, etc. This one is simple, obvious after the fact, and useless for anything more sophisticated than the basic mechanics of the system. Soundboard response is governed by the balance between the impedance of the soundboard assembly and the mass, tension, downbearing, and frequency of the strings at any given point in the scale. Low in the scale, the strings are few (ie one per unison), and offer a high mass to move the soundboard at a low frequency as well as a broad contact hammer area to minimize hammer wear. Changing to bichords, the string mass transition from monochords is (hopefully) reasonably seamless, and the narrower hammer contact area of each individual string is lessened, while the total area is doubled by the second string, so the total contact area is at least somewhat similar to the monochords. Meanwhile, the mass of the bichords at the monochord/bichord transition is similar enough to the previous monochord that (if you paid adequate attention to the unison tensions), you not only won't hear the transition, but the hammer wear rate won't be appreciably different across the break either because the unison string contact area to the hammer will be similar. The same criteria applies at the transition between wrapped bichords and plain trichords. Considering also that two strings are louder than one, and three are louder than two (balancing unison impedance against soundboard assembly impedance at that point in the scale), the shorter string length unisons with less mass will need more strings than the longer string unisons with more mass. Like I said - simple in principle. Translating the whole mess into a workable soundboard assembly/rib scale/string scale is a tad more complicated. > How do you obtain a particular harmonic balance/ >sustain for a note played ppp through fff on a well designed piano >through voicing. Here's where Poker goes up. Voicing is only effective in the context of what the string scaling and soundboard assembly design will give you to play with. In other words, it ain't the voicing that makes the difference, it's the soundboard and string scale that defines the limit of what you can do with voicing. Voicing is just disaster control, in virtually all instances. My experience is that voicing is for the most part unnecessary when the string scale and soundboard assembly design are compatible. >I am not aware of a proper treatise on such >matters. If anyone could give a hint on where to find the knowledge that >has been secured on any of these and like matters, I would be most >appreciative. As far as I know, it doesn't exist except as a do it yourself assembly puzzle in the pianotech archives. Volumes have been written about just this sort of stuff, but you will have to fit the pieces together for yourself to make any sense of it. Ron N
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