| To me, the transducer argument *de-couples* the strings and | the soundboard--(by doing this "transducing," taking one | thing and making it another). That goes against everything | I've read about piano acoustics. This would rather depend on what you are reading. To be sure, Wm Braid White wrote eloquently, if some what confusingly, about the power of resonance, that mysterious property he found in certain materials-namely spruce-to amplify the sonorous quality of the strings. Thus he was able to state that "more resonating power is required for the relatively weaker treble strings than for the relatively stronger bass strings." In this way he was able to explain why piano builders had found it necessary to make their soundboard panels thicker in the treble area and thinner in the bass area. In 1909 White did not yet have to contend with the so-called "Diaphragmatic" soundboard. But that was then and this is now. So far as I know there is no modern writer who speaks of the piano soundboard system as an amplifier. In the Five Lectures series, Klaus Wogram writes, "The soundboard transforms the mechanical vibrations into radiated sound." Benade (Fundamentals of Musical Acoustics) discusses the soundboard as a "two-dimensional driven plate." This plate, by means of forced vibration (the stored mechanical energy of the strings) creates sound (acoustical energy) by means of the resulting physical motion. For Fletcher & Rossing (The Physics of Musical Instruments) it is described thus: "Acoustically, the soundboard is the main radiating member in the instrument, transforming some of the mechanical energy of the strings and bridges into acoustical energy." It might be helpful to try a little experiment. Locate a thin piece of wood several inches wide and a few inches long. Now locate a small hammer. With the thin-and so far silent-wood panel in one hand tap its surface with the hammer. Sound (acoustical energy) is created when the hammer strikes (mechanical energy) the wood panel. It is an impulse sound, of course, and it dies out very quickly but if you could make your hammer strikes fast enough (vibrating mechanical energy) the resulting sound would become a tone (continuous acoustical energy). By striking the piece of wood with the hammer you created sound, or acoustical energy. It wasn't free-you had to invest mechanical energy to get it-but that acoustical energy was not amplified from anything. It was created. Now picture the soundboard bridge being struck repeatedly and rapidly by a series of tiny hammer blows (the vibrating string) and picture the soundboard responding to those blows by slight movements. Because of its large size the soundboard will create sound-acoustical energy. This is not amplified sound; there was no original sound to be amplified, only the mechanical energy stored in the vibrating string. (And let's not quibble over the minute amount of sound created by the vibrating string(s). This is completely overwhelmed by the wash of acoustical energy coming from the soundboard.) Semantically we could, I suppose, quibble over whether the piano soundboard system should be called a transformer-".a thing which transforms something"-or a transducer-"a device for converting variations in one physical quantity, as pressure, brightness, etc., quantitatively into variations in another, as voltage, position, etc." (Both from the OED) What we cannot do, at least not if we want our language to meet even minimal standards of technical accuracy, is call the piano soundboard system an amplifier. Over the past century our understanding of how the piano works has evolved considerably as has the language used to describe and discuss it. Words and their meanings in a technical community-and both CAUT and PianoTech are technical communities-are important. They convey certain defined technical meanings to the participants. These are not casual discussions over the Sunday barbecue with Aunt Matilda. To misuse technical words or to apply one's own meanings to them-even if that usage was in vogue a hundred years ago-can only mislead and confuse the reader or participant. ddf -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20090513/899885f3/attachment.htm>
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