----- Original Message ----- From: <Duplexdan@AOL.COM> To: <pianotech@ptg.org> Sent: October 25, 2001 11:14 PM Subject: Re: Duplex > Dear Dave, > > Does the Baldwin have a Duplex Scale? As currently designed and built, all grand pianos have what can be called a duplex scale. The phrase comes from the Latin 'duplex,' literally "twofold," from plicare "to fold." The question is, is the length of the duplex specifically and intentionally tuned to some partial of the fundamental string length? > Old Baldwins were made with triangular shaped oliquots, before the acu-just > system went into effect. All of these vintage pianos with adjustable oliquots > were designed to have a specific duplex scale tone that coordinated with the > tone of the speaking length. The moveablility of these oliquots was > incorporated to allow for this tuning process. Earlier Baldwin's had the back string rests pinned to a hole drilled in the plate. They are not movable. The change was made as much for cost-cutting reasons as to allow for 'tuning' them. There is no evidence that tuning the back scale with these string rests improved the performance of the piano, hence the subsequent change to the fixed vertical hitches. > Tuning the duplex scale of any and all of these pianos can unquestionably > improve the tone of the piano in particular regard to the quality of tone and > the sustain. Oh, I think there is considerable question about this. My own actual measurements revealed a slight increase in power at the affected frequencies during the initial attack period and immediately following but this was followed by a decrease in sustain as the energy coupled to the tuned duplex--the aliquot part--was (presumably) absorbed into the plate. Experientially, the tuned duplex system has also proven to be the cause of much unwanted string noise. It seems to boil down to a choice: with the tuned duplex system you might get a slight increase in initial attack volume at certain harmonics. In exchange you will have slightly shorter sustain and the increased probability of string noises. Or, you can design the soundboard such that sustain time is not--and does not quickly become--a serious problem and forget about the tuned duplex system and its attendent string noise problems. Personally, I prefer the latter approach. > May I remind you that this is not my idea; it is, was and always will be CF T > Steinway's, who has the original patent, 126848. What can I say? Lots and lots has been learned about the piano and its design since old CFT sat in front of a drafting table. Smart as he was, he wasn't perfect. Nor was the piano he created (in spite of the claim of certain of his descendents). It was--or should have been--just one stepping stone on the path, albeit a significant one. If our industry is to survive, however, we must learn from both his experience and our own and then go on from there. Del
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