Hey Robin, I'm glad this post was off-list! :-) Just kidding. Been there, done that! Avery At 11:57 AM 12/12/02 -0800, you wrote: >Hello Sarah, > I realized that I had misunderstood your description of the > situation with >your piano - I had been thinking that you were embarking upon a rebuilding of >it. If you will send back to me the numbers of the notes where the wires are >missing I can probably provide the correct wire size. > Another way to determine this is to look at the adjacent unison. If > there >is no single involved then they will come in sets of two - by this I mean >there >must always be the same wire on at least two unison due to the fact that the >looping takes one wire onto the bridge to serve as a string for the next >unison >and the other two in that unison must match it. Sometimes, it is possible >with >a little detective work to measure the adjacent unison and reach a >conclusion as >to the correct wire that is missing. However, if you will just send me the >number of the key, starting at 1 and counting up from the bottom, I will >likely >be able to find the size that was most likely used, at least, on a Steinway >grand. >Regards, Robin > >Sarah Fox wrote: > > > Hi Robin, > > > > I don't think we disagree. <smile> > > > > So you've rebuilt two Wissners?! How similar to mine? Were they 9' > > D-clones, by any chance? Circa 1933? I would love to know whether there > > are pins beneath those aliquots. It sounds as though there aren't. If you > > say they're not supposed to be tuned to sevenths (not ninths, actually), > > then the plates must have been moved. > > > > Also, do you know the original string diameters throughuot the tenor and > > treble? Avery Todd sent me some measurements on a Steinway D which > I'll use > > as a first-order approximation in the absence of any other data. > > > > Thanks for any info you can provide! > > > > Peace, > > Sarah > > > > ----- Original Message ----- > > From: "Robin Hufford" <hufford1@airmail.net> > > To: "Pianotech" <pianotech@ptg.org> > > Sent: Thursday, November 21, 2002 2:59 AM > > Subject: Re: S&S D Duplex > > > > > Sarah, Gordon, and Dan > > > Yes, this is the sort of energy transmission I am trying to describe > > > here, although, the point I repeatedly make is that the transverse > > > behavior on the string is transduced mechanically by the terminations to > > > a forced, not free longitudinal wave and that means the frequency and > > > amplitudes are those of the forcing function. This is, in fact, what it > > > is, and that is the normal, ordinary, sound wave or mechanical wave > > > progation. They are, in essence, the same. A free longitudinal wave > > > is almost irrelevant to piano sound. > > > Additionally, through reflexion, constructive and destructive > > > superposition occur in the duplex as they do in the board thus creating > > > transverse behavior which, though resonance, becomes much greater in > > > amplitude than is the amplitude associated with a simple, free > > > longitudinal vibration. > > > I have rebuilt two Wissner's; they have the same duplex > > > arrangements as is found in Steinways, or at least, these did. I can > > > hardly believe, Sarah, that your piano should have a duplex tuning to > > > the ninth. Considering the incompentant restringing your have > > > described, this is most likely continuing careless on the part of the > > > restringer. > > > I have always been careful to tune the duplex on pianos I have > > > rebuilt, yet my experience is similar to Del's: I can't really tell a > > > significant difference. I consider myself to be neither a duplexephobe > > > nor a duplexephiliac as the duplexephone, in my experience, has been > > > somewhat duplicitous. (Thanks to Phil F for this little digression, > > > after reading his amusing description duplexaholic) > > > Regards, Robin Hufford . > > > > > > gordon stelter wrote: > > > > > > > And it seems to me that the more rigid a body, the > > > > more rapidly "shock wave" vibration would pass from > > > > one end to the other, as long as it was of uniform > > > > density to avoid internal damping. So if someone had a > > > > very stout steel rod, say 2" in diameter and 6 feet > > > > long, and tapped on one end, more vibration would pass > > > > through to the other end than on a rod which flexed, > > > > thereby dissipating the energy into the air, and > > > > losing it as heat in the internal flexion. And this > > > > longitudinal transmission would be virtually > > > > unnafected by bearing points, clamping, etc. Is this > > > > the sort of energy transmission we are speaking of > > > > here? > > > > Gordon Stelter > > > > > > > > --- Robin Hufford <hufford1@airmail.net> wrote: > > > > > A correction of one of the, unforntunately, > > > > > frequent typos in postings of late. rh > > > > > > > > > > There is a reasonable analogy to drawn between the > > > > > flexural, bodily, > > > > > behavior of the tines of the fork and the > > > > > transduction of this to a cyclic > > > > > vibration or stress wave passing through the(STEM > > > > > )(corrected version) and the > > > > > flexural, standing waves on the string which are > > > > > transduced similarly by the > > > > > terminations at the > > > > > bridge/board and agraffe/capo interface. > > > > > > > > > > Robin Hufford wrote: > > > > > > > > > > > Hello Sarah, > > > > > > The "pseudo-longitudinal wave" is, in fact, a > > > > > true longitudinal wave but it > > > > > > is a forced vibration and contains the > > > > > frequencies of the forcing function. It > > > > > > is the normal mechanical wave or density > > > > > fluctuation passing through a medium > > > > > > as the particles of the medium oscillate around > > > > > their equilibrium positions in > > > > > > the waveguide which, in this case, is mostly the > > > > > continuing portion of the > > > > > > string threaded across the bridge, the bridge > > > > > itself, the bridge pins, or the > > > > > > part of the wire passing through the agraffe, > > > > > along with the agraffe, Capo bar > > > > > > and plate. This is not a variation in tension > > > > > but, rather, again, a density > > > > > > fluctuation passing through the medium with a wave > > > > > velocity which is a function > > > > > > of the inertial and elastic properties of the > > > > > medium itself, imposed upon this > > > > > > is the frequency and extent or lack of > > > > > periodicity. > > > > > > This can be viewed in another way and that is > > > > > as a state of cyclic stress > > > > > > passing through the medium. > > > > > > Not to be too repetitive on the list as this > > > > > has been thoroughly explored > > > > > > in the threads referred to earlier, although > > > > > vehemently disagreed with by others > > > > > > here on the list: this can be easily comprehend > > > > > by considering the behavior of > > > > > > a tuning fork. The tines oscillate back in forth > > > > > at a right angle with regard > > > > > > to the stem. Their flexural, oscillating, bodily > > > > > behavior is mechanically > > > > > > transduced to a cyclic stress, strain, or density > > > > > fluctuation, as you will, > > > > > > which is a forced vibration passing along the > > > > > bass and stem of the fork. When > > > > > > placed in contact with the bridge, and it matters > > > > > little where, this vibration > > > > > > then passes into the bridge and board where > > > > > reflexion, superposition and its > > > > > > attendant interference, both positive and negative > > > > > create distortional and > > > > > > dilational waves in the board itself; momentum is > > > > > then radiated away as acoustic > > > > > > radiation. Precisely the same thing happens with > > > > > the vibrating string itself: > > > > > > the standing waves are enabled by the, > > > > > essentially, rigid termination > > > > > > mechanisms which transduce the strain energy > > > > > associated with the standing wave > > > > > > behavior in the wire into forced longitudinal > > > > > vibrations at the terminations. > > > > > > There is a reasonable analogy to drawn > > > > > between the flexural, bodily, > > > > > > behavior of the tines of the fork and the > > > > > transduction of this to a cyclic > > > > > > vibration or stress wave passing through the tines > > > > > and the flexural, standing > > > > > > waves on the string which are transduced similarly > > > > > by the terminations at the > > > > > > bridge/board and agraffe/capo interface. > > > > > > The longitudinal wave energy, at the > > > > > frequency of the forcing function, > > > > > > passes into the bridge with out need of flexion, > > > > > although I have never argued > > > > > > that flexion is completely absent for several > > > > > reasons, and, crosses the bridge > > > > > > and continues along the duplex where again, > > > > > reflexion and superposition create > > > > > > audible, tunable vibration. > > > > > > I don't know whether these segments increase > > > > > sustain or not, although, I > > > > > > have no doubt that, in some cases, the difference > > > > > in total sound, as I said in > > > > > > the previous post, increases the perceptibility of > > > > > the note produced by the > > > > > > speaking length, possibly in a kind of > > > > > gestalt/figure interaction. This would > > > > > > be very difficult to pin down, accurately. > > > > > > This view, which is rather unpopular here, > > > > > requires a subtle distinction to > > > > > > be drawn between the flexural, bodily behavior of > > > > > the vibrating portion of some > > > > > > object or structure, and the nature of wave > > > > > motion, or, again, localized > > > > > > density fluctuations which pass through a medium > > > > > and do not require actual > > > > > > bodilty motion of the medium itself for their > > > > > propagation. These are just the > > > > > > normal, ordinary mechanical waves encountered > > > > > everywhere. The function of the > > > > > > soundboard and bridge stabilize the endpoints of > > > > > the string and allow the > > > > > > transduction through mode conversion of strain > > > > > energy of the standing waves > > > > > > which are of course, primary, but, in another > > > > > sense secondary phenomena. > > > > > > Regards, Robin Hufford > > > > > > > > > > > > Sarah Fox wrote: > > > > > > > > > > > > > My other attempted post, accidentally directed > > > > > to Robin Hufford in > > > > > > > private... > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > From: "Sarah Fox" <sarah@gendernet.org> > > > > > > > To: "Robin Hufford" <hufford1@airmail.net> > > > > > > > Sent: Monday, November 18, 2002 3:35 AM > > > > > > > Subject: Re: S&S D Duplex > > > > > > > > > > > > > > > Hi Robin, > > > > > > > > > > > > > > > > OK, thanks for explaining the "longitudinal" > > > > > wave to me (i.e. which isn't > > > > > > > > really a longitudinal/compression wave at > > > > > all). Steinway's "longitudinal" > > > > > > > > wave, if I understand you, is little more than > > > > > the variation in tension of > > > > > > > > the wire as it vibrates, resulting in lateral > > > > > forces (in direction from > > > > > > > > tuning pin to hitch pin) across the bridge. > > > > > Correct? I would think there > > > > > > > > must also be some transverse (e.g. vertical) > > > > > vibration in order for > > > > > > > cyclical > > > > > > > > tensional variations to result in any sort of > > > > > string vibration. Really I > > > > > > > > view the pseudolongitudinal wave (as you > > > > > explain it) as yet another aspect > > > > > > > > of a transverse wave. Of course I'd need to > > > > > think about it... and my > > > > > > > brain > > > > > > > > doesn't work all to great at this time of > > > > > night. <yawn> > > > > > > > > > > > > > > > > I suppose I would still echo Del's concern: > > > > > Does a pseudo-longitudinal > > > > > > > wave > > > > > > > > travel to the duplex segment through the wire > > > > > or through the bridge? I > > > > > > > > would argue that unless the string slips > > > > > freely on the bridge pins, which > > > > > > > it > > > > > > > > clearly doesn't, that the bridge would have to > > > > > move in order for > > > > > > > vibrations > > > > > > > > to pass into the duplex segment. I don't > > > > > think there's anything magical > > > > > > > > about it. On either side of the bridge, we're > > > > > still talking about > > > > > > > > garden-variety transverse waves, which are > > > > > tunable in every sense to which > > > > > > > > we have grown accustomed. > > > > > > > > > > > > > > > > As I see it, the fundamental questions are > > > > > still: > > > > > > > > > > > > > > > > (1a) Does an unmuted duplex segment increase > > > > > sustain? (1b) Does the > > > > > > > tuning > > > > > > > > of an unmuted duplex segment affect sustain? > > > > > > > > > > > > > > > > (2a) Are the tonal effects of a duplex segment > > > > > desirable? (2b) How does > > > > > > > > this differ between tuned and untuned? > > > > > > > > > > > > > > > > The first question can be answered > > > > > quantitatively. The second is a > > > > > > > > subjective matter, not unlike the age-old > > > > > argument as to whether a large, > > > > > > > > echoing concert hall sounds better than an > > > > > "anechoic" chamber -- or vice > > > > > > > > versa -- or some compromise inbetween. > > > > > Different strokes for different > > > > > > > > folks. > > > > > > > > > > > > > > > > Anyway, thanks for explaining what is really > > > > > meant by this "longitudinal > > > > > > > > wave" thing. It makes much more sense now. > > > > > > > > > > > > > > > > > === message truncated === > > > > > > > > __________________________________________________ > > > > Do you Yahoo!? > > > > Yahoo! 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