> > So it might have been more accurate if I had written, "The design is > undeliberate, without plan." Or maybe not. Maybe the retrofitter worked > those numbers, listened to the finished piano, and was satisfied. But we > have no idea. Hi Bill, No, we don't, and that was part of the point. All we really know is that it is different than factory original, and different isn't necessarily bad. > > If we can get past the emotionally charged issues of duplexing, brand names > and the like....(Please forgive me for my careless, giddy enjoyment.) Nothing emotionally charged about this. I was just looking for explanations to your comments. > > I was looking forward to your comments on the issue of string backlength > distance (maybe even mechanical hinging, but I will stick to backlength > here). As I pointed out, I would leave it up to those more comfortable with > design, like yourself, to determine whether the change was significant. But > my point was that the backlength distance had increased from the original > duplex rest point to the hitchpin location, and that seemed to me to be a > design change. Sure it's a design change. I just wondered why you thought it was not a good thing. As Newton and Del have said, the vertical hitch is a better mechanical termination than an aliquot, because of the pivot, or hinging action. A tuned rear duplex isn't part of the vertical hitch scheme of things for at least a couple of reasons. The first, I've already mentioned. You can get all the back scale lengths of each plain wire unison approximately the same length within the unison with no tied loops by having three hitch pins in a row, parallel to the notch. This would give you one unison with shorter back length, and one with longer for each set of three pins. The difference in the back lengths being the difference between unison placement on the bridge between those two unisons. Now find a tuned duplex length for one of the unison pairs that satisfies the other. But, the hitches are probably too wide to do this, especially in the treble, so this probably won't work anyway. Alternately, two hitch pins, with a loop and a tie, could be used for each unison. Now all you have to do is locate the hitches, the bridge, and the plate accurately enough that everything falls into place and the duplex is automatically in tune. This isn't a likely possibility, which is why tuned rear duplexes aren't part of the vertical hitch scheme of things. What else is back scale length good for besides setting bearing angles? Soundboard freedom of movement. Short backscales restrict the soundboard, and restriction isn't the same as stiffness, so restriction isn't impedance either. That's what didn't compute. If the soundboard is working, the longer backscale is in my opinion and experience, a better option than a tuned duplex. It is my belief that tuned duplexes exist primarily as an attempt to compensate for soundboard design inefficiencies. With an efficient soundboad and long backscale, sustain and clarity are significantly improved despite the absence of the tuned duplex. If tuning an existing duplex helps it, great. Go for it. As for designing one into a piano, or restoring one that has been deleted, I consider it a step backward and would resist the urge. > > What I am guessing from your response is that in your view, in the total > scheme of things (re: Scott's modified Steinway "D"), the increased > versatility of the vertical pin outweighs the need to control backlength > distance (at least on the limited increased distance in this piano). Right. My opinion is that backscale lengths are typically entirely too "controlled". I like them long to let the soundboard move. > > And beyond the "D" to the generic retrofit, When would you want to begin to > make some kind of adjustment for the increased backlength resulting from the > placement of vertical pin retrofits at existing hitchpin locations? > How much difference would you be willing to "blow off" before it became > important in some way? > > Bill I'm not sure I understand what you're asking. I would like to be able to install vertical hitches in everything I rebuild, plate strength allowing. Having heard what a reasonably efficient soundboard design with a long backscale sounds like, I don't see any benefit to preserving the short tuned duplex. I haven't installed vertical hitches in a piano with an old compression crowned board, so I can't say one way or another how it compares in sound to the original tuned duplex. Mechanically, I'd expect the soundboard would suffer somewhat less compression abuse with humidity swings with the long backscale than being tied to a short duplex. The longer the moment arm, the shallower the loading gradient when the board and bridge go up in the wet season. All sorts of considerations. Ron N
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