---------------------- multipart/alternative attachment Ron Nossaman wrote: > >Seems like in the end we wont "know" for sure unless what you propose is > done Ron. > > * Right, and that might not tell us exactly what we're looking for either. > > >However there are indicators, and "informed" assumptions such as Eds that > >simply can not be discounted any more then you say they can be confirmed unless > >your "experiment" is carried out. > > * Well, I confess I deleted Ed's post before I got wrapped up in this, so > I'm not exactly sure what he said. Any chance you could send me a private > repeat? > Ok.. since a couple requests have come in for Ed McMorrow's comments on this subject, I will post them. Ron, he did not post it, I started this off by claiming to be able to hear a metallic tinge to pianos which use the V-Pro plate, and cited my own experience, and Ed's book as reference. You and a couple others jumped all over this.. grin., then I got a little indirect support from Robert A. Anderson who wrote directly from Ed's book. His post was as follows: This discussion reminded me of something I read quite a while ago. I quote from Edward McMorrow's THE EDUCATED PIANO (ISBN 0-929738-00-4), pp. 7,8: "The plates with the best acoustic properties are those in which a soft grey iron has been formed during the casting process. This soft iron damps metallic ringing sounds and hammer noise more than any other type of ferrous material. This damping ability is maximized when the casting cools slowly. Slow cooling also produces a soft metal, which significantly reduces breakage of the strings at the plate termination point....The most modern casting method is the automated vacuum-pattern process, which turns out very precise plates with awesome rapidity. This method has facilitated the development of a mass-production, assembly-line style of piano construction. All plates are precisely alike, and as little sand as possible is used to produce them. These plates do not damp metallic noise as well as the traditionally-made plates, and their harder metal causes premature string breakage. It seems a waste of resources and energy to produce pianos with these kinds of tone quality and serviceability problems. These casting methods are superb for producing economical internal combustion engine blocks, but for quality piano plates they are unacceptable." Comments, anyone? Bob Anderson Tucson, AZ Ed has three main points to make here. The first is his (hotly disputed <grin>) contention about the Vacuum pattern plate casts reduced ability to damp metallic noise. The second and third points are related.He states that the Vacuum method creates a harder plate, which causes problems particularily with the capo bar termination, String breakage results from the Capo bar being to hard. To counter that problem the capo bar is profiled with a wide rounded termination point which in turn undermines the pivoting function of the capos termination point, causing loss of string energy, excessive sting buzzing noise (especially as the capo bar wears) and excessive wear on the capo bar itself (due to the string no longer having a precise pivot.) I will quote a bit more from Ed's book if I may. "If the string is held to a precise termination point on the plate, which lets teh speaking length of the string flex the wire segment behind that point, we have a pivot termination. A pivot termination lets the string vibrate with less stiffness and more efficiency then a clamped termination. Most makers of fine pianos try to provide a pivot termination on the plate that precisely determines the vibrational axis of the wire and minsmizes the effect of wire stiffness. This is especially desirable and prevalent with the shorter treble strings. This feature on a grand piano is called the capo d'astro bar, and it is at this place where inconsistencies in the workmanship produce some varialbility in the pianos's ton quality and inharmonicity. The pivot termination of the capo bar gives the piano a greater dynamic range, Sicne the capo bar termination makes the string less stiff, the hammer can deflect the string more for a given blow then it can with a clamped termination. This is important in the treble, where the hammer strikepoint is near the capo bar and any increase in the hammers ability to deflect the treble strings will increase their dynamic range" Now despite the precision of the V-pro plate, the hardness neccessitates a movement away from this precise pivot point, which is detrimental to the sound. (ie either you widen and round off the bar, or you break a lot of strings). A termination point that is rounded off in this manner begins to behave more like a clamped termination point which interferes with the vibration of the string on both sides of the termination point. It also has the effect of increasing the stiffness of the string since the string cannot flex the string segment behind the termination point as well as it can in a precise pivot termination. "The vibrating part of the string must do all its flexing at that point internally, resulting in an increase in the string's stiffness, with some of the vibrational energy now producing internal friction in the wire." My point is that this situation produces a sound, which blends in with the total sound the piano produces. It colors the "Piano Klang" (as we say over here) if you will. And it does so in a way which is relatively easy to identify with the ear. There are two sound contributions involved I think, the one stems from the hardness and compensation for this in the capo bar inherent in the plate casting method. The other is less pronounced, but has the same colouring effect and extends over the entire piano. I have always assumed (after reading Ed's book) that this was due to the decrease in internal damping from the harder plate. Recent arguments from Ron and others have made me take a second hard look at this. It might be fun to resurface a C3's capo bar with a brass "V" bar, maintaining the same downbearing would have to be done, and then making sure the front duplex is detuned to inharmonic intervals from the fundementals of the strings in the capo sections. This should provide for an ideal situation (according to Ed again) for the fullest dynamic range for these strings. Hope this isnt too long.. God you guys make me read a lot.. <grin> Richard Brekne I.C.P.T.G. N.P.T.F. 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