---------------------- multipart/alternative attachment Hi Ron. I'll try and respond in one bit at the top here instead of mixing up comments all over the place below. 1st off... let me just say that I really take no position about which type of board is <<better>> then the other in any sense of the word. My interest in all this is two fold. One to simply report what I see and hear from others in the industry, and two, to try and weed out some of the false or overstated claims made by anyone for any reason. I'm sure you can understand this last bit as you immediately raise the credibility issue with regard to the reported views of Mr. Steingręber. And to be sure... does he really have an experience base that qualifies him to pass such judgment ?... Is he being purely objective ? Does he build CC boards because of that, or is he just justifying the CC board method in anyway he can ? I suppose we could ask the same questions of any particular builder, and no doubt we do. But in most cases, it will be hard to establish just how much they do or dont know about all the ways of building a panel, and the consequences of each. We can assume that a successful builder at least knows how to build a useable instrument though I think. In any case, I feel I am rather dispassionate about the "whose right" side of all this, being much more interested in "what's right". And its in that spirit I bring up much of what I do. For example I find it alarmingly odd that the argumentation presented here in favor of RC boards is so very convincing, yet so many of the most important manufactures seem to employ some form or another of CC board. The Japanese have used enormous resources on piano building research (that they keep to themselves largely). I've seen the layout and size of the Petrof research facilities, and talked to two acoustics professors they have employed about the general scope of their research. I could go on... but I just have to assume these and other manufacturers know something of these matters and base their decisions on some significant degree of understanding. So, I ask, and I prod, and I no doubt tick off more then a few... because I am curious and I want to know, despite whatever limiting factors I have to deal with. One thing comes clear nearly immediately. Piano builders and piano technicians are most often very passionate about the correctness their own methods. We regularly overstep what we really know in attempts to justify our views, and that requires of each of us a healthy portion of both humility and patience with each other.... that is ... if we really want to learn anything from each other. Over to the technical issue you bring up... I'd love to hear more about spring rate, and how that is supposed to affect the acoustics of the panel. Some would have it that its only the mass and stiffness of the assembly that are in the end important. So by all means go for it. As for Steingręber pianos... These past months have seen several members of this list offer some pretty wonderfully sounding praise for his instruments, both from an artistic point of few and in the course of some of the design issues discussions. So naturally I was very much looking forward to looking them over a bit. Nice puppies to be sure. But I have to admit I find it then fascinating to find he takes the position he does on the soundboard issue... and that they take the CC panel method to the extremes they do. Cheers RicB Overs Pianos wrote: >> At 12:13 AM +0200 20/10/03, Richard Brekne wrote: > >> > >> . . . I also asked [Mr Steingręber] about the criticisms of CC >> panels, and Rib crowning as > >> an alternative. His response can be summed up by saying that CC >> panels >> are quite dependable and have outstanding longevity characteristics >> as >> long as they are contrived with the proper care and knowhow. And >> concerning the Rib crowned panel, his position was that these were >> acoustically inferiour.... tho I didnt get time to really nail him >> down > >> on a more specific reasoning for that opinion. > > This leads to a further question. Has Mr Steingręber actually built > an RC board to establish the view that he holds, or is it that since > he doesn't use rib crowning, that it is better for his production > credibility to discount the technique out of hand? I find it highly > unlikely that one construction technique would have a propensity to > produce a superior tone over the other. The real advantages that I see > with RC&S construction are repeatability and longevity. The spring > rate of a panel must surely influence its response. I suspect that the > spring rate of either type would be a more critical factor that the > construction method used (in the short term at least). I recall Ron > Nossaman mentioning this some time back, but no-one seemed to take it > up at the time. I believe it would be possible to build either a CC, > an RC or an RC&S panel with whatever spring rate the maker desired > (the 10 mm thick panels we see in the KG series compression crowned > Kawais, must surely have been used to achieve a higher spring rate - > with hopefully longer sustain - than those CC instruments with thinner > panels. We have a KG5 coming in for a rebuild next week - the earlier > type with the Oak belly rail and back beams - the bridges will have to > go since they're not quarter cut, but the panel remains an unknown > until it is investigated further). Furthermore, since the CC and RC > approach are entirely different in their method of supporting crown, I > failed to see the utility of the discussion which ensued a few a weeks > ago, when there was much speculation about the relative stiffness of a > pair of identically dimensioned CC and RC&S boards. We have just > completed the construction of a pure RC&S laminated panel sound board > (while our previous instrument - no. 3 - had a board which was very > close to pure RC, this new sound board features a completely new rib > design - patent pending). The strings should be going on by the second > week in November. I will report to the list with my first impressions > when I get it together. We have been building piano no. 5 alongside > no. 4. But I have held off on the construction of the sound board for > no. 5 until I hear no. 4 'in song' - just in case I decide to change > the spring rate. BTW Dale, your posts have been interesting. And David > L., I use a similar technique as the one you described for replacing a > bridge. Ron O. > > -- > > OVERS PIANOS - SYDNEY Grand Piano Manufacturers > _______________________ > Web http://overspianos.com.aumailto:info@overspianos.com.au > _______________________ -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html http://www.hf.uib.no/grieg/personer/cv_RB.html ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/0e/30/87/40/attachment.htm ---------------------- multipart/alternative attachment--
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