By hybrid I mean with respect to crown formation. A pure RC&S board doesn't rely on any compression, or minimal anyway, a CC board is all compression and a hybrid is a combination of both, some compression and some rib crowning. Where the division is between RC&S and hybrid isn't that clear to me. I design ribs to support everything required and rib boards usually at 6.5% but if I go to 6% does that make it a hybrid since I'm adding a bit more compression? I don't know and to be honest, I don't worry about it too much. There's probably that much seasonal variation anyway in terms of after the fact performance. One thing I do notice about RC&S boards is that they are pretty tolerant of these differences. I've set up and heard pianos with rib scales that vary somewhat and the tonal differences are minimal. You can obviously overdesign a scale or underdesign it but within a range it seems to work without too much difference in tonal response. CC boards seem to be much more critical and it's not surprising since the crown formation must take place to a certain level or it doesn't' work well or doesn't last or both. But I digress. The other aspects such as rib material, tapering, cut-off bars, fish, rib arrays I think of as features and may or may not be components of any particular method. Trying to analyze strengths or weaknesses in a particular design is important in determining the why's and wherefore's of certain tonal characteristics or requirements, such as the modified strike line. Without a calculable and therefore repeatable method it's more difficult to determine whether you are making an apples to apples comparison. Clearly all methods are capable of producing good sounding pianos. The dependent variables of stability, longevity and predictability, however, may play out differently in each. Having had good results with RC&S boards even with various features included or omitted, and because of the high level of predictability, I tend to lean in that direction and don't yet see the need to investigate the nuances of compression crowning having heard too many poor outcomes using that method. Given other circumstances like unlimited time, money and resources I could see experimenting more with the hybrid method. At least there you can design the rib scale to provide the minimum required support and then rely on some compression to provide the rest. But, again, it introduces one other variable that's difficult to predict and so far I haven't seen a compelling reason to do that. But I remain open. I could win the lottery. David Love www.davidlovepianos.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of erwinspiano at aol.com Sent: Monday, February 08, 2010 7:44 PM To: pianotech at ptg.org Subject: Re: [pianotech] [pianotech ]Board & tone styles was hammer strike line David I haven't looked at the rib scale for a while but believe it had 16 ribs with curved cut-off,fish, belly brace like railroad tie and a small cut-off bar and the two bridges were separated, removing the ring. These were not laminated ribs but tight grain solid ribs or rib crowned. It was bellied at 6%. The rib ends were more conventional style cut-outs not the 1/3, 1/3, 1/3 thd arrangement of the pure laminated model Ron posted some time back. So if that's a hybrid so be it. Doesn't matter. many really liked that piano. Sweet yet visceral projection,enormous sustain. One thing for anyone to keep in mind to anyone listening to all the various experiences of any piano/board designer on the list or elsewhere is that it's important to factor in that each of us has a sound we are attempting to achieve. A different flavor, and it doesn't make one right or wrong but it does make it truly enjoyable to hear especially when great music is heard on them all. All the modifications are nice but the client has to sign onto that and pay for it. All that to say there are many factors to consider when doing this work and as David L pointed out in the choosing a hammer discussion ,there are even more in soundboard design or tone design. Wether a board is designed on a spreadsheet, by intuition and repition, or the seat your pants the end result is what speaks for itself. Dale Original Message----- From: David Andersen <david at davidandersenpianos.com> To: pianotech at ptg.org Sent: Mon, Feb 8, 2010 10:20 am Subject: Re: [pianotech] Hammer strike line. Was-----Yamaha Hammer Suggestion Let me jump in here...hopefully my brother Dale will too. The rebuilt "C" we brought to Rochester in 2006 has a RC&S board, and the tone in notes 68-76 got WAY better when we arced the line in, as Dale's pic showed. Whattup with THAT, Nossaman? Love and kisses....<g> DA On Feb 7, 2010, at 5:43 PM, PAULREVENKOJONES at aol.com wrote: Let me also say, Ron, that I was speaking to the differences between new soundboard installation with new hammers and what we find from the factory. If it is indeed a difference between soundboard panel construction, the evidence albeit being sketchy at best so far, it is an interesting distinction and well worth studying. And my point, again, was that factory production rarely allows for deviations from straight lines, particularly in hammer production and installation. Nor was I imputing a presumption on your part. Relax. Paul In a message dated 2/7/2010 7:16:15 P.M. Central Standard Time, rnossaman at cox.net writes: PAULREVENKOJONES at aol.com wrote: > I would posit that it's factory work, whatever the soundboard panel > structure. Efficient factory forefinishing has to presume much too > consistent a belly structure. Thoughtful deviations from a straight line > require time and care. I don't think it's primarily the soundboard. Meaning that in all the RC&S soundboards you've installed, you've never not had to deviate from a straight strike line? I'm not talking about assuming anything at all. "Whatever the soundboard structure" is the point, not factory presumption. Ron N = -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100208/984755f4/attachment-0001.htm>
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