Just to clarify: A lower spring rate means the board moves more easily or less? David Love davidlovepianos@comcast.net -----Original Message----- From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Ron Nossaman Sent: Friday, February 18, 2005 7:21 AM To: Pianotech Subject: Re: More CC vs RC questions was RE: Killer Octave & Pitch Raise >Well I meant that more as a question than a statement. One thing that >does interest me is how CC vs RC&S methods influence, either in design or >execution, the relationship between mass and spring rate and how that >might relate to proper hammer matching. Which system, for example, tends >to have a thicker panel? The CC board. >It seems that the CC panel is generally thicker in the center and tapered >toward the rim whereas the RC&S panel is slightly thinner and more uniform >in thickness (except maybe around the bass perimeter). Is that correct? Usually, but CC boards aren't necessarily tapered or diaphragmmed, and RC&S boards could be if you wanted. >Might not the difference in mass distribution of the CC panel explain >differences in hammer matching and potentially some tonal differences? I don't think so. >It seems that the CC panel requires a much denser and possibly less >flexible hammer than the RC&S board (at least in my experience). Whether >the tone production potential between the two with appropriate hammers is >net/net, is something I can't really answer but do wonder about. The >subject might point to some differences. > > >David Love I think it is mostly spring rate differences. The RC&S board will have a less progressive spring rate than the CC board (because of the lower panel compression), and probably a lower spring rate as well (though not necessarily). Because of this, I think the amplitude of vibration will be greater in the RC&S board, which might explain the different hammer requirements. An RC&S board with a laminated panel should have a more progressive spring rate (steeper gradient) than one with a planked spruce panel because of the relative incompressibility of the laminated panel. Ron N _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives
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