At 22:06 -0500 6/7/10, Ron Nossaman wrote: >Concept alert! It's not the agraffe system that negates the need for >downbearing, it's that the board is stiff enough without it, to not >need it. The agraffe system adds significant mass to the system, >which would enhance sustain. Wouldn't it be cheaper to add a bit of lead to the bridge? How thick is this soundboard really? Does anybody know exactly? Somebody said about 1/8". Since a carbon-fibre/epoxy composite has a specific gravity roughly 4 times that of spruce, that would make the mass of the board (without bars) equivalent to a spruce board 1/2" thick. As to stiffness, I have no way of knowing, but to compare the two I would get a plank of spruce 2 feet long by 3" wide and 1/2" thick, hang a 50 lb. weight from the middle and see how far it went down. I'd then do the same with a 1/8" thick strip of the CF material of the same dimensions. Whichever went down less would win. I won't allow intuition to give me the answer because I have no familiarity with carbon fibre. JD
This PTG archive page provided courtesy of Moy Piano Service, LLC