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Joined: Sep 2004
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It was my understanding, from Udo Steingraeber, that the wood veneer option is purely for cosmetic purposes, in case you feel the black color of the carbon fiber is too nontraditional for you. You may be correct, but if that was the goal, why would they put the wood veneer on the bottom of the soundboard and leave the carbon fiber exposed on the top for all to see?
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Had a Luis & Clark carbon fiber cello. It was too bright for me. The designer liked it that way.
My previous piano was a Kawai with carbon fiber action. My present piano is a Mason Hamlin with WNG action.
Want to hear and play a piano with a carbon fiber soundboard. Would be great to have in the Western US where the air is very dry.
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What precisely, in terms of material properties, is desired in a soundboard? A certain axial/torsional stiffness? A combination of stiffness and low density?
Wood just seems like a terrible material for anything... you can modify it easily but that's about it.
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What precisely, in terms of material properties, is desired in a soundboard? A certain axial/torsional stiffness? A combination of stiffness and low density?
Wood just seems like a terrible material for anything... you can modify it easily but that's about it. At least in part, you would want the stiffness to weight ratio of the soundboard assembly to be within some limits. Of course, things quickly get more complicated--the piano soundboard system evolved using a highly anisotropic material, namely wood; the array of ribs helps stiffen the board to make up for the panel's very low across the grain stiffness. The subtleties of how this combination of ribs and anisotropic panel contribute to the sound may be of some sonic importance--only modeling and testing would confirm. Also, wood is a fairly highly damped material--much more so than metal or normal carbon-fiber panels. No doubt, this characteristic affects the sound. Of course, with enough testing and development, someone could come up with a replacement for wood. The real question is what would the development costs be, and what would the recurring costs be?
Last edited by Roy123; 01/25/13 09:09 AM.
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The veneer is on top of the sound board. I did not look under the grands.
I was told that the only reason for the above is to cover the carbon fiber which looks like a smooth woven black "sheet"; i.e. cosmetic.
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The veneer is on top of the sound board. I did not look under the grands.
I was told that the only reason for the above is to cover the carbon fiber which looks like a smooth woven black "sheet"; i.e. cosmetic. The only one I've seen is the one at Larry Buck's shop, and the top of the soundboard is carbon fiber.
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Of course, with enough testing and development, someone could come up with a replacement for wood. The real question is what would the development costs be, and what would the recurring costs be? Also the question is what engineering tradeoff did you buy with the new material. Every engineering improvement will be tend to "fix" a long standing problem or challenge. However these improvements are almost always accompanied by new, sometimes unintended engineering challenges. Roy mentions the internal damping as one. Another would be that though carbon fiber does not react to RH changes, as a plastic, how reactive will it be to temperature change?? Composite Plastics can expand/contract with temperature change. I don't know the physics but suspect some pickiness with regard to temperature. Do normal occasional 10-15f deg swings throws a monkey into mix?? Jim Ialeggio
Last edited by jim ialeggio; 01/26/13 04:27 PM.
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At least in part, you would want the stiffness to weight ratio of the soundboard assembly to be within some limits. Of course, things quickly get more complicated--the piano soundboard system evolved using a highly anisotropic material, namely wood; the array of ribs helps stiffen the board to make up for the panel's very low across the grain stiffness. The subtleties of how this combination of ribs and anisotropic panel contribute to the sound may be of some sonic importance--only modeling and testing would confirm.
I agree, it seems like you'd have to go away from the current rib setup to attain the same acoustic qualities. Playing around with the structural layout (and composite thickness/layup) in a vibration FEM program would be fun.
Another would be that though carbon fiber does not react to RH changes, as a plastic, how reactive will it be to temperature change?? Composite Plastics can expand/contract with temperature change. I don't know the physics but suspect some pickiness with regard to temperature. Do normal occasional 10-15f deg swings throws a monkey into mix??
No, in fact quite the opposite. Carbon fiber (woven, in an epoxy matrix, with plies in different directions) has a very low thermal expansion coefficient. In fact wood expands ten times as much as carbon fiber. Wood is already basically a composite due to the grain. The thermal expansion and stiffness vary quite a bit depending on the direction (with or against the grain, or radially). Carbon fiber can have its properties tailored based on ply layup. I'm really curious about the cost of the wood used in soundboards. Since it's slow growth wood it has got to be pretty expensive, and will only get more expensive in the long run. CFRP is expensive but is coming down in price as usage increases (aerospace industry).
Last edited by KillerCharlie; 01/26/13 08:28 PM.
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I just ran a little "heat" test on a WN&G hammer shank. The shank has the thickest wall of all shanks WN&G offers. I warmed up my convection oven to 170 Degrees F. Measured shank diameter at room temp was .189" (I measured 1' in from the hammer end and oriented the micrometer parallel with the striking axis of motion, The extruded carbon tubes that form the shank are a little out of round), measured overall length with calipers from inside of fork to end of shank, (did't record value since I left caliper at pre-heat dimension).
After 15 minutes I removed shank from oven and measured diameter at same location it was .189", overall length was exactly as before heating.
Of course more refined techniques would reveal any more subtle movement. But this test jibes with the engineering reports about composites I am familiar with.
In a seemingly infinite universe-infinite human creativity is-seemingly possible.
According to NASA, 93% of the earth like planets possible in the known universe have yet to be formed.
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Hi Ed...
My comment was inspired by my memory of the Steingraber phoenix w/carbon fiber board at the 2011 KC convention. The air conditioning system was playing havoc with all the pianos. However, in the entire hall, the only piano that was seriously out of tune was the Steingraber.
Obviously there could be many more mundane explanations of this, such as Steingraber's tech was AWOL or awash in the lounge. One would assume the sales people who brought such a unique instrument before a high profile gathering of way-picky-conservative piano nerds, nerds who would be looking for flaws, would be paying attention to this sort of thing.
It leads me to wonder why the ambient reactivity was so strong, given the stability of the carbon fiber, lack of humidity driven migrating bridge pins, etc.
Perhaps Larry or someone with a more intimate day-to-day relationship to this creature could comment on its relative stability in normal and/or fluctuating ambient conditions.
Jim Ialeggio
Last edited by jim ialeggio; 01/27/13 08:53 PM.
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I had a chance play the Steingraeber piano a couple of weeks ago and I was pretty astounded. I have played a lot of keyboards and pianos over the years and have to say I was completely amazed by the action and the tone of this piano. The action was so nice that I felt completely connected to the instrument like I have rarely experienced. The carbon fiber soundboard created a sound that to me was very crisp and rich. Interestingly I found the lower mid-range to be a little thinner, with a slightly different timbre than other pianos. I do not mean that as a negative at all since I find many pianos to seem kind of "muddy" sounding if there's a lot going on in the left hand. I heard much more clarity in that range than I am used to hearing and it was very pleasing to me. I really appreciate the opportunity to play this wonderful instrument!
Last edited by davepowers; 02/03/13 01:13 PM.
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Hi Ed...
My comment was inspired by my memory of the Steingraber phoenix w/carbon fiber board at the 2011 KC convention. The air conditioning system was playing havoc with all the pianos. However, in the entire hall, the only piano that was seriously out of tune was the Steingraber.
Obviously there could be many more mundane explanations of this, such as Steingraber's tech was AWOL or awash in the lounge. One would assume the sales people who brought such a unique instrument before a high profile gathering of way-picky-conservative piano nerds, nerds who would be looking for flaws, would be paying attention to this sort of thing.
It leads me to wonder why the ambient reactivity was so strong, given the stability of the carbon fiber, lack of humidity driven migrating bridge pins, etc.
Perhaps Larry or someone with a more intimate day-to-day relationship to this creature could comment on its relative stability in normal and/or fluctuating ambient conditions.
Jim Ialeggio As a whole, I find the Steingraeber Phoenix to have more tuning stability. Tuning stability is always a collection of circumstances that must include how the piano was tuned and prepared. Additionally, material wise, the strings themselves are very sensitive to temperature. An air conditioner unit cycling, blowing cold air on a piano is killing any hope of tuning stability. The same goes for stage lighting. Anyone truly experienced in concert preparation know these things well. I have found the carbon fiber itself sensitive to temperature. I can not say that by itself, it is more or less sensitive than it's wood counterpart. That would require a proper scientific process that I have not done. I can say that, overall this Steingraeber Phoenix demonstrates a noticeable degree of tuning stability over it's wood counterpart.
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