>That's not a qualified explanation Ron. You simply are making an unsupported >declaration. On what basis do you conclude that any sound heard in this >hypothetical situation is from the string vibrating the rest of the system in a >transverse fashion and not because of compression waves transferred through the >bridge ? Especially in light of the experiment McFerrin describes which quite >clearly validifies that compression waves can and do indeed cause sound to >emanate >from the sound board in this fashion. Does he? You quoted: >"The transverse wave of the string sets up a longitudinal wave through the >thickness >of the bridge so the energy reaches the sound board." > >And these in a book that, though titled "The Piano -- Its acoustics" has no >chapter >expressly dedicated to sound board mechanics. And where exactly does he say that these waves cause sound to emanate from the board in this fashion? Everyone and their Aunt Sally agrees that every kind of wave known to man travels in just about every part of a piano. The question is whether the wave causes the soundboard to move, isn't it? >And by your own logic Ron... some >influence.... no matter how small... is significant, though you seem say >that if >its some then it must be all. Not exactly. I'm saying that string/bridge movement is the primary driver. I've been fighting this all or nothing, black and white thing through this whole thread. The strings moving the bridge and soundboard do not exclude compression waves or anything else. It just defines the primary mechanism. That has been, and is my claim. What I write, and what you feel I must have meant are very often considerably different things. And yes, the forces involved, and the resulting movements are very small. If I jump into the air, I'm not only pushing myself away from the earth, I'm pushing the earth away from me too - action/reaction. There's no way you'll ever measure the reaction in this case, but physics tells us the reaction does happen. The reactions we're talking about here in pianos are on a considerably grander scale since the mass differences are somewhat closer, so they by extension must also happen. It's not like not making the minimum height limit on a Disneyland ride, the effect doesn't cease to exist and go away if it isn't big enough to suit you. So how could a compression wave traveling through the bridge possibly move the soundboard, and what's the physics behind it? >So was the ripple, but I will finish re-reading all this in the next couple >days >and look out for your clothesline analogy. Once again, the ripple is an effect, not a cause. >I am, perhaps due to my own >ignorance or perhaps due to some other attribute, a bit more open to pondering >differing ideas.... Funny how McFerrins statement about transfer of energy from >strings through the bridge is nearly, if not out and out, identical to Robins >though... I mean if this theory of his is so stupid and all.. Pondering different ideas is what I'm doing here too, and still not seeing anything to support this one. I'm quite willing to be shown to be wrong and to be educated. I eagerly await the key revelation that makes this all work, if there is one. And I would greatly appreciate it if you wouldn't put words like "stupid" in my mouth. When I think you are qualified to translate for me, I'll send you a request for services and a check. Meanwhile, please stick to reasonably accurate quotes and I'll do my own thinking. Ron N
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