Hi Paul, >Perhaps it would be better to say that when energy is imparted to the >string, the distribution of torque will not remain static (vs. "evenly >distributed"). * I knew what you meant, I just don't see any reason why that would be the case. >I was thinking more of the V bar with its single horizontal contact >point than of the bridge with two (pin and cap) or the agraffe with a >partial wraparound contact area. (Of course the string creates a small >groove in the bar, but I think it still allows for more torsional >movement than at the other two types of bearings. Once started, any >torsional wave travels longitudinally because it releases torque at one >end of the string as it builds at the other, which then needs to be >released in the opposite direction. * My thinking was that the type of termination shouldn't make any difference. It's the bearing angle across the v-bar, bridge pin, or agraffe that I was considering. The two legs of the formed angle act like outriggers to prevent torsional movement at the bearing point. I agree that a torsional wave, once started, would probably affect the longitudinal mode. I just don't see how it's going to start at the bearing points under these circumstances. >Actually, I was thinking just the opposite - that the energy imparted by >the hammer will cause the string to try to straighten itself at the >strike point, sending a change in torque towards both ends of the >string. Just like transverse waves, but in a rotational direction. * I don't understand why this would impart any torque. Why would a string try to "straighten" itself (I assume you mean "untwist" here) where a hammer hits it? I suspect that the overall torque would increase with an increase in string tension, but I see no reason for a localized change in torque from a hammer impact. Please explain. >Not much to go on, really, just instances of replacing strings that I >know had some torque because I installed them that way, or showed >torsional movement when broken or cut. May have been some other factor >that caused the beats to go away. > >Paul * Aye, there's the rub! There are too many unknown variables in a field situation to blame the string twist for false beats. No one that I know of seems to have done any controlled experimentation that indicates that twisted strings (within reason) sound any different than straight. In fact, the only experimentation I'm aware of indicated that there was no discernable difference. We've all heard it said by nearly everyone, lo these many years, but if it's that critical, it ought to be pretty easily demonstrated, shouldn't it? If it was, I bet we'd have seen an Institute or Seminar class (or six) proving it by now. If it's common knowledge, why haven't I seen any indication that it's true? I wonder how one would go about measuring longitudinal partials anyway. Can this be done with an ETD? If so, someone could set it up fairly easily and whack the bejeebers out of a string to get a first hand look at what happens to the pitch of the longitudinal. Where are our instrumented experimenters out there? Ron
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