Hi Fred I agree with very much of what you say below. Especially the point you make about the practical usefulness of using CA or Epoxy in bridge pin holes relative to helping reduce the occurrence and severity of single string beats. I remain unconvinced however that it has so directly very much to do with the pin being firmly rooted in the hole... if for no other reason then because I find so many many instances where a pin is very loose and there is no beat... and instances where a pin is tight as a whistle in a keyhole where there are beats. I agree also 500 % that crisp and precise terminations definitely are desirables relating to clean sound... tho to what degree these relate to the single string beat phenomenon is another question. Good point on the experiment I suggest. And I agree that increased side pressure would tend to counter any increase in flagpoling. That said, one of the main arguments for flagpoling as a source of single string beats is that the surface area of the bridge face (to about 1-0.5 mm deep) is not able to hold the pin tightly in the first place. There is already quite considerable side bearing pressure on the pin to hold the pin firmly pushed to the far side of the hole already as it were. I admit I havent any mechanics numbers on hand to back up the postulate... but I think holding the pin so loosely and so far up in the <<air>> as it were would indeed result in a net lessening in its ability to stay stiff in the face of string vibrations. In anycase, you can do the same experiment with vertical pins and find what amount to the same results. I did quite a bit of work with a vertical notched bridge pin solution a while back in developing an alternative to present day bridge agraffes and bridge / bridge pin terminations a while back. That actually that was one of the things that got me started off on all this single string beating thing. Cheers, and mucho appreciatos for the dialog so far to one and all. RicB On Apr 16, 2007, at 5:29 AM, RicB wrote: > There is so much micro movement going on between the bridge / > bridge pins / bridge interface with the soundboard that is on a > scale large enough to contribute directly to a single string beat > condition that it is actually quite surprising the loose pin > explanation got started in the first place... let alone gained so > much steam. Hi Ric, Interesting thoughts on the "false beat" phenomenon. As to why the loose pin explanation got started: when it is possible in many, many cases to clear up false beats by adding a "filler" material next to the pin, one begins to make assumptions <g>. I guess your contention is that in applying those materials (CA, epoxy) you are doing more to stiffen the termination area than to fill the gap. Could be. One way or another, it has a lot to do with the pin being firmly (relatively speaking) rooted. I think some high speed videography might yield real information on this issue, as opposed to the conjectures we mostly deal with. Taking a string that is producing a noticeable false beat, focusing close up on the bridge pin, seeing whether the pin itself moves, and whether there is a regular frequency that can be associated with the frequency of the false beat. In any event, from a practical standpoint CA and epoxy are good cures for much falseness. Crisp terminations (well shaped capo or machined/polished agraffes, new bridge pins without nicks and grooves, pins firmly held by the bridge, good notching) yield clean sound, in my experience. As to your experiment of placing a centerpin between string and bridge cap, I'm not sure it proves anything about loose bridge pins (maybe it says something about notching). By raising the string up the angled pin, you are greatly increasing the side pressure on that pin, hence "stiffening it against the side of its hole." You are also somewhat increasing the lever advantage of the string versus the pin, increasing that effect (of pushing it firmly against the far side of the hole). So I think, contrary to your reasoning, that you are reducing the likelihood of flagpoling. Regards, Fred Sturm University of New Mexico fssturm at unm.edu --
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