> > Because when it doesn't, it eventually leads to tone production problems > > and false beats when the pin gets loose in the bridge. It's a practical > > consideration rather than a theoretical one. > > >Ron, does this mean that you believe that if the pin is not loose in the >bridge, >positive downbearing in the front and contact of the string at the front >edge of >the bridge cap don't matter? > >Ed Sutton If the pin angle and row offset is sufficient to supply adequate friction at the bridge pin, the notch edge can be back into the bridge away from the pin bisection without causing tone problems or false beats - until the pin gets loose and starts to flag pole. Go around and look at the bridge notching on the new pianos in the exhibition hall at Nashville. You will find some that are very intentionally and very uniformly notched "too deep", yet don't seem to have all the false beats that we were all taught HAVE to be there because of the different speaking lengths for the same string. This doesn't mean that front bearing and coincidence of the notch edge with the pin doesn't matter, it just means that under certain very specific circumstances it doesn't cause obvious tonal problems. I think it's a built in problem waiting to happen. Personally, I'll stick with positive front (and overall) bearing, adequate pin angle and row offset, and a notch edge that is at, or a hair behind the center of the pin as my standard. The more redundant the built in safety features, the better the chances of avoiding early failures. This is a chronic over-builder speaking. When I learn of better ways to get the performance AND dependability I want, I'll adopt them. This doesn't relate directly to your post, but I thought it was time to say it again, to try and keep all these details in perspective. What we work with in the field is full spectrum, from near ideal to nothing being anywhere near ideal. We have to work with what we have in front of us, warts and all. The angles are already there, the pins are already loose, and the termination is very often already too far gone for us to do much about with a tuning service call. I haven't seated a string with anything more than a fingernail for a long time. If that won't help it, whacking it with a hammer won't either. Mostly, I don't bother because most of the treble is noisy, but I'll sometimes try to make the ones that stand out as real screamers a little less bad. Yes, seating seems to help in the short term, but I don't consider that justification for doing it with any more gusto than can be generated by a fingernail, since the loose pin is nearly always the mechanism that generates the beats (allowed by the front bridge termination damage already present), seating the string doesn't fix anything. In my opinion, if the whole treble, or a significant part of it, "needs" seated to be acceptable for tuning, the piano is due for some serious work. Driving the pin has a better chance of being of some long term benefit, except for the damage done to the notch edge by the string as it goes down with the pin. Mostly, the immediate improvement heard is because the string has been seated in the process. If the pin isn't bottomed in the hole, and so isn't pushed back up where it was in the next dry cycle, getting the string out of the bottom of the worn groove in the pin as David Love described, there will probably be some long term benefit. Ideally, turning the pin to present a fresh surface to the string would be both less destructive to the bridge top, and probably at least as likely to help. Of course, you'll snaggle up the top of the pin doing it with pliers, but life is full of little trade-offs. I've played with this some in the shop before tear down when snaggled pins didn't count, and it seems to work at least as well as driving pins, and better than seating. For what it's worth. My intention in all this is to try to understand what we are really working with, and what we are really doing when we think we are doing something else entirely. Ron N
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