Seating/false beats

[Ron Nossaman]

Hi all,


Excellent points! Thank you. I did mention early in this thread that strings=
 wear grooves, flat spots, whatever, in bridge pins, and offered that as a=
 possible explanation for this effect. That was before it was pointed out=
 that the side bearing was probably a greater factor. At this point, I=
 wouldn't doubt that pin wear is a contributing factor to keeping strings up=
 pins, but probably not a primary. Pin wear, however could have an effect on=
 tone quality. It's been noted that most of the false beats attributable to=
 front bridge termination occur in octave 5 1/2 - 6. Could the fact that the=
 strings are shorter here, and that the width of the poor termination spot=
 on the pin=20is a greater percentage of the speaking length here account=
 for some of this? I'm leaning (sorry) toward the possibility that the=
 natural harmonic frequency of the flagpoling bridge pin meshes with the=
 harmonic structure of the strings better in this area than lower down. A=
 larger diameter pin, lower in the scale, would have a higher natural=
 frequency (being stiffer) while the string frequency is lower. You wouldn't=
 get a match lower down like you would (might) in 5 1/2 - 6. It might be=
 frequency coupled. What do you think?  =20


I have also begun to suspect that the grooves in bridge tops are nearly=
 inconsequential in this process. I see them as merely a result of the=
 bridge expanding and crushing wood. In another post, I asked if anyone taps=
 strings down at the back pin. If they don't, how else does the bridge get=
 string grooves all the way across the top unless it's the result of this=
 expansion and crush?=20

Wouldn't you know it. I went and changed the thread title and everyone came=
 back. Murphy, is that you?


Regards,   Ron Nossaman



>
>I find this discussion very interesting. One thing that was not mentioned
>though is the fact that the bridge pins are softer material than the
>strings. When I remove these I usually can see indentations (is that
>English?). They actually are grooved. No wonder string want to stay up
>there. Since all the force is usually applied upward, that groove will have
>a tendency to be above the bridge plane. IMHO, that might be why when
>rebuilding it is necessary to replace these pins. The notching will help
>too, but I'm not so sure the sanding of the bridge would make such an
>improvement.=20
>
>Marcel Carey, RPT
>
>
>
 Ron Nossaman