Bridge Seating (was Re: Where to notch a bridge, & relative effects ????? (Advice sought)

[Ric Brekne]

Hi

I thought for those of you who were interested the following link might 
be instructive. 
http://www.pianostemmer.no/brekne/referhtml/stringseating.html  . After 
reading the short article, take a closer gander at figures 3,4 and 5.

Figure 5 depicts the (only) situation that renders string seating 
basically useless. Figures 3 and 4 show where string seating will be 
appropriate and useful.  As to the whether or not it is possible for the 
situations in figure 3 and 4 to occur let me just say this.  I can 
understand why some can have difficulty in accepting these as possible. 
Especially figure 4 is difficult to accept. It seems so counter 
intuitive. Pin angles, friction moments, and down bearing  all would 
seem to conspire to prohibit this condition.  Yet it is a fact that it 
can and does occur.  As for figure 3... there really should be no doubt 
as to the possibility of this occurring.  Aggressive string seating out 
on the speaking length will nearly immediately cause this condition to 
some degree or another. The roll off of the string groove can be steep 
enough for the strings to unseat at the pin. Yet the entire surface of 
the bridge  (including the notch edge) is still above the line of 
deflection.  String seating in this case should be directed at smoothing 
out the string indentation so that it more closely parallels the line of 
deflection. This is  IMHO why it is important to seat behind the bridge 
pin on the bridge surface itself.

The valid point that string seating opponents have in all this is 
centered around the condition in figure 5.  There is no way any string 
seating will result in a lasting fix. The concern is more then justified 
as it is actually quite easy to cause this condition with many of the 
string seating procedures being used by techs.  However it is also easy 
enough to avoid creating the condition if one careful and mindful about 
string seating. 

String seating is not IMHO a tool to get rid of false beats.  It 
addresses other types of falseness and unclarity.  False beats (that 
self-beating string that reacts to sideways pressure by a screwdriver) 
and their elimination are a different subject matter entirely me thinks.

Cheers
RicB