Bridge pin angles

[Ron Nossaman]

>> As I've said before, I don't see a need for it, nor do I consider a 
>> poorly functioning soundboard to be "fixed" by it's application.
> 
> 
> Why assume the presence of a poorly functioning soundboard?  Or that I 
> or Wapin is proposed as a "fix" for such?  

Since we started hearing about Wapin, it was encouraged as a 
retrofit for poor sustain, killer octave problems, and such. If the 
problem isn't the soundboard, can the Wapin installation affect 
hammer voicing, duplex tuning, string leveling, downbearing, or any 
of the other reasons, suspected or otherwise, for tone problems? If 
the piano sounds good, with good sustain, what would entice someone 
to modify it's bridge pin configuration?


>There may very well be no 
> "need" for it.  That doesn't preclude the fact that someone claims to 
> have observed and measured certain phenomena, and created an experiment, 
> albeit in the form of a commercial enterprise, which claims to interact 
> favorably and predictably with said phenomena.  The claims may or may 
> not be accurate, but it seems a bit capricious to dismiss the ideas out 
> of hand, given their applicability to the topic we're discussing.

Just because I didn't include ten thousand words of history, 
analysis, and argument to be picked apart microscopically and tested 
for unvoiced presumptions of intent for the next week doesn't mean 
my opinion is capricious. Nor did I deny that someone claims to have 
observed and measured certain phenomena, whatever that means. I 
voiced an opinion. You don't have to agree with it, or even 
understand it, and are welcome to install the Wapin system in any 
piano you care to and legally may. I have no problem with that.


>> I disagree. I consider these concerns to be inseparable. Trade-offs 
>> can't be reasonably assessed without considering function, production 
>> cost, and longevity.
> 
> 
> Maybe I mis-spoke, though our history suggests that my explanation will 
> likely kalso fall short.  I was trying to suggest that it might be 
> instructional to contemplate as clearly as possible the idealized, or 
> theoretical physical mechanisms operating, which could be subsequently 
> compared to the "real-world" issues of materials, unpredictable 
> production, etc. Separate, then synthesize.  In rereading Phil's 
> original post, I realized that I imposed a bit of my own bias in focus 
> of my comments.  Phil actually was contemplating both the practical AND 
> the more theoretical. 

As am/have I.

> First of all, in the course of most of the recent discussions, I and 
> others have attempted to establish that the classic "false beat" is not 
> the only acoustic phenomena that is observed as a termination anomaly.   
> However, in the quote above, I was trying to pose the question whether, 
> in purely mechanical / acoustical terms, an angled bridge pin elicits a 
> different response than a straight pin.  Surly there is some merit in 
> asking such a question, especially if the answer turns out to be 
> affirmative. 

You've asked this before, from various directions. Perhaps someone 
else knows the answers to how any given construction detail relates 
directly to tone production. Sorry, but I do not. I am hoping to see 
this stay somewhere in the vicinity of the subject until most of the 
points have been explored. Perhaps we can nail it down this time and 
not have to keep going through it from the beginning every year.


> We can't assume downbearing, and we can't assume front bearing, whether 
> caused by wood crushing, poor planing, incorrect setting of bearing, 
> etc.  You say "we angle and offset pins to provide a positive 
> termination that's largely independent of bearing".  What, precisely,/ 
> IS /"positive termination"?  

What "precisely" is tuning?


>Does it mean that the reflection of waves 
> in all three axis (pl?) occurs at a point which is a singular distance 
> from the opposite string termination? Does it imply a certain ratio of 
> reflected energy to absorbed energy? Does it reference the actual space 
> and surface area that constitutes the termination?  And of course, does 
> it define or quantify the degree of sliding motion of the string along 
> the terminating structure (bridge surface or bridge pin) parallel to the 
> direction of the wave, thus a lateral movement along the bridge edge, or 
> a vertical movement on the pin?

I'd call positive termination containment. If the string can go 
through it's contortions without relative movement between the 
string and bridge, I'd say it's positively terminated. A string that 
can slide transversely, or lose contact with the bridge isn't.