[pianotech] YC Capo Bars

[William Truitt]

I have heard the glue line argument from others against the use of
horizontally laminated bridge caps because of the barrier of the glue line.
I'm not equipped with the knowledge or scientific tools to advance the
argument on either side.  But I would follow up what Del said where in
testing they couldn't hear the difference between the three kinds of caps by
saying that - if the glue lines do indeed interrupt or distort the movement
of the vibratory energy, such changes to the patterns of movement are
insignificantly small at best and inaudible (if we are to believe Del and
Baldwin's testing).   As such, the most we can say about this glue line
argument is that it is no more than trivially true and therefore of no
practical consideration  in the real making of piano bridges.   And other
considerations such as consistency and tuning stability can reasonably be
held to be far more important if one is choosing between a horizontal cap or
other methods.  

We regularly hear people asserting that they can hear the influence of
certain materials or particular aspects of a design in a piano.  I think it
is true that for some things that  we can. (say the effects of excessive
downbearing for example).  But it is also true that it is damn difficult to
isolate the effect of a particular element from everything else that is
influencing the tone, and there's the rub.


Will



-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Delacour
Sent: Tuesday, September 21, 2010 3:45 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] YC Capo Bars

At 22:48 -0500 20/9/10, Ron Nossaman wrote:

>...The string moves the bridge, and the bridge moves the soundboard, 
>which moves all the strings, etc. The less one dwells on presumed 
>mystical vibrational energy waves, the closer one gets to observed 
>and measurable results...

On your side you have the Flat Earth Society and maybe the Pope; on 
the other the whole body of scientific literature concerning 
mechanical elasticity and acoustics.

JD