Article about bridge agraffes - function, types

[RicB]

Calin

You repeat a few statement of facts here.  If they are facts then you 
should have no trouble showing some reference material to back up these 
statements... And I for one would be very interested in the most 
positive sense to read them. Please see below.


     > 2nd you declare that the larger footprint of the agraffe on  the
    wood of  the bridge itself will cause the rest of the assembly to
    vibrate more  because > he string will not be able to dig into the
    wood as  it vibrates.  This also needs documentation.   A couple of
    points on  this... I would   think this claim > were were true... it
    would be true for all  frequencies

    It is not true for all frequencies. I stated repeatedly that a
    string bearing against a wood cap/pin and digging into it mostly the
    highest frequencies. As you go down the scale the effect decreases,
    to the point of becoming probably negligible.

You state the above as fact.  Is it ?  Where can I read about this ?


     > and you would be able to measure a significant output increase
    across  the board.  I would also point out that the string is
    terminated at

    The significant output increase is in the top treble, not across the
    whole scale.

Same thing... have you measurements or documentation to support this.  
Or is this conjecture ?


     > least as much by the pin itself, which while not having as big a 
    footprint in the wood of the bridge as an agraffe... certainly is
    far  harder then wood.  Then there is the matter of what degree  the
    presumed  lessened "efficiency" of the bridge/pin assembly becomes
    significant  enough to make a measureable difference in this context.

    The pin is harder, but the wood which touches the string acts like a
    damper for very high frequencies. I exaggerate this to make my
    point, but that's
    what happens. Piano makers have long used the hardest woods in the
    top treble caps. I believe they recognized the need for a very stiff
    material there, to minimize energy loss. The bridge agraffe is
    another quite efficient) way of reducing energy losses where it
    matters most.

Again... I know of no information anywhere that says piano manufacturers 
were primarilly interested in anything else then durability  Surely if 
they were concerned about energy loss there would be something written 
in one or another patent down the line.  And I dont know of any data 
that shows the lossyness of the standard bridge / pin  configuration is  
*significant*  enough compared with agraffes to support  your 
conclusion.  How can/could I possibly without any data/doc/etc to go on ?


     > 3rd... which moves on a bit... you couple the above two to   the
    increase  in sustain seen in some agraffe pianos... presumably
    looking  away from >the added mass of the brass and other design
    issues that  accompany such  instruments that we already know
    significantly contribute to  sustain.  I  >dont think you can do
    this without further ado without  qualifying this  as conjecture.


    I'm not saying mass doesn't influence tone. It does. But I'm saying
    that mass alone, while it can help, is not sufficient to get the
    most of the piano's treble if you keep a traditional bridge cap/pin.
    A bridge agraffe helps by wasting less energy. Using a bridge
    agraffe doesn't mean one shouldn't take their weight into account or
    use supplemental weights to adjust the soundboard's response to the
    string scale's energy input.

Yes, I understand what you are saying.  I just dont see that you are 
doing anything more then making at best an educated guess as to what 
*might* be happening.


     >  Without supporting documentation, none of this can be
    substantiated,  and... if in the end it turns out you actually can
    not defend these  claims thus... > you will end up in a rather
    uncomfortable position I  would think.


    I am actually very comfortable in my position. I don't see a
    conflict or a need to defend myself and I hope others will be
    encouraged by my article to
    do further research on bridge agraffes, string terminations, mass
    loading etc.  I'm not attacking any theories, just presenting my
    opinion on a device which I believe can help piano builders make a
    better piano.

    Calin Tantareanu

Calin... you asked for commentary.  Thats what I am offering.  As I read 
your paper it presents all this as if this were all factual.  I do not 
see at all that your paper is clearly supposition in nature.  So... 
thats my commentary... If you present something as fact... then you have 
to back it up with references to these facts.  If you dont have those.. 
then you should present it as supposition instead.  The potential 
uncomfortable situation is when you present something as fact, without 
backing it up... and end up wrong :)

Just trying to help here... nothing else. 

Cheers
RicB

    http://calin.haos.ro