Article about bridge agraffes - function, types

[Calin Tantareanu]

Ric,

I think I have already explained to you that my article is based mostly on
my personal observations and deductions. I did discuss it with other people,
but I am not quoting any other research in the field because I haven't seen
any. The way I write might be percieved as authoritative, but I never
claimed it's anything else than my personal opinion.
So take it as my opinion and feel free to bring as many counterarguments as
you can find, I'm not saying my words are gospel, just assumptions. I hope I
have answered your concerns this way. I prefer to deal with arguments
relating to the subject rather than trying to explain my writing style. 

Calin Tantareanu
http://calin.haos.ro
--------------------



> -----Original Message-----
> From: pianotech-bounces at ptg.org 
> [mailto:pianotech-bounces at ptg.org] On Behalf Of RicB
> Sent: duminică, 19 noiembrie 2006 22:49
> To: pianotech at ptg.org
> Subject: Article about bridge agraffes - function, types
> 
> 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
>