Re: Bøsendorfers, was : Buttressed Arch. Question for Ron N. - increasing rim density

[A440A at aol.com]

Ric writes:

<< Another question comes to mind since you site more power.... Power is 

the tradeoff for sustain when talking about impedance issues in 

pianos... yes ? << 

    I don't know if that is actually a fact.  Resonant systems often 
demonstrate an increase in both when the system becomes more efficient.  
     Consider what we could expect from rims made of rubber,  which would be 
dead everywhere, I think, to a rim made of glass, which would probably be 
pretty loud over a small range of notes.  Somewhere in between is a material that 
possesses the optimum density and elasticity to maximize the energy's 
transformation from mechanical to acoustic.   
     The weight of the framing and case, the thickness of the plate, the 
thickness of the board, the bearing pressure, back-scale length, etc. all combine 
to create what is basically a wooden drum. We want it to be evenly responsive 
to all frequencies from 27.5 Hz to over 10K.   A rim-builder I am not, but all 
other things being equal, I would expect to see a softer rim material absorb 
more energy than a denser one.  I don't know that a soft wood rim with large 
inserts of metal, or whatnot added is going to respond the same way as an 
uninterupted laminate of a denser wood.  
    I say that while keeping in mind an anecdote about Andre Segovia.  He, in 
order to prove a point about the guitar's top being the major component of 
the sound, had a guitar built with paper mache sides.  It sounded great.   

>>So if we can claim more power AND more sustain because 

of the rim conditions, then a good explanation as to how this works is 

in order me thinks. >>

Well, Ric,  over here, we have a long tradition of devices for this.  
        We have gas additives that give more power AND better gas milage.  I 
don't know why people don't just fill the tank up with this stuff straight and 
never stop, again. 
We got light bulbs that use less energy AND give more light, (though 
everything has a sorta bluish tint to it). 
We got lawn stuff that kills weeds AND fertilizes the grass, (though 
sometimes you get a totally brown lawn, and other times you end up fighting the weeds 
for your life on the way to the mailbox). 

    This being the age of more and MORE,  more power AND sustain is all we  
accept, so I think that is why maple has been the choice for so long.  We got 
plenty of other kinds of wood, and  a lot of it is easier to work with, but a 
musical response that comes from laminated maple has been recognized, and we 
still pursue this particular combination of elasticity, strength, and musical 
liveliness.  
    
Regards, 
Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html