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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>
<A title=erwinpiano@msn.com href="mailto:erwinpiano@msn.com">DALE =
ERWIN</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A =
title=pianotech@ptg.org
href="mailto:pianotech@ptg.org">pianotech</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> November 18, 2001 7:19 =
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Reverse crown was =
agraffe
bridges</DIV>
<DIV><BR></DIV>
<DIV> And you know the agraffes all the way to the top =
were not a
detriment but I believe now that they contributed to the sustain of =
the piano
by not bleeding energy away from the speaking length like =
modern FRONT
duplexes do. And hey Ron N. no rear duplexes and if memory serves =
adequately
long back scale. I really learned something as to why the stwy =
piano was
sooo popular even from the get go. This one was 1873.</DIV>
<DIV> </DIV></BLOCKQUOTE>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 size=3>All =
pianos have both
front and rear duplexes. The question is how long they are, what the =
string
deflection angle is (at the front), and whether or not they are =
tuned.
</FONT></DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 size=3>The =
debate over the
full agraffe design vs the capo tastro design centers around the =
effective mass
seen at the front string termination point. In theory, a greater amount =
of mass
seen at this point will improve the efficiency of the speaking length
termination. In practice, however, things aren't quite so clear-cut.
</FONT></DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 size=3>The =
agraffe system
obviously presents a lower mass termination point than does the capo =
tastro bar
system. This is especially true if the capo tastro is mass coupled to =
the
pinblock flange as it is with the traditional Sohmer designs and with =
the
current Baldwin SF-10 and SD-10 designs. So, in theory the larger mass =
of the
capo tastro system should be clearly superior. That this superiority is =
not seen
in practice should lead us to look at the other factors that affect =
sustain to a
much greater extent. </FONT></DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 size=3>As =
long as we don't
deliberately bleed energy away from the speaking length of the string =
(as is the
case with the tuned front duplex, or aliquot, designs), sustain depends =
more on
the potential energy storage capability of the speaking length of the =
string and
the design of the soundboard assembly than on the amount of mass seen at =
the
front termination point. </FONT></DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 size=3>Last =
Friday and
Saturday evenings I attended performances in 'The Strad Room' (a small =
recital
room seating 50 to 65 people). The piano in this room is a six-foot 1910 =
Geo.
Steck in which I have installed a considerably redesigned soundboard and =
bridge
system. (It also has vertical hitches and a nice, long backscale with no =
attempt
being made to tune their lengths to anything.) This piano uses =
agraffes
though the treble section -- in this case, C-88. I was impressed =
again (as
were the musicians) with the wonderful tone dynamics and sustain of this =
piano.
At least up to about A-85. The deficiencies of the agraffe really become =
apparent in the last three or four notes of this piano. Judged by =
themselves
they are not so bad, it's just that, compared with the performance up to =
that
point they do fall off considerably. (This piano does not use overhung =
agraffes,
which would have helped considerably. The last few notes have a strike =
point
problem.)</FONT></DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Lucida Sans" color=#000080
size=3>Del</FONT></DIV></BODY></HTML>