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<DIV>Got it, thanks.</DIV>
<DIV> </DIV>
<DIV>P</DIV>
<DIV> </DIV>
<DIV>
<DIV>In a message dated 3/16/2011 1:11:13 A.M. Central Daylight Time,
del@fandrichpiano.com writes:</DIV>
<BLOCKQUOTE
style="BORDER-LEFT: blue 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 size=2 face=Arial>
<DIV class=WordSection1>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: navy; FONT-SIZE: 11pt">My tests
demonstrated that when the tuned front duplex system is working as advertised
sustain rate increases and sustain time decreases. Think of it in terms of
conservation of energy.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: navy; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: navy; FONT-SIZE: 11pt">ddf<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: navy; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Delwin D
Fandrich</SPAN><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt"><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Piano
Design & Fabrication</SPAN><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt"><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt">6939
Foothill Court SW, </SPAN><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Olympia,
Washington 98512 USA<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Phone
360.736.7563 — Cell 360.388.6525</SPAN><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt"><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt"><A
title="mailto:del@fandrichpiano.com "
href="mailto:del@fandrichpiano.com%20">del@fandrichpiano.com </A></SPAN><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">—
</SPAN><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt"><A
title=mailto:ddfandrich@gmail.com
href="mailto:ddfandrich@gmail.com">ddfandrich@gmail.com</A></SPAN><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: navy; FONT-SIZE: 11pt"><o:p></o:p></SPAN></P></DIV>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: navy; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<DIV>
<DIV
style="BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; PADDING-RIGHT: 0cm; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt">
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><B><SPAN
style="FONT-FAMILY: 'Tahoma','sans-serif'; FONT-SIZE: 10pt">From:</SPAN></B><SPAN
style="FONT-FAMILY: 'Tahoma','sans-serif'; FONT-SIZE: 10pt">
pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] <B>On Behalf Of
</B>PAULREVENKOJONES@aol.com<BR><B>Sent:</B> Tuesday, March 15, 2011 10:46
PM<BR><B>To:</B> pianotech@ptg.org<BR><B>Subject:</B> Re: [pianotech] Tuning
the duplex sections<o:p></o:p></SPAN></P></DIV></DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><o:p> </o:p></P>
<DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt">Del:<o:p></o:p></SPAN></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt"> <o:p></o:p></SPAN></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt">I
just wanted to thank you for your articulate and concise statement. My
understanding has always been that the open front counterbearing increased the
sustain in the speaking length because of the transfer of energy back and
forth across the capo. Am I reading you correctly?<o:p></o:p></SPAN></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt"> <o:p></o:p></SPAN></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt">Paul <o:p></o:p></SPAN></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt"> <o:p></o:p></SPAN></P></DIV>
<DIV>
<DIV>
<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt">In a
message dated 3/15/2011 11:50:34 P.M. Central Daylight Time, <A
title=mailto:del@fandrichpiano.com
href="mailto:del@fandrichpiano.com">del@fandrichpiano.com</A>
writes:<o:p></o:p></SPAN></P></DIV>
<BLOCKQUOTE
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<P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt">1)
With an inefficient termination--i.e., a V-bar with shallow string
termination angles and "tuned" front duplex string segments on the other
side--energy can be transferred back and forth across the V-bar. Because the
duplex string segments are tuned (in theory, at least) to some calculated
partials of the speaking lengths, vibrating energy at or around the resonant
frequencies of the duplex string segments will pass back and forth across
the V-bar with relative ease. Among other things, this has the effect of
increasing the rate of decay in the desired speaking lengths because some of
the energy that is transferred across the V-bar to the duplex string
segments is absorbed into the plate at the front bearing bar. This loss is
in addition to whatever amount of energy is absorbed into the plate at the
V-bar.<BR><BR>Since the so-called "tuned" duplexes are rarely, if ever,
accurately tuned, these vibrating portions of string can, and often do,
produce sounds at undesirable pitches that are close to, but not quite on,
some harmonic of the normally speaking strings. As well, because the string
deflection angles are shallow and vibrating energy is being transferred back
and forth across the V-bar, any slight imperfections in the shape or surface
texture of the V-bar can, and often do, create undesirable vibrations or
"string noises." In an effort to control both dissonant vibrations and the
string noises it is a common practice to mute the front duplexes. This
damping absorbs some of the vibrating energy in the duplex string segments
but it does not stop the transfer of vibrating energy coming from the
desired speaking lengths of the strings to the duplex string segment. That
transfer continues but it's now a one-way street; energy is being dampened
on the duplex side of the V-bar and is now unavailable for any transfer back
into the speaking side of the V-bar so the decay rate in the speaking string
increases even more and the sustain time further decreases.<BR><BR>2)
When the string angles are greater than about 15˚ to 18˚ and the duplex
string segments are kept reasonably short energy is not freely transferred
back and forth across the V-bar between the speaking string segments and the
duplex string segments. The termination of the speaking strings at the V-bar
is more efficient and most of the energy arriving at the V-bar is blocked
and reflected back into the speaking string segments. Some energy, to be
sure, is still absorbed into the V-bar and/or capo tastro bar but very
little makes past the V-bar it into the duplex string segments. In this case
damping the duplex string segments makes little difference because there is
little energy there to be damped. <BR><BR>As an added benefit, because the
strings are not "rocking" back and forth at the V-bar, its shape is
less critical and string noises are virtually unheard of. <BR><BR>3)
The back scale is a whole other issue. Energy is not being transferred from
the speaking strings across the bridge terminations and to the backscale
portion of the strings. The backscale is set in motion by the motion of the
bridge(s). Whether or not the backscale string segments are tuned does not
materially affect the vibrating energy in the speaking portion of the
strings or their decay rates and, hence, will have little, if any, effect on
how they vibrate or how long they vibrate. <BR><BR>Whether tuning the
backscale string segments has any positive effect on overall piano
performance is, for me, at least, an open question. I have yet to see it
conclusively demonstrated by even the most ardent supporters of the scheme.
Keeping an adequate backscale length is clearly important but deliberately
tuning the backscale to some partial lengths of the speaking strings has
long seemed an exercise in futility. Besides, given the broad spectrum of
fundamental waveforms and partials driving the bridge(s) at any given moment
(while the piano is being played) it would be well-nigh impossible to avoid
finding backscale lengths that are not "tuned" to some fundamental or some
partial of some note or other. <BR><BR>ddf<BR><BR>Delwin D Fandrich<BR>Piano
Design & Fabrication<BR>6939 Foothill Court SW, Olympia, Washington
98512 USA<BR>Phone 360.736.7563 — Cell 360.388.6525<BR><A
title=mailto:del@fandrichpiano.com
href="mailto:del@fandrichpiano.com">del@fandrichpiano.com</A> — <A
title=mailto:ddfandrich@gmail.com
href="mailto:ddfandrich@gmail.com">ddfandrich@gmail.com</A><BR><BR><BR>-----Original
Message-----<BR>From: pianotech-bounces@ptg.org
[mailto:pianotech-bounces@ptg.org] On Behalf Of David Love<BR>Sent: Tuesday,
March 15, 2011 4:10 PM<BR>To: pianotech@ptg.org<BR>Subject: Re: [pianotech]
Tuning the duplex sections<BR><BR>Yes, that's right of course, went too far
with that idea. <BR><BR>So then why exactly does muting the front
duplex kill the tone? Even a light muting in which the rocking motion
is presumably unimpeded. What does the front duplex contribute in that
case (when it's unmated) and how does it contribute. Similarly, why
does muting the front duplex in a piano with a very short duplex not kill
the tone nor does the tone suffer, seemingly, from having a very short front
duplex. <BR><BR>David Love<BR><A title=http://www.davidlovepianos.com/
href="http://www.davidlovepianos.com/">www.davidlovepianos.com</A></SPAN></P></BLOCKQUOTE></DIV></DIV></FONT></BLOCKQUOTE></DIV></FONT></BODY></HTML>