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<DIV><FONT face=Arial size=2>This is a pretty good explanation of what I am
calling increased vibrability.</FONT></DIV>
<DIV><FONT face=Arial size=2>Chris Solliday</FONT> </DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=andrew@andersonmusic.com
href="mailto:andrew@andersonmusic.com">Andrew Anderson</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=caut@ptg.org
href="mailto:caut@ptg.org">College and University Technicians</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, May 21, 2007 8:02 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [CAUT] killer octave
resonator</DIV>
<DIV><BR></DIV>Ric,<BR>I've been thinking about doing this to a late 90s D
that is going weak in that range. I'm inclined to think along lines of a
soft assembly that is soaking up vibrational energy (the thin weak materialled
belly rail). I suppose stiffening this up might resist crown collapse a
little but there is so little change in length, as others have pointed out,
that this idea is questionable. My theory leans towards stiffening the
soundboard terminations against energy loss results in more of the energy
being expended in vibrating the soundboard then in the
belly-rail.<BR><BR>Andrew Anderson<BR><BR>At 05:14 PM 5/21/2007, you
wrote:<BR>
<BLOCKQUOTE class=cite cite="" type="cite">Hi Chris<BR><BR>I am reasonably
comfortable with how it does what it is supposed to do.... at least I think
I am... I just dont see how it can substantially cure an already acute
killer octave situation... and I am not sure I see how it prevents one.
<BR><BR>The reason for this lack of understanding on my part is because I
have interpreted the <<killer octave syndrom>> to be equivalent
with a failure of the soundboard rib assembly to support downbearing at the
effected area. So it seems to me that a strong enough support directly
under the bridge at this area is what would be needed to prevent that.
I dont see how increasing the stiffness of the belly rail provides that.
<BR><BR>Misunderstand me not.... I am not saying anything along the lines of
<< I'm not a believer >>... I just wish someone would go into
detail to explain the relationship between a stiffer belly rail and how this
lessens the likelihood or degree of a case of killer octave syndrom.
<BR><BR>Perhaps my understanding of what a killer octave is to begin with
needs correcting..... ?<BR><BR>As I believe I am probably not alone in a bit
of head scratching here.... I think it would be benificial for those who
have some insights into this to expound a bit on the whole matter.... both
exactly what the killer octave really is, its causes etc etc etc... and how
a stiffer belly rail relates to it.<BR><BR>Thanks.<BR><BR>btw... I have one
of these devices... and just havent gotten so far as to installing it on an
appropriate instrument.<BR><BR>Cheers<BR>RicB<BR>
<DL><BR>
<DD>RicB,<BR>
<DD> I can't explain why the resonator works any more than I have.
Read Bob Grijalva's article in a recent PTG Journal or the instructions
that come with the device, from Pianotek. I will offer, however, that it
works PDG and if you try one one you will know that too, even if you never
fully explain it.<BR>
<DD>Perhaps a quote from the instructions by Bob G could help,<BR>
<DD> "The challenge in desgining the Treble Resonator was enabling a
connection between the rim and belly rail that did not interfere with the
vertical bolt that extends to the plate from the treble bell. As mentioned
earlier (in PTG article), this vertical bolt is the very reason why pianos
of this type do not have a wooden beam at that juncture, leaving a lengthy
section of the belly rail unsupported."<BR>
<DD>"I also wanted the adjustment to be mechanically intuitive. The Treble
Resonator works by pulling the rim and belly toward each other through
contraction of the trunbuckle, rather than expansion, as in the Falcone
jack design. One should rotate the tunbuckle in a clockwise manner in
relation to the plate that is attached to the belly rail. This contraction
works to reinforce and integrate the entire system, possibly providing
linkage betweeen the belly and the rim, enabling them to expand and
contract in tandem through seasonal changes, rather than going their own
separate ways."<BR>
<DD>Sorry for so little science,<BR>
<DD>Chris Solliday <BR></DD></DL></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>