<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=US-ASCII">
<META content="MSHTML 6.00.2900.2802" name=GENERATOR></HEAD>
<BODY id=role_body style="FONT-SIZE: 10pt; COLOR: #000000; FONT-FAMILY: Arial"
bottomMargin=7 leftMargin=7 topMargin=7 rightMargin=7><FONT id=role_document
face=Arial color=#000000 size=2>
<DIV><FONT size=3> Ron---David</FONT></DIV>
<DIV><FONT size=3> Good discussion. I've been
lurking in between sessions with the </FONT></DIV>
<DIV><FONT size=3> Rah-chestah project.</FONT></DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size=2>
<FONT size=3><STRONG>Ron N wrote</STRONG></FONT><BR>> One question I have
is why, if you want to create a higher design loaded<BR>> board, do you
need to increase the bearing? On an RC&S board, with little<BR>>
change in tone coming from modest changes in bearing, isn't it enough
to<BR>> simply stiffen the assembly with the same residual bearing?
<U>The difference<BR>> would be, I assume, the amount of deflection.
But if the panel deflects 30%<BR>> instead of 50% is that a problem
tonally? Wouldn't you have the same net<BR>> tonal effect without
having to increase the actual bearing load on the<BR></U>> board?
</FONT></BLOCKQUOTE>
<DIV> <FONT size=3> </FONT><STRONG><FONT size=3>My question is how
does that relate to the sweet spot I believe exists for crown
compression, bearing & tone in a belly system. Being that the
system is a spring, the question for all Soundboard designers?redesigner is how
stiff is stiff enough for the type of tone desired & it's subsequent life
span.</FONT> </STRONG></DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size=2><BR>It
might. Design load isn't my concept, and isn't where I <BR>start with design.
My intent isn't to accommodate a higher or <BR>lower design load, but to
provide adequate bearing that, if <BR>the board sinks out somewhat over the
years, there will still <BR>be adequate bearing <U>left. Same with crown, to
maintain the <BR>opposing spring system of string and soundboard even with
some <BR>long term settling. I'd like to think that as well as sounding
<BR>good to me now, they won't end up with a zero bearing negative <BR>crown
killer octave some day, and will sound good to me for a <BR>very long
time.</U></FONT></BLOCKQUOTE>
<DIV> <STRONG><FONT size=3>Oh well said. This is every bodies
dilemma but I am comforted by the fact that we have the history of 150 years or
more of data to judge how well the compression crowned board have held
up.......or not. In some climates they've held up very well structurally &
where they have tonally as well. </FONT></STRONG></DIV>
<DIV><STRONG><FONT size=3> That being said none of us( I
think none) are using straight sugar pine ribs with a MOE
less than Spruce. SO we know that track record. SO now enter boards
which are rib crowned spruce with higher beam strength especially
with a tight grained spruce, laminated rib structure or Over I beam & we are
concerned that the crown, bearing & tone won't hold up? Ron have
faith</FONT> <FONT size=3>man. They will hold up.</FONT></STRONG></DIV>
<DIV><STRONG><FONT size=3> There is also a larger issue that we have been
tip toeing around & so I will say it. The tonal envelope on many of these
boards to my ears and others is a new & uniquely wonderful sound and
may be judged superior by many to many compression crowned
systems. </FONT></STRONG></DIV>
<DIV><STRONG><FONT size=3> (I have noted the tonal clarity by simply
switching to all spruce ribs.)</FONT></STRONG></DIV>
<DIV><STRONG><FONT size=3> Hopefully the tone crown &
bearing will prove to having superior longevity as
well</FONT></STRONG></DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size=2>Time
will eventually tell, one way or another, <BR>but that's one of the factors
I<U> consider. This stuff is still <BR>relatively new to me, and I don't
pretend to know the details <BR>of all possible combinations, which is why I
continue to <BR>explore and learn. In five years, I may still be loading them
<BR>like this, or I may not, depending on what I've learned in the</U>
</FONT></BLOCKQUOTE>
<DIV> <STRONG> <FONT size=3>An honest man. We are all on that
learning curve</FONT></STRONG></DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000
size=2><BR>interim.<BR><BR>Part of the equation in determining all this is
beam <BR>clearance, which puts limits on rib depth, crown radius, and
<BR>loading. You pick your set of ranges for variables, juggle as <BR>you
think will take you farther in the direction you want to <BR>go, and prove or
disprove the hypothesis by stringing the <BR>sucker up and hearing how you
did. I'd love it if someone <BR>threw large quantities of money at me to
explore this stuff <BR>systematically in much greater detail at higher speed,
but I'm <BR>a one man shop with a tuning clientele, with the need to make
<BR>a living in there somewhere. Otherwise, I'd be fearless. I <BR>hate it
when necessity interferes with fun, ya know?</FONT></BLOCKQUOTE>
<DIV><FONT size=3><STRONG> You empericalist. Great self
effacing post!!!!!</STRONG></FONT></DIV>
<DIV><STRONG><FONT size=3> Dale</FONT></STRONG></DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000
size=2><BR><BR>Bummer.<BR><BR>Ron N</FONT></BLOCKQUOTE>
<DIV></DIV>
<DIV> </DIV></FONT></BODY></HTML>