<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD><TITLE>Re: Killer Octave Question</TITLE> <META content="text/html; charset=iso-8859-1" = http-equiv=Content-Type> <STYLE type=text/css>BLOCKQUOTE { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } DL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } UL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } OL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } LI { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } </STYLE> <META content="MSHTML 5.00.2919.6307" name=GENERATOR></HEAD> <BODY bgColor=#d8d0c8> <DIV> </DIV> <BLOCKQUOTE dir=ltr style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A href="mailto:oleg-i@wanadoo.fr" title=oleg-i@wanadoo.fr>Isaac = OLEG</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = href="mailto:pianotech@ptg.org" title=pianotech@ptg.org>Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, April 20, 2003 = 11:58 PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> RE: Killer Octave = Question</DIV> <DIV><BR></DIV> <DIV><SPAN class=242401306-21042003><FONT color=#0000ff = face=Arial size=2></FONT></SPAN> </DIV> <DIV><SPAN class=242401306-21042003><FONT color=#0000ff = face=Arial size=2>Building and installing crown compressed soundboards have = been told me as being far way more difficult than rib crowned ones, and I see no advertising about the method nowhere (and indeed most pianist should = not understand the difference). Seems unfair to me to talk as you do.</FONT></SPAN></DIV> <DIV><SPAN class=242401306-21042003><FONT color=#0000ff = face=Arial size=2></FONT></SPAN> </DIV></BLOCKQUOTE> <DIV><FONT size=2>I have bellied soundboards using both systems and = must disagree that compression-crowning is any more difficult than = rib-crowning. Both require equal control over moisture content. Both require equal = attention to detail. If anything, properly rib-crowning a soundboard assembly has a = couple of additional steps. One must figure out just how much crown radius to put = where and then carefully machine (or otherwise obtain) precisely that radius. = Rib crowning is inherently more consistent and controllable.</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <BLOCKQUOTE dir=ltr style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV><SPAN class=242401306-21042003><FONT color=#0000ff = face=Arial size=2>I have the impression too that everyone there is focusing on crown and durability, while not many are comparing  the response = characteristics of the methods. </FONT></SPAN></DIV></BLOCKQUOTE> <DIV><FONT size=2><SPAN class=242401306-21042003>It was the = degradation of tone quality over what I considered to be a very short period that caused me = to investigate other crowning methods. For a number of years during the = 1970s and early 1980s I serviced new pianos using the compression-crowning = technique exclusively. While some of these instruments did indeed sound quite = marvelous, too many others did not. I did not keep track of percentages, but I'd = say from memory that probably two-thirds to three-fourths of them were marginal = as they came from the factory. Generally through the upper half to one-third of = the scale. Sustain would be short and the tone would be percussive. Even = back then this company was using a considerable amount of shaping and hardening in = their hammers to mask this tonal drop-off. It wasn't working then and it = doesn't work now. </SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <DIV><FONT size=2><SPAN class=242401306-21042003>When I started = putting in soundboards of my own I originally patterned my procedure after that = used by the factories I had visited. Primarily the one mentioned above. I built a = wood conditioning room to maintain my spruce at 4.0% moisture content. I = bought my spruce from the same source and to the same or better grade. I = edge-glued the stock in the same way. I planed it to the same thickness. I cut the ribs = to the same dimensions and glued them up the same way. And I got the same = results. Some sounded great, some deteriorated much more rapidly than I thought they = should. Ultimately, in spite of the impressive marketing I came to realize there = were some inherent problems. Problems which were inherent to the process, not = to the control over the process or the quality of workmanship involved. The = more I learned about the nature of wood the more I realized that this process = simply asked more from the wood that God ever intended--it's compression = strength is simply not adequate to support the loads the process imposes on it. </SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <DIV><FONT size=2><SPAN class=242401306-21042003>That realization = led me to investigate alternative methods and I gradually switched over to a = nearly 100% rib-crowned system. But it was the tone performance of the two systems = that led me to make the switch. Not just the idea of crown.</SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <DIV><FONT size=2><SPAN class=242401306-21042003>So, yes, we have = and continue to compare the tone quality of the two systems. From experience I would = say that given two systems working equally well the tone quality of the two = systems is approximately equal. I've not really been able to isolate much in the = way of real differences. But--and here is the big but!--the rib-crowned system = is inherently more predictable, more consistent and more reliable. = Especially over the long term. And when I walk into the showroom of a store selling = instruments with purely compression-crowned soundboards and I find eight out of ten = with the upper third of their scales sounding seriously short and percussive to = the point of being unacceptable yet carrying price tags in the $50,000 plus range = I have to think there is a problem there somewhere. And, no, I don't buy the = notion that it is simply poor workmanship. I've been in that factory and have = seen their workers on the job. They are as good at what they do as any = others. It is the design and the system that is at fault--not the men and women = working to the design.</SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <BLOCKQUOTE dir=ltr style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV><SPAN class=242401306-21042003><FONT color=#0000ff = face=Arial size=2>While building soundboard that are supposed to travel and be = installed in a repaired instrument far from the soundboard building place it is understandable that crown compression (and not only  if I = understand well) is used, but how can you attain an internal assembly tension as = high and then a delay in springiness response with the ribs as the most active elements?</FONT></SPAN></DIV></BLOCKQUOTE> <DIV><FONT size=2><SPAN class=242401306-21042003>I don't understand = this comment/question. A compression-crowned soundboard assembly will begin = to degrade immediately upon being exposed to normal room temperature and = humidity. Installing the assembly in a piano rim and loading it simply speeds up = the degradation. It doesn't really matter where the board is ribbed or where = it is installed. A rib-crowned soundboard assembly is not really stressed = until it is installed in the rim and then loaded with string = bearing.</SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <BLOCKQUOTE dir=ltr style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV><SPAN class=242401306-21042003><FONT color=#0000ff = face=Arial size=2>Are not we using this process to build the internal spring rate of the = soundboard ? </FONT></SPAN></DIV></BLOCKQUOTE> <DIV><FONT size=2>Well, stiffness, anyway.</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <BLOCKQUOTE dir=ltr style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV> <SPAN class=242401306-21042003><FONT color=#0000ff = face=Arial size=2>Being not experienced in these process I certainly will not = argue on those matters with you, but I seem to recall that even Del was = building so called "compression crowned soundboard in its early stages"  BTW = thanks, Del for your clearing on the "neutral fiber laying" it was exactly = that concept I was talking of .</FONT></SPAN></DIV></BLOCKQUOTE> <DIV><FONT size=2><SPAN class=242401306-21042003>Yes. But it was = because of my experience with the compression-crowning technique, both my own and = studying the product of the factories using it, that I began looking for alternatives.</SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <BLOCKQUOTE dir=ltr style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN class=242401306-21042003>Everybody agrees we could build pianos = without any crown if necessary, so </SPAN>t<SPAN class=242401306-21042003>he = presence of crown is not the only proof of the taste of the pudding I'd say!</SPAN></FONT></FONT></FONT></DIV></BLOCKQUOTE> <DIV><FONT size=2><SPAN class=242401306-21042003>Well, we could. But = we might have to alter our perception of the kind of tone quality we are after.</SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <BLOCKQUOTE dir=ltr style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN class=242401306-21042003></SPAN></FONT></FONT></FONT> <FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN class=242401306-21042003>Well the next soundboard I will build I = will use S shaped ribs and a compressssed sssshaping method . Or we'll do = again a soundboard with strings on the 2 sides to produce eventually a double = vertical (for twin brothers or sisters that should be nice).</SPAN></FONT></FONT></FONT></DIV></BLOCKQUOTE> <DIV><FONT size=2><SPAN class=242401306-21042003>Just build a nice compression-crowned soundboard assembly and it will develop automatically.</SPAN></FONT></DIV> <DIV><FONT size=2><SPAN = class=242401306-21042003></SPAN></FONT> </DIV> <DIV><FONT size=2><SPAN class=242401306-21042003>Del</SPAN></FONT></DIV></BODY></HTML>