<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: More CC vs RC questions was RE: Killer Octave & Pitch</title></head><body> <div>Hi Clarke,</div> <div><br></div> <div>At 9:05 AM -0500 18/2/05, Clark Sprague wrote:</div> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">Also, Ron, I noticed that the bridge in your D has the treble and bass bridges connected in a U shape.  We have a used Yamaha C-7 from the 1970's, I think, that has the same configuration.</font></blockquote> <div><br></div> <div>Yes, and Steinway used it long before Yamaha took it up.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">  What is that all about?  For stiffness, or what?  Clark</font></blockquote> <div><br></div> <div>The bridge shown in the image was the original Steinway D 'ring' bridge (which we did not use for the new sound board - we designed new bridges, with a new string scale). In the 'ring' design both the bass and treble bridges are joined. I do not use this system since I want the low bass to be more flexible than the lower end of the treble bridge, so I always use separate bridges without the join. The original ring is fitted to help impedance at the lower end of the long bridge, but it has the disadvantage of killing the low bass.</div> <div><br></div> <div>And in another post Clark wrote:</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">. . .  how do you figure how big this "fish" should be, and how do you come up with what size the soundboard should be?</font></blockquote> <div><br></div> <div>When rebuilding a piano, I stand at the instrument and think about the original distribution of area, and think about what distribution area might yield an improved result. For this D, I drew in a spring lathed 'ideal' position for the 'fish' on the old board before removing it. Then I drew a second fish area which reverted about 30%  back towards the original area. I didn't want to risk going too far in one step. The next board reduction will probably conform very closely to the first area reduction I drew onto the old board.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">  (ie: where to place the cutoff bars?)</font></blockquote> <div><br></div> <div>I consider the cut-off bar placement similarly. Another unachievable but desirable feature is placing the long bridge to run more or less down the centre of the belly. The bridge itself can't be moved since the string scale is dependent upon its position, but a cut-off will help. Another significant cut-off benefit is that it will allow for considerably reduced rib lengths for the middle order ribs. These are typically grossly overloaded in a conventional non-cut-off design.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1"> Why should the manufacturers, for many decades advertise that the bigger the soundboard area, the bigger the sound, and then we put in cutoff bars to decrease that "essential " size?</font></blockquote> <div><br></div> <div>Because we live with many myths in our industry, and that's another one of them. Bigger can be better but it depends on where it is bigger. The well established convention with Hi-fi speakers is that a large-area woofer is used for the low frequencies, where a larger surface area is required to achieve air movement at lower frequencies, and a smaller area tweeter to produce the higher frequencies. The woofer, with its relatively high area-to-mass diaphragm would be incapable of the relatively faster reaction required to produce the higher frequencies, causing the large diaphragm to distort across its face if asked to do so. The high frequency driver, with its relatively small surface-area-to-mass rigid diaphragm is designed to react extremely quickly to faithfully reproduce the higher frequencies which it handles.</div> <div><br></div> <div>You can simplistically think of a piano sound board as a multi-range speaker diaphragm, which is expected to reproduce frequencies from 27.5 to 4186. Its a big ask. Ideally, as with speaker design, it should have a larger area for the lower frequencies, with a progressively reducing area as the frequency increases. A sound board without a cut-off won't remotely conform to this objective. If you look at a grand piano in its typical concert grand form with a very small or no cut-off, you have a large area around the bass bridge, an even larger area in the middle where it could be reduced to significant advantage, and a top area which sometimes has 'half a football field' out behind the bridge - which also could be reduced to advantage. Typically, the longer the piano, the bigger the area behind the long bridge at the top. I suspect that makers have done this for two reasons. Firstly, because of the myth that bigger is better, and secondly to keep the proportions of the piano looking 'right' from a styling perspective.</div> <div><br></div> <div>I like to think of the ideal grand piano sound board area as a 'bent tear drop' shape. The bass should have the largest surface area because it is being asked to produce the lowest frequencies. Similarly, the mid areas should be of less area and the high treble should have the least of all. When designing a new piano, we have the most flexibility, but we still have to ask the same questions and come to a decision, and it will be from our experience and judgement only that we derive the final dimensions. Unless of course, we take the more ordinary route of copying what someone else has done before us. Of course, we should consider the design decisions of those who have come before, but we should not feel bound by their decisions. Their idea at the time was just that. They had to make the same decisions then, as we are making today. We should not constrain today's possibilities by cloning what has gone before. By all means look at and consider the design parameters of the dinosaur, but don't replicate the entire beast. Evolution must properly make, from the current crop of front runners, the champion of the new age. The new champion may or may not be your creation, but its judgement day will surely come.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">  There are others out there who would like to "tool up" to do soundboards, as well, and do them well.</font></blockquote> <div><br></div> <div>The more the better.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">  How do you figure out how to design soundboards with the knowledge that seems to be expanding all the time? </font></blockquote> <div><font face="Arial" size="-1"><br></font></div> <div>It will always be an evolving process based on current knowledge and experience. I have been thinking about piano design parameters, including sound board area, since my first year as a piano technician in 1975. I remember spending so many years tuning on 'autopilot', pondering about the design and layout of the piano I was tuning, and considering how the various design parameters were influencing the tonal outcome.</div> <div><br></div> <div>Knowledge in our discipline is expanding all the time. We are living at a time when 300 years of combined thinking has resulted in what we have come to know as the modern piano. It is essential that this thinking and evolution should be allowed to continue. Further progress remains possible as long as we don't let the politics of the currently-successful ones get in the way. We must always endeavour to work out what is a worthwhile design feature, and what might be a dead end idea. The black art of piano design is fascinating, and there remains an ocean of improvements waiting to be found. As with the evolution of species, many subspecies will come and go like the Dodo. Not all will be bad ideas, and some may be worthy of resurrection. But new Dodos will come along as well. We must use our judgement to establish what we believe to be the best combination of established practice, past practice and future possibilities. Getting the three together in the best proportion, when building a new instrument, can be somewhat akin to jumping off a cliff in the hope that there is a soft landing at the bottom, and not just rocks.</div> <div><br></div> <div>You also have to contend with a multitude of 'technical' opinion, which sometimes hasn't even been down the 'thinking road' you have taken. So often this chorus will discount the new idea just because it is different and 'not the way' their favourite manufacturer does it. It doesn't necessarily mean that the new idea hasn't got merit, but you have to somehow carry on through the 'thunderstorm' of disbelief which surrounds you.</div> <div><br></div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font face="Times New Roman" size="+1" color="#0000FF"><b>OVERS PIANOS - SYDNEY</b></font></div> <div><font color="#000000"><i>   </i></font><font color="#0000FF"><i>Grand Piano Manufacturers</i></font><font color="#000000"><br> _______________________</font></div> <div><font size="-2" color="#000000"><br> </font><font color="#000000">Web http://overspianos.com.au</font></div> <div><font color="#000000">mailto:ron@overspianos.com.au<br> _______________________</font></div> </body> </html>