<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Counterbearing (& Kowmung report)</title></head><body> <div>Hi David and all,</div> <div><br></div> <div>I've just returned from a weekend away at the Kowmung Music Festival<font color="#0000FF"> (held each year in the picturesque Blue Mountains town of Oberon, 2 hours drive west of Sydney)</font>. Visiting artists the Kutrowatz Duo (Eduard and Johannes) from Austria were again most impressive. Similarly impressive performances were given by a number of Australian pianists and instrumentalists over the two weekends of the festival. On Sunday 22 the Sandy Evans quartet performed in the first jazz concert to be featured at a Kowmung Festival. Her outstanding artistry on Saxaphones was complimented by drummer Toby Hall, bassist Lloyd Swanton and pianist Allister Spence, with guest artist Peter Jenkin on bass clarinet. For many Kowmung patrons, this performance would have been their first attendance at a jazz concert. The standing ovation they gave the quartet would tend to suggest that jazz will become mainstream, alongside classical, for future Kowmung Festivals.</div> <div><br></div> <div>For those who may be interested, the English language version of the Kutrowatz Duo website can be found at;</div> <div>http://www.duokutrowatz.com/English/english.html</div> <div><br></div> <div>The Kutrowatz Duo performed on our piano no. 3 and a Bösendorfer 225. The original plan was that they would use two of our pianos, but since we are still building piano 4, we hired the Bösendorfer 225 form the ABC Ultimo Center. While Eduard and Johannes are most proficient and sensitive classical pianists, they seem equally capable of turning their hand to jazz repertoire when required. Their two piano transcription performance of Dave Brubeck's<i> Blue Rondo A La Turk</i> was most exhilarating. Although it was not included in the programme, neither was the heavy rain on the tin roof of the Middle Creek Cattle shed. In the true spirit of professionalism, they decided treat the audience of 300 with a work which would cope with the poor signal to noise ratio. The audience responded to the outstanding duo brothers with a standing ovation.</div> <div><br></div> <div>At 6:58 PM -0800 29/3/03, David Love wrote:</div> <div><br></div> <blockquote type="cite" cite><font size="-1">I meant to ask one other question.  My recollection is that the ideal angle leaving the capo section up to the counterbearing bar is 17 degrees.  I'm not sure why that number sticks in my head--I may have gotten it from a piece that Ron Overs wrote, or I may be mistaken entirely.</font></blockquote> <div><br></div> <div>I believe that, where possible, the counterbearing angle behind the agraffe section should not exceed fifteen degrees or be much less than 10. While it is possible to set the counterbearing behind the agraffes to be higher than 15 degrees without risking wire breakage, it will tend to accelerate the deformation of the agraffe. This will lead to premature 'string noise'. Furthermore, while it is desirable to have quite a short string segment between the agraffe and the counterbearing bar/felt, the tendency of a great many manufacturers is to overdo it. If the segment is made too short, it will tend to 'shut down' the freedom of the speaking length. I ran some experiments back in 1995 which proved this to my satisfaction. Now while I'm not prepared to publish details of this on the Pianotech list, for those of you who are interested, conduct your own experiment to draw your own conclusion. Just remember that human flesh has high hysteresis loss characteristics<font color="#0000FF"> (quite a number of default 'experiments' are taking place elsewhere in the world as we speak)</font>. So if you are tempted to hold a test piece of metal in your hand, you will need to insure that you de-couple the hysteresis loss.</div> <div><br></div> <blockquote type="cite" cite><font size="-1"> What is the maximum angle in the capo section that you can get without risking breaking strings.</font></blockquote> <div><br></div> <div>I would not recommend over fifteen degrees in the capo sections.</div> <div><br></div> <blockquote type="cite" cite><font size="-1"> I would assume the materials would make a difference too.  In the capo section where the strings bear against cast iron, I would assume that they would tolerate less of an angle than where the strings where redirected by softer brass agraffes.</font></blockquote> <div><br></div> <div>I'm not so sure about this, but I have not conducted experiments to prove it either way. However, once the piano wire has cut a significant groove into a brass bar or agraffe<font color="#0000FF"> (and it will)</font>, the friction can be considerable, regardless of the base material softness.</div> <div><br></div> <div>Best,</div> <div><br></div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div>_______________________<br> <br> OVERS PIANOS - SYDNEY<br> Grand Piano Manufacturers<br> <br> Web: http://overspianos.com.au<br> mailto:info@overspianos.com.au<br> _______________________</div> </body> </html>