Counterbearing (& Kowmung report)

Ron Overs sec@overspianos.com.au
Mon, 31 Mar 2003 10:00:27 +1000


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Hi David and all,

I've just returned from a weekend away at the Kowmung Music Festival 
(held each year in the picturesque Blue Mountains town of Oberon, 2 
hours drive west of Sydney). 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 
=46estivals.

=46or those who may be interested, the English language version of the 
Kutrowatz Duo website can be found at;
http://www.duokutrowatz.com/English/english.html

The Kutrowatz Duo performed on our piano no. 3 and a B=F6sendorfer 225. 
The original plan was that they would use two of our pianos, but 
since we are still building piano 4, we hired the B=F6sendorfer 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 Blue Rondo A La 
Turk 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.

At 6:58 PM -0800 29/3/03, David Love wrote:

>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.

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 (quite a number of 
default 'experiments' are taking place elsewhere in the world as we 
speak). 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.

>  What is the maximum angle in the capo section that you can get 
>without risking breaking strings.

I would not recommend over fifteen degrees in the capo sections.

>  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.

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 (and it will), the 
friction can be considerable, regardless of the base material 
softness.

Best,

Ron O.
-- 
_______________________

OVERS PIANOS - SYDNEY
Grand Piano Manufacturers

Web: http://overspianos.com.au
mailto:info@overspianos.com.au
_______________________
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