Killer Octave

[Ron Overs]

Richard wrote:

>I have been thinking about this whole idea of using springs for this kind of
>thing... artificial crown if you will... We've had it up several times for
>discussion and a couple methods have been sketched out. But what about useing
>some kind of leaf spring approach ? I can kind of picture strong leaf springs
>between beams right under and exerting uwards pressure on ribs. Would these be
>able to supply enough upwards force, and would they perhaps have less
>detrimental effects on the soundboards ability to move then other spring types
>might ?

The problem with leaf springs is that they have hysteresis loss when 
compared to coil springs. This is why road trucks can be built 
without shock absorbers when leaf springs are employed. The 
hysteresis loss of leaf springs would contribute further to loss of 
sustain.

While on the topic of the killer zone, I suspect that the 'tone 
collector' of Steinway pianos might indeed be a 'tone dissipator'. If 
you check the location of the connection bolt from 'collector' to 
plate, you will notice that it connects adjacent to the so called 
'killer' zone, or should we say 'killed' zone. Just last week I 
crawled under a D to feel the movement at the collector bolt under 
heavy playing (try it - you'll be amazed). The next D I rebuild (if 
it ever happens again) will likely get another beam and set bolt in 
place of that suspect device. I'm not suggesting that the problem is 
the 'collector' alone, but I suspect it is contributing to the 
problem. It would be interesting to compare the Yamaha CFs with and 
without the tone collector. Gosh its good to see marketing dictating 
design as usual isn't it?

I think I'll go before things get out of hand.

Ron O
-- 
Overs Pianos
Sydney Australia
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Web site: http://www.overspianos.com.au
Email:     mailto:ron@overspianos.com.au
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