Thank You David.
I believe I am the first person to do experiments like this on multiple pianos to determine characteristics, All the other studies i have seen focused on one instrument. I'm glad that i took this approach, as i am learning some interesting things not mentioned anywhere else that has real value tp me.
For instance, The Mason and Hamlin AA Chladni figure did not enter the top two sections in the treble. The Baldwin L in my shop also was the same as the MHAA. The Steinway O on the other hand did. I have confirmed this with the examination of those pianos rib scales. The Steinway ribs #8 and #7 are too weak. I'm sure it will be worse in a diaphramatic soundboard.
So the chladni figure is a good tool to check for that weakness. So don't copy a Steinway rib scale, it can be improved.
Regards to the fundamental frequency and what it should be. The lower the better. But there are engineering limits. In every case so far, i have seen where improvements can be made. The bigger the piano the lower the frequency will be. The Steinway O was the smallest of my three tests, and thus had the highest frequency. There will be comparisons when the new boards are installed as well. I'm looking forward to that.
I will be fixing ribs 8 and 7 in the new board and looking forward to that chladni figure.
-chris
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Troubles are Bubbles, and they just float away.
chernobieffpiano.com
grandpianoman@protonmail.comKnoxville, TN
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Original Message:
Sent: 06-16-2019 21:53
From: David Pinnegar
Subject: Steinway O Chladni Figure
Thanks so much for doing these experiments
Do all pianos have their f0 mode in the 40-50Hz region? What is the effect of lower?
Are the resonant modes expected multiples of f0?
When strings vibrate the soundboard below the resonant frequency is the projection of the instrument's sound different?
Best wishes
David P
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David Pinnegar, B.Sc., A.R.C.S.
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Original Message------
Chris,
Very interesting. What do you use (and how) to generate the frequency?
Pwg
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Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com
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