[CAUT] coupled motion and other myths

[Richard Moody]

-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of
Richard Brekne
Sent: Thursday, June 21, 2007 2:12 AM
To: caut at ptg.org
Subject: [CAUT] coupled motion and other myths

 

Hi Ric

The coupled motion of strings is a description of the physics behind how
more then one string effect both the termination and each other when put
into vibration.

It is a theory, not a description. 

There were experiments but they forgot to include the piano tuner.   As a
tuner I think I can demonstrate what they heard was a result of "tuning
instability." The internet is now the opportunity to say, "Hey, if you phd's
want to conduct experiments on pianos, we tuners can give you some insight."
But they are a little shy of tuners because if they do get it into theory,
(algorithm) they will have synthesized the sound of a piano into a computer
chip, and then can produce an instrument at 1/10 cost of "acoustic piano" at
10 times the profit. 

By the way, do you know who or how were the 5 lectures financed? 

 

---rm 

The so called pitch drop Virgil Smith, Dr Coleman and a host of others claim
is a related subject matter but it is not in itself the same thing.
It is in my opinion entirely possible that in some instances the pitch will
not drop, but raise... or not seem to be affected.  The reason for this is
also to be found in the 5 lectures.  The bridge impedance at each bridge pin
also must be considered. 

 decisive part of the attack portion of the sound the soundboard releases,
and that this effects the overall sound.  He also has some interesting
things to say about longitudinal vibration in the soundboard itself.

Yeah and you need the moon in Vergo to grow a very good tomato. 



There are many piano techs claiming to have far greater insights into these
subject matters then they can possibly have.

Really?   Then there are a few  who do have "greater insights"  Lets hear
from them. 

 The fact is there are a handful of bonified researchers out there with the
physics knowledge to describe adequately these things, 

          But do you think there are technicians who can also "describe
adequately these things,"?   

"these things" are the real life instruments that the techs build that the
bonified researchers out there with physics knowledge then "describe
adequately".    

I have no worry about the scientists synthesizing the sound of the piano.  I
can  help them do it and hopefully retire me and my generations in comfort.
It's a slim hope (it is about to happen, probably only  two years to act).


Anybody heard of psycho acoustics?    Google it, you won't believe what you
see/hear.   The "hit" below is one of many and is interesting for the first
part..

 


Experiments in  <http://www.dogstar.dantimax.dk/acoustic/acoust-1.htm>
Psycho-Acoustics, Introduction


Beat Frequencies: Finally, there is the phenomenon of "beat frequencies"
which is often explained as a psycho-acoustic mixing process. ...
www.dogstar.dantimax.dk/acoustic/acoust-1.htm - 26k -
<http://64.233.167.104/search?q=cache:9Ahb9iB6vfwJ:www.dogstar.dantimax.dk/a
coustic/acoust-1.htm+psycho+acoustics&hl=en&ct=clnk&cd=3&gl=us> Cached -
<http://www.google.com/search?hl=en&q=related:www.dogstar.dantimax.dk/acoust
ic/acoust-1.htm> Similar pages

 

 

PLEASE  I am not quoting the reference above as the truth, but as something
the might be of interest to piano tuners, or not, ,,, but it held my
interest for two pages. .. rm

 

 


Is this pitch drop that Virgil Smith mentions, is it the same as "coupled
motion"?  Did he call it that?  Who then came up with the name? 
    
I can demonstrate the opposite.  I can tune a unison that will show the
pitch rising from the first string tuned.  And this would be a unison that
agrees with any RPT.   Lets do it at a convention.  I will pay for the booth
if each visitor chips in a dollar.  (As an added truth, I can also
demonstrate it can go down in an acceptable unison.)  That ought to make it
worth $2.00 a visit.    Richard Moody     

 

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