Questions on sound waves/air blowing/wind

[carlteplitski]

Many years ago when I worked as a service tech., doing other instruments other than piano, 
I reconed speakers, and did much work on organs, etc.   One day I went to look at a quite large 
Kawai organ in a dealers store. The problem was a lack of punch, or volume. Everything seemed 
normal, but no juice.  After looking at this thing for some time, I noticed that the 2 big speakers had
the color wires hooked - up backwards. Of course those who are in the know , realise that this put
the 2 speakers out of faze with each other. One speaker was moving out , while at the same time the 
other was moving in. In effect cancelling each other out , by lessening the amount of air either speaker
could move.  This was a great example that the movement of the speaker cone produced the air movement
which produced sound. When I reversed the wires on one speaker, the sound was amplified considerably.
I think the speaker moved the same amount, so the problem wasn't electrical .   

Another example is when a string has a false beat, sometimes tuning a string
in the same triad, will lessen or even cancell out the beat produced by the single.  I assume that what is
actually happening is that the false beat is flat and the next string tuned will be a little sharp and cancell.
Not sure this is the reason, but my mind sees it that way. If anyone has a better explantion, I'd sure like to hear it.

Carl / Winnipeg

----- Original Message ----- 
  From: paul bruesch 
  To: Pianotech List 
  Sent: Friday, January 25, 2008 9:18 AM
  Subject: Re: Questions on sound waves/air blowing/wind


  Wind is an air mass that's moving, at a constant velocity, relative to a stationary body... the planet, you, a building, etc.  Sound is also air that's moving, but it's air that is moving not only relative to stationary bodies, but also relative to itself. A vibration is a molecule of air pushing the molecule ahead of it, but the molecule behind the one that's pushing isn't pushing, or even quite keeping up.

  You (or at least I) can feel sound... haven't you ever stood in front of the big woofer speakers at a concert or at the disco<g>?  

  I'm sure I'll get clarified or even (likely) corrected, but that's my explanation and I'm sticking to it, at least until I get clarified or corrected...

  Paul Bruesch
  Stillwater, MN (where it's warming up today... we're already at +4F!)


  On Jan 25, 2008 8:52 AM, <KeyKat88 at aol.com> wrote:

    Greeetings,

              This may sound elementary but, if sound waves are compressed and rarefacted molecules of air, then how is it that soundwaves are not wind, or air blowing...why can't you feel sound waves moving past your ear? ...(or can you feel them if the sound is loud enough?) This may sound crazy but, shouldn't a high note such as C88 make you feel colder  because its 4160cps of comp and raref's going past your body as compared with A0 at 27cps? Why arent sound waves enough to move air?

    This question has plagued me for a long long time.

    Thanks,
    Julia
    Reading, PA



              





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