[pianotech] FW: RE: New Ask Physicist question

[David Ilvedson]

I think I understand it a little better...mechanical energy transformed into sound energy...

David Ilvedson, RPT
Pacifica, CA  94044

----- Original message ----------------------------------------
From: "Delwin D Fandrich" <del at fandrichpiano.com>
To: pianotech at ptg.org
Received: 5/18/2009 12:15:19 PM
Subject: Re: [pianotech] FW: RE: New Ask Physicist question


>| -----Original Message-----
>| From: pianotech-bounces at ptg.org 
>| [mailto:pianotech-bounces at ptg.org] On Behalf Of Stéphane Collin
>| Sent: May 18, 2009 9:05 AM
>| To: pianotech at ptg.org
>| Subject: Re: [pianotech] FW: RE: New Ask Physicist question
>| 
>|
>| - If we talk acoustic pressure level, the one caused by the 
>| strings is very low, due to small surface of the strings and 
>| huge short circuit effect of the air surrounding them when 
>| they move.  The one caused by the driven soundboard is much 
>| higher, even considering the reduction of kinetic energy 
>| after its transfer from the strings to the soundboard, 
>| because of its large surface.  So, one can say that the 
>| soundboard is an acoustic pressure amplifier of its driving 
>| strings.  Not ?

>No, not. It is not "sound pressure" produced by the vibrating strings that is
>causing the soundboard to vibrate and produce a greater "sound." It is the
>mechanical energy in the strings that is being transformed, or transduced, into
>sound energy. Mechanical energy (vibrations) is coupled via the bridge to the
>soundboard assembly where, by the forced motion of the soundboard assembly
>(still in the form of mechanical vibrations), sound energy is produced in the
>surrounding air. Nothing is amplified.

>ddf