> We can argue about whether the soundboard is an amplifier or > not........ Why would anyone argue? Just look it up in the dictionary. > If one defines "amplification" as an increase of efficiency in the > system, then indeed there is amplification. But that is not the way > amplification is defined. Ummm, that doesn't make a whole lot of sense, if I may say so. You are correct that an increase of efficiency is not a correct definition of amplification. Why introduce "if one defines......? I could define concrete as the way I like my steaks done, but it really wouldn't be very useful..... ;-) NOW the horse is suitably flogged! Terry Farrell On Feb 16, 2011, at 11:41 PM, Paul McCloud wrote: > Terry, Bruce: > We can argue about whether the soundboard is an amplifier or > not, but it doesn't change the laws of physics. Energy in = energy > out. Nothing disappears, but energy transfers from one form to > another. > The energy that is put into the piano by forcing a felt-covered > stick to hit a string is not lost. The energy is dissipated in > different ways. If those strings are connected to a larger surface > area (soundboard) via bridges and ribs, some of that energy will be > dissipated by the movement of the board. Movement of that board > excites the air around it. That excited air has absorbed some > energy from the board and can be measured as sound pressure. The > rest of the energy will be dissipated by heating the wires, some > into the wood cabinet, the soundboard itself, etc. > A vibrating string by itself has so little surface area that the > amplitude of sound pressure is very small. Building a device (a > piano) that has the string energy coupled to a larger surface area > that moves a larger amount of air, an increased sound pressure > results. The only thing that has changed is that the system has > become more efficient in changing the energy of a vibrating string > into sound pressure. > If one defines "amplification" as an increase of efficiency in > the system, then indeed there is amplification. But that is not the > way amplification is defined. We do get more of what we wanted from > our vibrating string.by adding a sounding board. But It is > technically not "amplified", since the common use of the word > "amplify" means that some form of energy has been added to augment > the the system. > Now, if you add a microphone, pickup or other electronic device, > couple it to the vibrating string, connect it to an amplifier where > energy is added from an external source, and then connect a > loudspeaker to create sound pressure, you will achieve the same > result as adding a soundboard coupled to a vibrating string. Your > sound pressure levels are going to increase as you add energy (turn > up the volume). It will have, in the strict traditional > definition, have been "amplified". Making a system more > efficient doen't make it an "amplifier". > If you want to define it differently, you can start a cult. > The horse is now suitably flogged, and is now dead. My > condolences. > Paul McCloud > San Diego -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20110217/a7c78e0c/attachment.htm>
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