estebanana -> RE: flamenco body styles and bracing-where to start (Jun. 27 2011 21:18:25)
|
I should not even get into this, but first of all I vehemently second the opinion that a guitar is not an air pump. If you had to give the acoustic guitar a mechanical designation of some type it would probably be closer to a diaphragm and even then its too complex to be simply that. Second, just to clarify, sound waves are not 'born on the wind' or moving air, sound waves are pressure waves moving through the air, which is different than moving great quantities of air. Sound moves through air space the way waves move through water. Waves are created by a displacement of air or water or other medium and as a result of that displacement pressure waves are created. When those pressure waves reach your inner ear they vibrate the tiny delicate diaphragm mechanisms of your inner ear and nerves carry those vibrations to your brain where they are decoded and reconstructed as sound. When the bottom of the ocean moves and drops several feet because one tectonic plate slides across another it creates a subduction zone. Water is displaced, but clearly not pumped anywhere. The resulting disparity in pressure causes movement in the form of a wave which moves rapidly through the water column, but does not move all the water at the speed in which the wave itself is moving. A guitar top is a lot like this ocean bottom subduction zone scenario in that the top moves and creates pressure waves and those waves travel through the air as bumps of pressure. The air is not pumped from one place to the other even though from an anecdotal stand point it may seem that way. The way to think about this is to consider that the speed of sound at sea level is 768 miles per hour. So unless your guitar is moving air at 768 miles per hour past your face, it's not acting as a pump to push air as fast as the sound moves, nor is the sound itself being moved by air. What is happening _in reality_ { and i know a select few of you don't seem to like to think in terms of reality and guitar making or that guitar making has any relationship to reality} is that the guitar is working as a movable diaphragm to make pressure waves which _move through_ the medium of air. Any questions?
|
|
|
|