Home History Acoustic vs Electric Producing Tone Acoustic Amplification Electric Amplification Bibliography
Acoustic Amplification
- Take a string (guitar, kite, rubber band, etc) and secure a
length of it at two ends. Pluck it. The sound heard is
caused by the motion of the string.
- When the string vibrates at a certain frequency, say 440 Hz
(musically, A), it compresses the air around it at the same
frequency.
- This change in pressure, or sound wave, propagates outward until
it reaches the ear drum.
- The difference in the change in pressure and natural intercranial
pressure cause the ear drum to vibrate at the original frequency, which
is how the ear receives sound.
- The string alone is not very loud. That's where acoustic amplification comes in! On a guitar, sound is amplified by the whole body of the guitar.
- The vibration of one or many strings cause the saddle of the bridge to vibrate.
- The vibration of the saddle causes the soundboard, or the face of
the guitar body, to vibrate.
- The soundboard acts as a diaphragm, compressing air inside the
body at the same frequency as the string.
- Compression forces the air out along the path of least
resistance, the soundhole, at a much louder volume than the string
alone could have created.