31. Vibration intensity -Measurement 2_2-

[ 12/14/2017 ]     Labels: 31..Intensity-TopPlate

Vibration intensity of cello on the top-plate, tailpiece and (this case -->) carbon endpin:

When the tip of endpin is placed on the floor and restricted to vibrate, the vibration patterns of endpin and tailpiece change remarkably and the vibration intensity increases. As a result, the influence seems to extend over whole cello.
There seems to be some difference between the result from a steel pipe endpin and a carbon-fiber, but this phenomenon probably comes from the essential mechanical/structural issue of the endpin-built-in-cello.
エンドピン材質により若干の違いはあるものの、床置きしてエンドピン先端の振動が止められると、チェロの振動は大きく影響を受けて変化します。

Device : Vibration meter VB-8205SD
Cello  : 110-year-old German cello
Endpin : 10mm(D) carbon, 28cm(11in) below tailpin



82..Cello -Response and Resonance 4-

[ 11/18/2017 ]      Labels:  94.Video & Study

 


This exaggerated simulation suggests a simple and important truth.
The sound speed in the air is far faster than the speed of top-plate vibration. Actually it is probably 100 times or more.
If so, cello's all sound color/quality and even overtones might be created by the top-plate(or body)'s mechanical vibrations rather than acoustic resonance.
Furthermore the top-plate/body reflects the influence from tailpiece, endpin and the floor.
Players encounter poor resonance at rainy day. It will be because the resonance is generated by wood plate.

空気中の音速はチェロの表板の振動速度より遥かに速い。
これは楽器の音色・響き・倍音さえも表板自体が創り出していることを示唆しているように見えます。床やエンドピンの影響も反映されます。
雨の日に響きが悪くなるのはなぜでしょうか。楽器のディメンションや音響構造の話ではなく、単純に響きや音を造るエンジンが木製であることに起因すると考えられます。

BGM: YouTube free sound

82..Cello -Response and Resonance 5-

[ 12/02/2017 ]     Labels:  94.Video & Study

 
Cello takes 10-20 Hz slow swing(/vibration) along its whole-length.

BGM:
Brandenburg Concerto No4-1 BWV1049 - Classical Whimsical by Kevin MacLeod is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/)
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100303
Artist: http://incompetech.com/