31. Vibration intensity (2-4, order by PIN weight)

[ 01/31/2018 ]     Labels: 31..Intensity-TopPlate

 
Measured vibration intensity data(from 'on floor') were sorted in order of endpin weight.
There seem to be some tendencies:

(1) The behavior of top plate rather shows the similarities in the pattern between 'without pin' data and 'carbon'(:the lightest endpin).

(2) The heavier endpin selected, to the lower area shifts the vibration-center of the top plate slightly, and moreover, the mechanical vibration seems getting integrated along the whole length including the endpin.

エンドピン重量順に測定データを並べてみると、最も軽いカーボンの場合はエンドピンなしのパターンに似ており、エンドピンが重くなると最大振動中心が胴体の下方向へ少し移動して、さらにエンドピンを含めた全身振動にシフトしていくように見受けられる。

31. Vibration intensity [ Measurement 2-3 ]

[ 01/28/2018 ]     Labels: 31..Intensity-TopPlate

Vibration intensity data of cello on the top-plate, tailpiece and endpin were measured using a '8mmD' iron rod (iron alloy rod) endpin. The length of the endpin is 535mm, weight 224g(..rather heavy).

(1) Like as the previous measurements(10mmD endpin), when the tip of endpin is placed on the floor and restricted to vibrate, the vibration intensity/pattern of endpin or tailpiece changes remarkably.

(2) Cello without an endpin vibrates using its whole wood body, however if an endpin is added, the mechanical vibration seems to shift along the whole length including the endpin.

(3) Advanced Endpin Holder(AEH-011) can create the mitigated situation from the alliance vibration of endpin, tailpiece and the floor.

8mmφの鉄(棒)のちょっと重いエンドピンでの振動挙動を調べました。先般の10mmφエンドピンとよく似た傾向。エンドピンなしでは当然チェロ胴体全体で振動しますが、ピンを付けるとピンを含めた全身振動にシフトしているかのようです。
Advance Endpin Holderはこれらの乖離の中間状態を実現しているように見えます。

Device : Vibration meter VB-8205SD
Cello  : 110-year-old German cello
Endpin : 8mm(D) iron alloy rod, 28cm(11in) below tailpin
Data   : 10 data by pizzicato were averaged at each measurement point

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

31. Vibration intensity -Measurement 2-

[ 11/24/2017 ]     Labels: 31..Intensity-TopPlate

 
Top-plate's vibration intensity was measured again including tailpiece data.

MEMO:
When the tip of endpin is placed on the floor and restricted to vibrate, the influence seems to extend over whole cello. 

(1)Endpin changes its vibration patterns remarkably.
(2)Tailpiece increases its vibration intensity.
(3)Top-plate slightly weakens the vibration in general or shifts to the flat(/even) vibrations at least along the vertical direction.

Device : Vibration meter VB-8205SD
Cello  : 110-year-old German cello
Endpin : 10mm(D) steel pipe, 28cm below tailpin
Data   : each 10 measurements averaged
 

31.Vibration of cello (intensity): Top plate C(66Hz) Pizzicato

Excluding strings or the bridge, the maximum vibration spot of the cello was unexpectedly found to be the tip of the endpin when the cello was lifted up in the air and a lower C note played (See Fig. 24).
 
空中で低音(C音のピチカート)を弾いた時、エンドピンの先端で胴体のそれを上回る最大強度の振動が観測された。 ( 参照: Fig.24 )

[ 9/19/2016 ]      Labels:  32..Intensity-TopPlate

31.Vibration of cello (intensity): Top plate G(98Hz) Pizzicato

[ 9/18/2016 ]      Labels:  31..Intensity-TopPlate

31.Vibration of cello (intensity): Top plate D(147Hz) Pizzicato

[ 9/17/2016 ]      Labels:  31..Intensity-TopPlate

31.Vibration of cello (intensity): Top plate A(221Hz) Pizzicato

[ 9/16/2016 ]      Labels:  31..Intensity-TopPlate