50. C(66Hz) Endpin-tip vibration data

[ 3/29/2017 ]     Labels:  48..Beat.Endpin

[ comment ]
On a stand(,endpin is floating in the air),
bridge takes natural beat pattern (e.g. 4->3->2->3->2-) during fading out, and the endpin-tip unexpectedly ceases the vibration in a short time.

With endpin and placed on the floor,
both bridge and endpin keep mainly constant 4-beat, moreover the endpin has a long vibration duration.

On Advanced Endpin Holder(AEH-011),
bridge has rather a similar beat pattern to the case of 'floating' cello and the beat of endpin-tip is also similar to the bridge. The duration time of the endpin-tip is medium between above.


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3 sec after a C(66Hz, open string) pizzicato
Cello: 110-year-old German cello
Endpin: 10mm(D) steel pipe, 28cm(11in) below tailpin
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Please remember some findings at Label-47.(Propagation).
(1)The beat pattern of bridge very linked to that of the center area of top plate.
(2)Without the endpin, cello body naturally faded out taking beats e.g. 4->3->2->3->2->1, but when with the endpin and placed on the floor, the bridge kept characteristic flat 4-beat.

In this case, 110-year-old instrument is probably consisted of stiff wood, although the results might be slightly different from Label-47., but the structure of the cello is basically the same. Common inclination should also be expected.
 

50. Research focusing on the vibration of endpin-tip

[ 3/21/2017 ]     Labels:  48..Beat.Endpin

Let's make a further research effort focusing on the vibration of tip of endpin.


50. The vibration of endpin-tip

 [ 3/19/2017 ]     Labels:  48..Beat.Endpin

Two video samples show the the vibration of endpin-tip after a C(open string) pizzicato.
[Top:] (1)Contact(flat) microphone data measured at the tip of endpin and (2)usual sound microphone data in the room.
[Bottom:] A small dental mirror was installed at the tip of endpin. The mirror casts small spotlight about 3 meter away.

In this 40 sec video the endpin mainly vibrated 64-65 times. We can also recognize the vibration in video as '96-100 tempo'. 

It just matches the calculation of C(66Hz, 15.2msec, fundamental) vibration : 66Hz * 60sec / 40slower = '99 tempo'

In the measurement, contact microphone detects internal 6/5/4,, beats in a cycle period.
A reflection of light in the mirror takes a stiff oscillation and gives us a premonition of existence of these tiny beats.

Video: 1 sec after a C(open string) pizzicato, 40 times slower
Cello: 110-year-old German cello on stand
Endpin: 10mm(D) steel pipe, 33cm(13in) below tailpin
Camera: SONY RX100-4 ( zoomed to two times )






A0. Advertisement

 [ 3/14/2017 ]     Labels: A0.Advertisement

Behind their concern about toes, cellos still retain the innate great capabilities to sing and dance.
Need further researches.



A1. Available angle

 [ 3/02/2017 ]      Labels: A1..AEH

Advanced Endpin Holder(AEH-011, 012) requires your cello to be kept a proper angle from the floor. 
In case that the diameter of the tip of your endpin is 8 mmΦ, the placing angle of your cello should be at between 45 and 90 degrees. Please avoid to take a shallow angle. 
浅すぎる(チェロ)角度での利用を避けてください。