[ 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 )
