A typical resonance simulation for 4C0C(C 66Hz on C string, the lowest note on cello) was carefully studied by 70 times slower. The behavior was very similar to a former study of 4C4E(83 Hz). For a C(66 Hz) down-beat given from strings, cello body(/top plate) resonates adopting 3 to 5 up-beats those are taking low angle vibration(:along a round slice direction ). Just like an E(83 Hz) resonance, when a cello placed on the floor with endpin, the long endpin or prolonged height cannot keep rigorous up-beats no more, slightly delayed and shifted pitch brings endpin an 'interference beat'. Consequently, cello body creates a new macroscopic single-beat along the height direction, reducing the round slice resonance and the amplitude instead.
チェロの最低音:C音(66Hz)の 70倍スローモーション-シミュレーションである。E音(83Hz)の場合とよく似ている。 C(66Hz)の場合、弦振動の頭打ち(1周期=15mS)に対してチェロの表板は、3~5ビートの裏拍を打ちながら共振している。エンドピン無しの場合もエンドピン装着時のいずれでも胴体の輪切り方向の振動を基調としている。 エンドピンを装着し床置きした場合、チェロの身長が伸びた形となるために、正確な裏拍を形成できなくなりエンドピンに1周期あたりに大きな 1ビートの「うなり」を生じ、縦伸び振動を生じていると考えられる。その一方で輪切り方向の(低角度の、楽器の音量に貢献する)響きが抑えられていると考えられる。 Left : Without endpin Right: On floor, with 8mmD Metal rod endpin Cello: Cello-1 (8-year-old) 70 times slower simulation, silent video
Cello body creates a new macroscopic single-beat along the height direction on the floor, at the same time, with muting the round slice resonance. (全体としては身長方向に1ビートの縦振動を生みだしている)
Left : Without endpin Right: On floor, with steel pipe endpin Cello: Cello-1 (8-year-old) 160 times slower simulation, silent video (same post: https://advancedendpinholder.blogspot.com/ 70h. E(83Hz) on C-string Simulation x160 slower)
The time delay between two microphones located vertically and horizontally enables us to guess the resonance direction of cello. Sound speed in the air is 100 times(or more) faster than the vibration speed of top-plate.
F note on C-string(88Hz, 4C5F, bowing) Typical Resonance Simulation: Cello body resonates taking a 2-beat for F(88 Hz). Endpin also resonates itself taking favorite beats according to each material/length with the cello body. As a result, the lower part of body seems to be repressed a little bit when placed on the floor. (C線のF音、チェロ胴体は2ビートで共振しエンドピンは独自の共振ビートを取っている。その結果、胴体下部の振動が若干押さえられているように見える。)
Cello: Cello-1 (8-year-old) 80 times slower, silent video Reference post: --> https://advancedendpinholder.blogspot.com/ --> 94..Resonance Direction-C --> 94..Cello-1 on C(C-G) Resonance Direction and V/H-Ratio
Left : Without endpin Right: Floating, with carbon endpin
Left : On floor, with Titanium endpin
Right: On floor, with 8mmD metal-rod endpin
G note on C-string(98Hz, 4C7G, bowing) Typical Resonance Simulation: Cello body takes a single beat resonance in spite of various endpin environments. G(98Hz) note seems to be the lowest frequency that cello body can resonate by a single swing. (C線のG音、チェロが胴体全体を使って1ビートで共振できる最低音のようです。)
Cello: Cello-1 (8-year-old) 80 times slower, silent video
Reference post: --> https://advancedendpinholder.blogspot.com/ --> 94..Resonance Direction-C --> 94..Cello-1 on C(C-G) Resonance Direction and V/H-Ratio
Left : Without endpin Right: Floating, with carbon endpin
E note on C-string(83Hz, 4C4E, bowing) Typical Resonance Simulation: On cello's low notes(C - F#), down beats from C-string need to be added cello body's up beats and completed by. However the extended height of body by deployed an endpin misses ideal up beats and weaken the resonance amplitude. (C線上のE、エンドピン装着によりチェロは裏拍をうまく刻めず結果として十分な共鳴を実現できていません)
Left : Without endpin Right: On floor, with steel pipe endpin Cello: Cello-1 (8-year-old) 70 times slower, silent video
Reference post: --> https://advancedendpinholder.blogspot.com/ --> 94..Resonance Direction-C --> 94..Cello-1 on C(C-G) Resonance Direction and V/H-Ratio
D# (1A6D#, 313Hz, 3.20mS) Typical Resonance Simulation: Oscilloscope charts below show us a clear gap in phase between V-mic and H-mic. In this case, the resonance direction is not along round-slice-level of cello but along the height(neck - tail pin).
Without endpin(left) vs Steel-pipe endpin floating(right) Titanium endpin on floor(left) vs 8mm Metal-rod endpin on floor(right) Cello: Cello-1 (8-year-old) 300 times slower, silent video
Reference post: -- https://advancedendpinholder.blogspot.com/ -- 93..Resonance Direction-A2 -- 93..Cello-1, Cello-2 on A -Resonance Direction-
Wolf tones are relating with the pure(/simple, perfect) vibration of top-plate. When the E(/F) pitch forced to shift slightly high or low, top-plate gives up the current wave cycle then creates a new one.
Cello: Cello-1 (8-year-old) 100 times slower, silent video
Reference post: --> https://advancedendpinholder.blogspot.com/ --> 63.Wolf tone --> 63. Memo for wolf tones
[ 2/29/2020 ] Labels: 1A4C#.Resonance A C# (278Hz, 1A4C#) Typical Resonance Simulation: Cello is often impacted by mechanical resonance of endpin. Left : Without endpin Right: On floor, Titanium endpin Cello: Cello-1 (8-year-old) 220 times slower, silent video Reference post: --> https://advancedendpinholder.blogspot.com/ --> 92..Resonance Direction-A --> 92..Cello-1 on A -V/H Amplitude Ratio-