Buzz sound when I play B note 3rd octave with piano tone 001 and few other tones.

[KVY]

 

Five days back I purchased ctx 9000.  when started playing, I notice buzz/electronic sound from left speaker. Issue with few tones.

 

For example 1st tone -001, when I play middle "b" note (3rd octave)  buzz sound is noticed. Make octave change to -1, issue shifted with tone at lower "b note" (2nd octave). Issue become noticable when sound of Speaker volume > = 50%.

If I play flute tone, I do not see similar issue.

 

So looks like issue with specific tones only with specific "b note 3rd octave 21st white key". 

 

Is this know issue with tones or issue with speaker?

 

Issue is unnoticeable in voice or video recording.

[Just Alex]

This issue is called cabinet resonance